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Add Tirdad patch to kernel #26

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Add Tirdad patch to kernel #26

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@0xsirus 0xsirus commented Feb 19, 2020

I've already prepared a kernel module to resolve an anonymity issue in TCP/IP protocol suite which is present in current implementations including in Linux kernel. The module hot-patched the kernel and installed a hook to change the functionality of the responsible function in the kernel. You can refer to these links to read more about the issue and the solution:
https://github.com/0xsirus/tirdad
https://github.com/Whonix/tirdad

However I found it also useful to have this patch applied into the kernel. So I prepared an equivalent of the kernel module and wrote this patch. A new sysctl option is added by this patch to give the users the ability to enable/disable the change made into the kernel by this patch.
The new option is called 'tcp_random_isn' and will be added to '/proc/sys/net/ipv4'.

thestinger and others added 30 commits February 6, 2020 00:48
It can make sense to disable this to reduce attack surface / complexity.
Signed-off-by: Daniel Micay <[email protected]>
anthraxx pushed a commit that referenced this pull request Jul 12, 2022
Release refcount after xas_set to fix UAF which may cause panic like this:

 page:ffffea000491fa40 refcount:1 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x1247e9
 head:ffffea000491fa00 order:3 compound_mapcount:0 compound_pincount:0
 memcg:ffff888104f91091
 flags: 0x2fffff80010200(slab|head|node=0|zone=2|lastcpupid=0x1fffff)
...
page dumped because: VM_BUG_ON_PAGE(PageTail(page))
 ------------[ cut here ]------------
 kernel BUG at include/linux/page-flags.h:632!
 invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN
 CPU: 1 PID: 7642 Comm: sh Not tainted 5.15.51-dirty #26
...
 Call Trace:
  <TASK>
  __invalidate_mapping_pages+0xe7/0x540
  drop_pagecache_sb+0x159/0x320
  iterate_supers+0x120/0x240
  drop_caches_sysctl_handler+0xaa/0xe0
  proc_sys_call_handler+0x2b4/0x480
  new_sync_write+0x3d6/0x5c0
  vfs_write+0x446/0x7a0
  ksys_write+0x105/0x210
  do_syscall_64+0x35/0x80
  entry_SYSCALL_64_after_hwframe+0x44/0xae
 RIP: 0033:0x7f52b5733130
...

This problem has been fixed on mainline by patch 6b24ca4 ("mm: Use
multi-index entries in the page cache") since it deletes the related code.

Fixes: 5c211ba ("mm: add and use find_lock_entries")
Signed-off-by: Liu Shixin <[email protected]>
Acked-by: Matthew Wilcox (Oracle) <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
anthraxx pushed a commit that referenced this pull request Jan 24, 2023
commit b8caf69 upstream.

Driver's probe allocates memory for RX FIFO (port->rx_fifo) based on
default RX FIFO depth, e.g. 16.  Later during serial startup the
qcom_geni_serial_port_setup() updates the RX FIFO depth
(port->rx_fifo_depth) to match real device capabilities, e.g. to 32.

The RX UART handle code will read "port->rx_fifo_depth" number of words
into "port->rx_fifo" buffer, thus exceeding the bounds.  This can be
observed in certain configurations with Qualcomm Bluetooth HCI UART
device and KASAN:

  Bluetooth: hci0: QCA Product ID   :0x00000010
  Bluetooth: hci0: QCA SOC Version  :0x400a0200
  Bluetooth: hci0: QCA ROM Version  :0x00000200
  Bluetooth: hci0: QCA Patch Version:0x00000d2b
  Bluetooth: hci0: QCA controller version 0x02000200
  Bluetooth: hci0: QCA Downloading qca/htbtfw20.tlv
  bluetooth hci0: Direct firmware load for qca/htbtfw20.tlv failed with error -2
  Bluetooth: hci0: QCA Failed to request file: qca/htbtfw20.tlv (-2)
  Bluetooth: hci0: QCA Failed to download patch (-2)
  ==================================================================
  BUG: KASAN: slab-out-of-bounds in handle_rx_uart+0xa8/0x18c
  Write of size 4 at addr ffff279347d578c0 by task swapper/0/0

  CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.1.0-rt5-00350-gb2450b7e00be-dirty #26
  Hardware name: Qualcomm Technologies, Inc. Robotics RB5 (DT)
  Call trace:
   dump_backtrace.part.0+0xe0/0xf0
   show_stack+0x18/0x40
   dump_stack_lvl+0x8c/0xb8
   print_report+0x188/0x488
   kasan_report+0xb4/0x100
   __asan_store4+0x80/0xa4
   handle_rx_uart+0xa8/0x18c
   qcom_geni_serial_handle_rx+0x84/0x9c
   qcom_geni_serial_isr+0x24c/0x760
   __handle_irq_event_percpu+0x108/0x500
   handle_irq_event+0x6c/0x110
   handle_fasteoi_irq+0x138/0x2cc
   generic_handle_domain_irq+0x48/0x64

If the RX FIFO depth changes after probe, be sure to resize the buffer.

Fixes: f9d690b ("tty: serial: qcom_geni_serial: Allocate port->rx_fifo buffer in probe")
Cc: <[email protected]>
Signed-off-by: Krzysztof Kozlowski <[email protected]>
Reviewed-by: Jiri Slaby <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
anthraxx pushed a commit that referenced this pull request Jan 24, 2023
commit b8caf69 upstream.

Driver's probe allocates memory for RX FIFO (port->rx_fifo) based on
default RX FIFO depth, e.g. 16.  Later during serial startup the
qcom_geni_serial_port_setup() updates the RX FIFO depth
(port->rx_fifo_depth) to match real device capabilities, e.g. to 32.

The RX UART handle code will read "port->rx_fifo_depth" number of words
into "port->rx_fifo" buffer, thus exceeding the bounds.  This can be
observed in certain configurations with Qualcomm Bluetooth HCI UART
device and KASAN:

  Bluetooth: hci0: QCA Product ID   :0x00000010
  Bluetooth: hci0: QCA SOC Version  :0x400a0200
  Bluetooth: hci0: QCA ROM Version  :0x00000200
  Bluetooth: hci0: QCA Patch Version:0x00000d2b
  Bluetooth: hci0: QCA controller version 0x02000200
  Bluetooth: hci0: QCA Downloading qca/htbtfw20.tlv
  bluetooth hci0: Direct firmware load for qca/htbtfw20.tlv failed with error -2
  Bluetooth: hci0: QCA Failed to request file: qca/htbtfw20.tlv (-2)
  Bluetooth: hci0: QCA Failed to download patch (-2)
  ==================================================================
  BUG: KASAN: slab-out-of-bounds in handle_rx_uart+0xa8/0x18c
  Write of size 4 at addr ffff279347d578c0 by task swapper/0/0

  CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.1.0-rt5-00350-gb2450b7e00be-dirty #26
  Hardware name: Qualcomm Technologies, Inc. Robotics RB5 (DT)
  Call trace:
   dump_backtrace.part.0+0xe0/0xf0
   show_stack+0x18/0x40
   dump_stack_lvl+0x8c/0xb8
   print_report+0x188/0x488
   kasan_report+0xb4/0x100
   __asan_store4+0x80/0xa4
   handle_rx_uart+0xa8/0x18c
   qcom_geni_serial_handle_rx+0x84/0x9c
   qcom_geni_serial_isr+0x24c/0x760
   __handle_irq_event_percpu+0x108/0x500
   handle_irq_event+0x6c/0x110
   handle_fasteoi_irq+0x138/0x2cc
   generic_handle_domain_irq+0x48/0x64

If the RX FIFO depth changes after probe, be sure to resize the buffer.

Fixes: f9d690b ("tty: serial: qcom_geni_serial: Allocate port->rx_fifo buffer in probe")
Cc: <[email protected]>
Signed-off-by: Krzysztof Kozlowski <[email protected]>
Reviewed-by: Jiri Slaby <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
anthraxx pushed a commit that referenced this pull request Jan 24, 2023
commit b8caf69 upstream.

Driver's probe allocates memory for RX FIFO (port->rx_fifo) based on
default RX FIFO depth, e.g. 16.  Later during serial startup the
qcom_geni_serial_port_setup() updates the RX FIFO depth
(port->rx_fifo_depth) to match real device capabilities, e.g. to 32.

The RX UART handle code will read "port->rx_fifo_depth" number of words
into "port->rx_fifo" buffer, thus exceeding the bounds.  This can be
observed in certain configurations with Qualcomm Bluetooth HCI UART
device and KASAN:

  Bluetooth: hci0: QCA Product ID   :0x00000010
  Bluetooth: hci0: QCA SOC Version  :0x400a0200
  Bluetooth: hci0: QCA ROM Version  :0x00000200
  Bluetooth: hci0: QCA Patch Version:0x00000d2b
  Bluetooth: hci0: QCA controller version 0x02000200
  Bluetooth: hci0: QCA Downloading qca/htbtfw20.tlv
  bluetooth hci0: Direct firmware load for qca/htbtfw20.tlv failed with error -2
  Bluetooth: hci0: QCA Failed to request file: qca/htbtfw20.tlv (-2)
  Bluetooth: hci0: QCA Failed to download patch (-2)
  ==================================================================
  BUG: KASAN: slab-out-of-bounds in handle_rx_uart+0xa8/0x18c
  Write of size 4 at addr ffff279347d578c0 by task swapper/0/0

  CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.1.0-rt5-00350-gb2450b7e00be-dirty #26
  Hardware name: Qualcomm Technologies, Inc. Robotics RB5 (DT)
  Call trace:
   dump_backtrace.part.0+0xe0/0xf0
   show_stack+0x18/0x40
   dump_stack_lvl+0x8c/0xb8
   print_report+0x188/0x488
   kasan_report+0xb4/0x100
   __asan_store4+0x80/0xa4
   handle_rx_uart+0xa8/0x18c
   qcom_geni_serial_handle_rx+0x84/0x9c
   qcom_geni_serial_isr+0x24c/0x760
   __handle_irq_event_percpu+0x108/0x500
   handle_irq_event+0x6c/0x110
   handle_fasteoi_irq+0x138/0x2cc
   generic_handle_domain_irq+0x48/0x64

If the RX FIFO depth changes after probe, be sure to resize the buffer.

Fixes: f9d690b ("tty: serial: qcom_geni_serial: Allocate port->rx_fifo buffer in probe")
Cc: <[email protected]>
Signed-off-by: Krzysztof Kozlowski <[email protected]>
Reviewed-by: Jiri Slaby <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
anthraxx pushed a commit that referenced this pull request Jun 27, 2023
[ Upstream commit 37c3b9f ]

The cited commit adds a compeletion to remove dependency on rtnl
lock. But it causes a deadlock for multiple encapsulations:

 crash> bt ffff8aece8a64000
 PID: 1514557  TASK: ffff8aece8a64000  CPU: 3    COMMAND: "tc"
  #0 [ffffa6d14183f368] __schedule at ffffffffb8ba7f45
  #1 [ffffa6d14183f3f8] schedule at ffffffffb8ba8418
  #2 [ffffa6d14183f418] schedule_preempt_disabled at ffffffffb8ba8898
  #3 [ffffa6d14183f428] __mutex_lock at ffffffffb8baa7f8
  #4 [ffffa6d14183f4d0] mutex_lock_nested at ffffffffb8baabeb
  #5 [ffffa6d14183f4e0] mlx5e_attach_encap at ffffffffc0f48c17 [mlx5_core]
  #6 [ffffa6d14183f628] mlx5e_tc_add_fdb_flow at ffffffffc0f39680 [mlx5_core]
  #7 [ffffa6d14183f688] __mlx5e_add_fdb_flow at ffffffffc0f3b636 [mlx5_core]
  #8 [ffffa6d14183f6f0] mlx5e_tc_add_flow at ffffffffc0f3bcdf [mlx5_core]
  #9 [ffffa6d14183f728] mlx5e_configure_flower at ffffffffc0f3c1d1 [mlx5_core]
 #10 [ffffa6d14183f790] mlx5e_rep_setup_tc_cls_flower at ffffffffc0f3d529 [mlx5_core]
 #11 [ffffa6d14183f7a0] mlx5e_rep_setup_tc_cb at ffffffffc0f3d714 [mlx5_core]
 #12 [ffffa6d14183f7b0] tc_setup_cb_add at ffffffffb8931bb8
 #13 [ffffa6d14183f810] fl_hw_replace_filter at ffffffffc0dae901 [cls_flower]
 #14 [ffffa6d14183f8d8] fl_change at ffffffffc0db5c57 [cls_flower]
 #15 [ffffa6d14183f970] tc_new_tfilter at ffffffffb8936047
 #16 [ffffa6d14183fac8] rtnetlink_rcv_msg at ffffffffb88c7c31
 #17 [ffffa6d14183fb50] netlink_rcv_skb at ffffffffb8942853
 #18 [ffffa6d14183fbc0] rtnetlink_rcv at ffffffffb88c1835
 #19 [ffffa6d14183fbd0] netlink_unicast at ffffffffb8941f27
 #20 [ffffa6d14183fc18] netlink_sendmsg at ffffffffb8942245
 #21 [ffffa6d14183fc98] sock_sendmsg at ffffffffb887d482
 #22 [ffffa6d14183fcb8] ____sys_sendmsg at ffffffffb887d81a
 #23 [ffffa6d14183fd38] ___sys_sendmsg at ffffffffb88806e2
 #24 [ffffa6d14183fe90] __sys_sendmsg at ffffffffb88807a2
 #25 [ffffa6d14183ff28] __x64_sys_sendmsg at ffffffffb888080f
 #26 [ffffa6d14183ff38] do_syscall_64 at ffffffffb8b9b6a8
 #27 [ffffa6d14183ff50] entry_SYSCALL_64_after_hwframe at ffffffffb8c0007c
 crash> bt 0xffff8aeb07544000
 PID: 1110766  TASK: ffff8aeb07544000  CPU: 0    COMMAND: "kworker/u20:9"
  #0 [ffffa6d14e6b7bd8] __schedule at ffffffffb8ba7f45
  #1 [ffffa6d14e6b7c68] schedule at ffffffffb8ba8418
  #2 [ffffa6d14e6b7c88] schedule_timeout at ffffffffb8baef88
  #3 [ffffa6d14e6b7d10] wait_for_completion at ffffffffb8ba968b
  #4 [ffffa6d14e6b7d60] mlx5e_take_all_encap_flows at ffffffffc0f47ec4 [mlx5_core]
  #5 [ffffa6d14e6b7da0] mlx5e_rep_update_flows at ffffffffc0f3e734 [mlx5_core]
  #6 [ffffa6d14e6b7df8] mlx5e_rep_neigh_update at ffffffffc0f400bb [mlx5_core]
  #7 [ffffa6d14e6b7e50] process_one_work at ffffffffb80acc9c
  #8 [ffffa6d14e6b7ed0] worker_thread at ffffffffb80ad012
  #9 [ffffa6d14e6b7f10] kthread at ffffffffb80b615d
 #10 [ffffa6d14e6b7f50] ret_from_fork at ffffffffb8001b2f

After the first encap is attached, flow will be added to encap
entry's flows list. If neigh update is running at this time, the
following encaps of the flow can't hold the encap_tbl_lock and
sleep. If neigh update thread is waiting for that flow's init_done,
deadlock happens.

Fix it by holding lock outside of the for loop. If neigh update is
running, prevent encap flows from offloading. Since the lock is held
outside of the for loop, concurrent creation of encap entries is not
allowed. So remove unnecessary wait_for_completion call for res_ready.

Fixes: 95435ad ("net/mlx5e: Only access fully initialized flows in neigh update")
Signed-off-by: Chris Mi <[email protected]>
Reviewed-by: Roi Dayan <[email protected]>
Reviewed-by: Vlad Buslov <[email protected]>
Signed-off-by: Saeed Mahameed <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
anthraxx pushed a commit that referenced this pull request Jul 11, 2023
[ Upstream commit 8d21155 ]

adjust_inuse_and_calc_cost() use spin_lock_irq() and IRQ will be enabled
when unlock. DEADLOCK might happen if we have held other locks and disabled
IRQ before invoking it.

Fix it by using spin_lock_irqsave() instead, which can keep IRQ state
consistent with before when unlock.

  ================================
  WARNING: inconsistent lock state
  5.10.0-02758-g8e5f91fd772f #26 Not tainted
  --------------------------------
  inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
  kworker/2:3/388 [HC0[0]:SC0[0]:HE0:SE1] takes:
  ffff888118c00c28 (&bfqd->lock){?.-.}-{2:2}, at: spin_lock_irq
  ffff888118c00c28 (&bfqd->lock){?.-.}-{2:2}, at: bfq_bio_merge+0x141/0x390
  {IN-HARDIRQ-W} state was registered at:
    __lock_acquire+0x3d7/0x1070
    lock_acquire+0x197/0x4a0
    __raw_spin_lock_irqsave
    _raw_spin_lock_irqsave+0x3b/0x60
    bfq_idle_slice_timer_body
    bfq_idle_slice_timer+0x53/0x1d0
    __run_hrtimer+0x477/0xa70
    __hrtimer_run_queues+0x1c6/0x2d0
    hrtimer_interrupt+0x302/0x9e0
    local_apic_timer_interrupt
    __sysvec_apic_timer_interrupt+0xfd/0x420
    run_sysvec_on_irqstack_cond
    sysvec_apic_timer_interrupt+0x46/0xa0
    asm_sysvec_apic_timer_interrupt+0x12/0x20
  irq event stamp: 837522
  hardirqs last  enabled at (837521): [<ffffffff84b9419d>] __raw_spin_unlock_irqrestore
  hardirqs last  enabled at (837521): [<ffffffff84b9419d>] _raw_spin_unlock_irqrestore+0x3d/0x40
  hardirqs last disabled at (837522): [<ffffffff84b93fa3>] __raw_spin_lock_irq
  hardirqs last disabled at (837522): [<ffffffff84b93fa3>] _raw_spin_lock_irq+0x43/0x50
  softirqs last  enabled at (835852): [<ffffffff84e00558>] __do_softirq+0x558/0x8ec
  softirqs last disabled at (835845): [<ffffffff84c010ff>] asm_call_irq_on_stack+0xf/0x20

  other info that might help us debug this:
   Possible unsafe locking scenario:

         CPU0
         ----
    lock(&bfqd->lock);
    <Interrupt>
      lock(&bfqd->lock);

   *** DEADLOCK ***

  3 locks held by kworker/2:3/388:
   #0: ffff888107af0f38 ((wq_completion)kthrotld){+.+.}-{0:0}, at: process_one_work+0x742/0x13f0
   #1: ffff8881176bfdd8 ((work_completion)(&td->dispatch_work)){+.+.}-{0:0}, at: process_one_work+0x777/0x13f0
   #2: ffff888118c00c28 (&bfqd->lock){?.-.}-{2:2}, at: spin_lock_irq
   #2: ffff888118c00c28 (&bfqd->lock){?.-.}-{2:2}, at: bfq_bio_merge+0x141/0x390

  stack backtrace:
  CPU: 2 PID: 388 Comm: kworker/2:3 Not tainted 5.10.0-02758-g8e5f91fd772f #26
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
  Workqueue: kthrotld blk_throtl_dispatch_work_fn
  Call Trace:
   __dump_stack lib/dump_stack.c:77 [inline]
   dump_stack+0x107/0x167
   print_usage_bug
   valid_state
   mark_lock_irq.cold+0x32/0x3a
   mark_lock+0x693/0xbc0
   mark_held_locks+0x9e/0xe0
   __trace_hardirqs_on_caller
   lockdep_hardirqs_on_prepare.part.0+0x151/0x360
   trace_hardirqs_on+0x5b/0x180
   __raw_spin_unlock_irq
   _raw_spin_unlock_irq+0x24/0x40
   spin_unlock_irq
   adjust_inuse_and_calc_cost+0x4fb/0x970
   ioc_rqos_merge+0x277/0x740
   __rq_qos_merge+0x62/0xb0
   rq_qos_merge
   bio_attempt_back_merge+0x12c/0x4a0
   blk_mq_sched_try_merge+0x1b6/0x4d0
   bfq_bio_merge+0x24a/0x390
   __blk_mq_sched_bio_merge+0xa6/0x460
   blk_mq_sched_bio_merge
   blk_mq_submit_bio+0x2e7/0x1ee0
   __submit_bio_noacct_mq+0x175/0x3b0
   submit_bio_noacct+0x1fb/0x270
   blk_throtl_dispatch_work_fn+0x1ef/0x2b0
   process_one_work+0x83e/0x13f0
   process_scheduled_works
   worker_thread+0x7e3/0xd80
   kthread+0x353/0x470
   ret_from_fork+0x1f/0x30

Fixes: b0853ab ("blk-iocost: revamp in-period donation snapbacks")
Signed-off-by: Li Nan <[email protected]>
Acked-by: Tejun Heo <[email protected]>
Reviewed-by: Yu Kuai <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
anthraxx pushed a commit that referenced this pull request Jul 19, 2023
[ Upstream commit 8d21155 ]

adjust_inuse_and_calc_cost() use spin_lock_irq() and IRQ will be enabled
when unlock. DEADLOCK might happen if we have held other locks and disabled
IRQ before invoking it.

Fix it by using spin_lock_irqsave() instead, which can keep IRQ state
consistent with before when unlock.

  ================================
  WARNING: inconsistent lock state
  5.10.0-02758-g8e5f91fd772f #26 Not tainted
  --------------------------------
  inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
  kworker/2:3/388 [HC0[0]:SC0[0]:HE0:SE1] takes:
  ffff888118c00c28 (&bfqd->lock){?.-.}-{2:2}, at: spin_lock_irq
  ffff888118c00c28 (&bfqd->lock){?.-.}-{2:2}, at: bfq_bio_merge+0x141/0x390
  {IN-HARDIRQ-W} state was registered at:
    __lock_acquire+0x3d7/0x1070
    lock_acquire+0x197/0x4a0
    __raw_spin_lock_irqsave
    _raw_spin_lock_irqsave+0x3b/0x60
    bfq_idle_slice_timer_body
    bfq_idle_slice_timer+0x53/0x1d0
    __run_hrtimer+0x477/0xa70
    __hrtimer_run_queues+0x1c6/0x2d0
    hrtimer_interrupt+0x302/0x9e0
    local_apic_timer_interrupt
    __sysvec_apic_timer_interrupt+0xfd/0x420
    run_sysvec_on_irqstack_cond
    sysvec_apic_timer_interrupt+0x46/0xa0
    asm_sysvec_apic_timer_interrupt+0x12/0x20
  irq event stamp: 837522
  hardirqs last  enabled at (837521): [<ffffffff84b9419d>] __raw_spin_unlock_irqrestore
  hardirqs last  enabled at (837521): [<ffffffff84b9419d>] _raw_spin_unlock_irqrestore+0x3d/0x40
  hardirqs last disabled at (837522): [<ffffffff84b93fa3>] __raw_spin_lock_irq
  hardirqs last disabled at (837522): [<ffffffff84b93fa3>] _raw_spin_lock_irq+0x43/0x50
  softirqs last  enabled at (835852): [<ffffffff84e00558>] __do_softirq+0x558/0x8ec
  softirqs last disabled at (835845): [<ffffffff84c010ff>] asm_call_irq_on_stack+0xf/0x20

  other info that might help us debug this:
   Possible unsafe locking scenario:

         CPU0
         ----
    lock(&bfqd->lock);
    <Interrupt>
      lock(&bfqd->lock);

   *** DEADLOCK ***

  3 locks held by kworker/2:3/388:
   #0: ffff888107af0f38 ((wq_completion)kthrotld){+.+.}-{0:0}, at: process_one_work+0x742/0x13f0
   #1: ffff8881176bfdd8 ((work_completion)(&td->dispatch_work)){+.+.}-{0:0}, at: process_one_work+0x777/0x13f0
   #2: ffff888118c00c28 (&bfqd->lock){?.-.}-{2:2}, at: spin_lock_irq
   #2: ffff888118c00c28 (&bfqd->lock){?.-.}-{2:2}, at: bfq_bio_merge+0x141/0x390

  stack backtrace:
  CPU: 2 PID: 388 Comm: kworker/2:3 Not tainted 5.10.0-02758-g8e5f91fd772f #26
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
  Workqueue: kthrotld blk_throtl_dispatch_work_fn
  Call Trace:
   __dump_stack lib/dump_stack.c:77 [inline]
   dump_stack+0x107/0x167
   print_usage_bug
   valid_state
   mark_lock_irq.cold+0x32/0x3a
   mark_lock+0x693/0xbc0
   mark_held_locks+0x9e/0xe0
   __trace_hardirqs_on_caller
   lockdep_hardirqs_on_prepare.part.0+0x151/0x360
   trace_hardirqs_on+0x5b/0x180
   __raw_spin_unlock_irq
   _raw_spin_unlock_irq+0x24/0x40
   spin_unlock_irq
   adjust_inuse_and_calc_cost+0x4fb/0x970
   ioc_rqos_merge+0x277/0x740
   __rq_qos_merge+0x62/0xb0
   rq_qos_merge
   bio_attempt_back_merge+0x12c/0x4a0
   blk_mq_sched_try_merge+0x1b6/0x4d0
   bfq_bio_merge+0x24a/0x390
   __blk_mq_sched_bio_merge+0xa6/0x460
   blk_mq_sched_bio_merge
   blk_mq_submit_bio+0x2e7/0x1ee0
   __submit_bio_noacct_mq+0x175/0x3b0
   submit_bio_noacct+0x1fb/0x270
   blk_throtl_dispatch_work_fn+0x1ef/0x2b0
   process_one_work+0x83e/0x13f0
   process_scheduled_works
   worker_thread+0x7e3/0xd80
   kthread+0x353/0x470
   ret_from_fork+0x1f/0x30

Fixes: b0853ab ("blk-iocost: revamp in-period donation snapbacks")
Signed-off-by: Li Nan <[email protected]>
Acked-by: Tejun Heo <[email protected]>
Reviewed-by: Yu Kuai <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
anthraxx pushed a commit that referenced this pull request Jul 19, 2023
[ Upstream commit 8d21155 ]

adjust_inuse_and_calc_cost() use spin_lock_irq() and IRQ will be enabled
when unlock. DEADLOCK might happen if we have held other locks and disabled
IRQ before invoking it.

Fix it by using spin_lock_irqsave() instead, which can keep IRQ state
consistent with before when unlock.

  ================================
  WARNING: inconsistent lock state
  5.10.0-02758-g8e5f91fd772f #26 Not tainted
  --------------------------------
  inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
  kworker/2:3/388 [HC0[0]:SC0[0]:HE0:SE1] takes:
  ffff888118c00c28 (&bfqd->lock){?.-.}-{2:2}, at: spin_lock_irq
  ffff888118c00c28 (&bfqd->lock){?.-.}-{2:2}, at: bfq_bio_merge+0x141/0x390
  {IN-HARDIRQ-W} state was registered at:
    __lock_acquire+0x3d7/0x1070
    lock_acquire+0x197/0x4a0
    __raw_spin_lock_irqsave
    _raw_spin_lock_irqsave+0x3b/0x60
    bfq_idle_slice_timer_body
    bfq_idle_slice_timer+0x53/0x1d0
    __run_hrtimer+0x477/0xa70
    __hrtimer_run_queues+0x1c6/0x2d0
    hrtimer_interrupt+0x302/0x9e0
    local_apic_timer_interrupt
    __sysvec_apic_timer_interrupt+0xfd/0x420
    run_sysvec_on_irqstack_cond
    sysvec_apic_timer_interrupt+0x46/0xa0
    asm_sysvec_apic_timer_interrupt+0x12/0x20
  irq event stamp: 837522
  hardirqs last  enabled at (837521): [<ffffffff84b9419d>] __raw_spin_unlock_irqrestore
  hardirqs last  enabled at (837521): [<ffffffff84b9419d>] _raw_spin_unlock_irqrestore+0x3d/0x40
  hardirqs last disabled at (837522): [<ffffffff84b93fa3>] __raw_spin_lock_irq
  hardirqs last disabled at (837522): [<ffffffff84b93fa3>] _raw_spin_lock_irq+0x43/0x50
  softirqs last  enabled at (835852): [<ffffffff84e00558>] __do_softirq+0x558/0x8ec
  softirqs last disabled at (835845): [<ffffffff84c010ff>] asm_call_irq_on_stack+0xf/0x20

  other info that might help us debug this:
   Possible unsafe locking scenario:

         CPU0
         ----
    lock(&bfqd->lock);
    <Interrupt>
      lock(&bfqd->lock);

   *** DEADLOCK ***

  3 locks held by kworker/2:3/388:
   #0: ffff888107af0f38 ((wq_completion)kthrotld){+.+.}-{0:0}, at: process_one_work+0x742/0x13f0
   #1: ffff8881176bfdd8 ((work_completion)(&td->dispatch_work)){+.+.}-{0:0}, at: process_one_work+0x777/0x13f0
   #2: ffff888118c00c28 (&bfqd->lock){?.-.}-{2:2}, at: spin_lock_irq
   #2: ffff888118c00c28 (&bfqd->lock){?.-.}-{2:2}, at: bfq_bio_merge+0x141/0x390

  stack backtrace:
  CPU: 2 PID: 388 Comm: kworker/2:3 Not tainted 5.10.0-02758-g8e5f91fd772f #26
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
  Workqueue: kthrotld blk_throtl_dispatch_work_fn
  Call Trace:
   __dump_stack lib/dump_stack.c:77 [inline]
   dump_stack+0x107/0x167
   print_usage_bug
   valid_state
   mark_lock_irq.cold+0x32/0x3a
   mark_lock+0x693/0xbc0
   mark_held_locks+0x9e/0xe0
   __trace_hardirqs_on_caller
   lockdep_hardirqs_on_prepare.part.0+0x151/0x360
   trace_hardirqs_on+0x5b/0x180
   __raw_spin_unlock_irq
   _raw_spin_unlock_irq+0x24/0x40
   spin_unlock_irq
   adjust_inuse_and_calc_cost+0x4fb/0x970
   ioc_rqos_merge+0x277/0x740
   __rq_qos_merge+0x62/0xb0
   rq_qos_merge
   bio_attempt_back_merge+0x12c/0x4a0
   blk_mq_sched_try_merge+0x1b6/0x4d0
   bfq_bio_merge+0x24a/0x390
   __blk_mq_sched_bio_merge+0xa6/0x460
   blk_mq_sched_bio_merge
   blk_mq_submit_bio+0x2e7/0x1ee0
   __submit_bio_noacct_mq+0x175/0x3b0
   submit_bio_noacct+0x1fb/0x270
   blk_throtl_dispatch_work_fn+0x1ef/0x2b0
   process_one_work+0x83e/0x13f0
   process_scheduled_works
   worker_thread+0x7e3/0xd80
   kthread+0x353/0x470
   ret_from_fork+0x1f/0x30

Fixes: b0853ab ("blk-iocost: revamp in-period donation snapbacks")
Signed-off-by: Li Nan <[email protected]>
Acked-by: Tejun Heo <[email protected]>
Reviewed-by: Yu Kuai <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
anthraxx pushed a commit that referenced this pull request Jul 24, 2023
[ Upstream commit 8d21155 ]

adjust_inuse_and_calc_cost() use spin_lock_irq() and IRQ will be enabled
when unlock. DEADLOCK might happen if we have held other locks and disabled
IRQ before invoking it.

Fix it by using spin_lock_irqsave() instead, which can keep IRQ state
consistent with before when unlock.

  ================================
  WARNING: inconsistent lock state
  5.10.0-02758-g8e5f91fd772f #26 Not tainted
  --------------------------------
  inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
  kworker/2:3/388 [HC0[0]:SC0[0]:HE0:SE1] takes:
  ffff888118c00c28 (&bfqd->lock){?.-.}-{2:2}, at: spin_lock_irq
  ffff888118c00c28 (&bfqd->lock){?.-.}-{2:2}, at: bfq_bio_merge+0x141/0x390
  {IN-HARDIRQ-W} state was registered at:
    __lock_acquire+0x3d7/0x1070
    lock_acquire+0x197/0x4a0
    __raw_spin_lock_irqsave
    _raw_spin_lock_irqsave+0x3b/0x60
    bfq_idle_slice_timer_body
    bfq_idle_slice_timer+0x53/0x1d0
    __run_hrtimer+0x477/0xa70
    __hrtimer_run_queues+0x1c6/0x2d0
    hrtimer_interrupt+0x302/0x9e0
    local_apic_timer_interrupt
    __sysvec_apic_timer_interrupt+0xfd/0x420
    run_sysvec_on_irqstack_cond
    sysvec_apic_timer_interrupt+0x46/0xa0
    asm_sysvec_apic_timer_interrupt+0x12/0x20
  irq event stamp: 837522
  hardirqs last  enabled at (837521): [<ffffffff84b9419d>] __raw_spin_unlock_irqrestore
  hardirqs last  enabled at (837521): [<ffffffff84b9419d>] _raw_spin_unlock_irqrestore+0x3d/0x40
  hardirqs last disabled at (837522): [<ffffffff84b93fa3>] __raw_spin_lock_irq
  hardirqs last disabled at (837522): [<ffffffff84b93fa3>] _raw_spin_lock_irq+0x43/0x50
  softirqs last  enabled at (835852): [<ffffffff84e00558>] __do_softirq+0x558/0x8ec
  softirqs last disabled at (835845): [<ffffffff84c010ff>] asm_call_irq_on_stack+0xf/0x20

  other info that might help us debug this:
   Possible unsafe locking scenario:

         CPU0
         ----
    lock(&bfqd->lock);
    <Interrupt>
      lock(&bfqd->lock);

   *** DEADLOCK ***

  3 locks held by kworker/2:3/388:
   #0: ffff888107af0f38 ((wq_completion)kthrotld){+.+.}-{0:0}, at: process_one_work+0x742/0x13f0
   #1: ffff8881176bfdd8 ((work_completion)(&td->dispatch_work)){+.+.}-{0:0}, at: process_one_work+0x777/0x13f0
   #2: ffff888118c00c28 (&bfqd->lock){?.-.}-{2:2}, at: spin_lock_irq
   #2: ffff888118c00c28 (&bfqd->lock){?.-.}-{2:2}, at: bfq_bio_merge+0x141/0x390

  stack backtrace:
  CPU: 2 PID: 388 Comm: kworker/2:3 Not tainted 5.10.0-02758-g8e5f91fd772f #26
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
  Workqueue: kthrotld blk_throtl_dispatch_work_fn
  Call Trace:
   __dump_stack lib/dump_stack.c:77 [inline]
   dump_stack+0x107/0x167
   print_usage_bug
   valid_state
   mark_lock_irq.cold+0x32/0x3a
   mark_lock+0x693/0xbc0
   mark_held_locks+0x9e/0xe0
   __trace_hardirqs_on_caller
   lockdep_hardirqs_on_prepare.part.0+0x151/0x360
   trace_hardirqs_on+0x5b/0x180
   __raw_spin_unlock_irq
   _raw_spin_unlock_irq+0x24/0x40
   spin_unlock_irq
   adjust_inuse_and_calc_cost+0x4fb/0x970
   ioc_rqos_merge+0x277/0x740
   __rq_qos_merge+0x62/0xb0
   rq_qos_merge
   bio_attempt_back_merge+0x12c/0x4a0
   blk_mq_sched_try_merge+0x1b6/0x4d0
   bfq_bio_merge+0x24a/0x390
   __blk_mq_sched_bio_merge+0xa6/0x460
   blk_mq_sched_bio_merge
   blk_mq_submit_bio+0x2e7/0x1ee0
   __submit_bio_noacct_mq+0x175/0x3b0
   submit_bio_noacct+0x1fb/0x270
   blk_throtl_dispatch_work_fn+0x1ef/0x2b0
   process_one_work+0x83e/0x13f0
   process_scheduled_works
   worker_thread+0x7e3/0xd80
   kthread+0x353/0x470
   ret_from_fork+0x1f/0x30

Fixes: b0853ab ("blk-iocost: revamp in-period donation snapbacks")
Signed-off-by: Li Nan <[email protected]>
Acked-by: Tejun Heo <[email protected]>
Reviewed-by: Yu Kuai <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
anthraxx pushed a commit that referenced this pull request Jul 31, 2023
[ Upstream commit 8d21155 ]

adjust_inuse_and_calc_cost() use spin_lock_irq() and IRQ will be enabled
when unlock. DEADLOCK might happen if we have held other locks and disabled
IRQ before invoking it.

Fix it by using spin_lock_irqsave() instead, which can keep IRQ state
consistent with before when unlock.

  ================================
  WARNING: inconsistent lock state
  5.10.0-02758-g8e5f91fd772f #26 Not tainted
  --------------------------------
  inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
  kworker/2:3/388 [HC0[0]:SC0[0]:HE0:SE1] takes:
  ffff888118c00c28 (&bfqd->lock){?.-.}-{2:2}, at: spin_lock_irq
  ffff888118c00c28 (&bfqd->lock){?.-.}-{2:2}, at: bfq_bio_merge+0x141/0x390
  {IN-HARDIRQ-W} state was registered at:
    __lock_acquire+0x3d7/0x1070
    lock_acquire+0x197/0x4a0
    __raw_spin_lock_irqsave
    _raw_spin_lock_irqsave+0x3b/0x60
    bfq_idle_slice_timer_body
    bfq_idle_slice_timer+0x53/0x1d0
    __run_hrtimer+0x477/0xa70
    __hrtimer_run_queues+0x1c6/0x2d0
    hrtimer_interrupt+0x302/0x9e0
    local_apic_timer_interrupt
    __sysvec_apic_timer_interrupt+0xfd/0x420
    run_sysvec_on_irqstack_cond
    sysvec_apic_timer_interrupt+0x46/0xa0
    asm_sysvec_apic_timer_interrupt+0x12/0x20
  irq event stamp: 837522
  hardirqs last  enabled at (837521): [<ffffffff84b9419d>] __raw_spin_unlock_irqrestore
  hardirqs last  enabled at (837521): [<ffffffff84b9419d>] _raw_spin_unlock_irqrestore+0x3d/0x40
  hardirqs last disabled at (837522): [<ffffffff84b93fa3>] __raw_spin_lock_irq
  hardirqs last disabled at (837522): [<ffffffff84b93fa3>] _raw_spin_lock_irq+0x43/0x50
  softirqs last  enabled at (835852): [<ffffffff84e00558>] __do_softirq+0x558/0x8ec
  softirqs last disabled at (835845): [<ffffffff84c010ff>] asm_call_irq_on_stack+0xf/0x20

  other info that might help us debug this:
   Possible unsafe locking scenario:

         CPU0
         ----
    lock(&bfqd->lock);
    <Interrupt>
      lock(&bfqd->lock);

   *** DEADLOCK ***

  3 locks held by kworker/2:3/388:
   #0: ffff888107af0f38 ((wq_completion)kthrotld){+.+.}-{0:0}, at: process_one_work+0x742/0x13f0
   #1: ffff8881176bfdd8 ((work_completion)(&td->dispatch_work)){+.+.}-{0:0}, at: process_one_work+0x777/0x13f0
   #2: ffff888118c00c28 (&bfqd->lock){?.-.}-{2:2}, at: spin_lock_irq
   #2: ffff888118c00c28 (&bfqd->lock){?.-.}-{2:2}, at: bfq_bio_merge+0x141/0x390

  stack backtrace:
  CPU: 2 PID: 388 Comm: kworker/2:3 Not tainted 5.10.0-02758-g8e5f91fd772f #26
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
  Workqueue: kthrotld blk_throtl_dispatch_work_fn
  Call Trace:
   __dump_stack lib/dump_stack.c:77 [inline]
   dump_stack+0x107/0x167
   print_usage_bug
   valid_state
   mark_lock_irq.cold+0x32/0x3a
   mark_lock+0x693/0xbc0
   mark_held_locks+0x9e/0xe0
   __trace_hardirqs_on_caller
   lockdep_hardirqs_on_prepare.part.0+0x151/0x360
   trace_hardirqs_on+0x5b/0x180
   __raw_spin_unlock_irq
   _raw_spin_unlock_irq+0x24/0x40
   spin_unlock_irq
   adjust_inuse_and_calc_cost+0x4fb/0x970
   ioc_rqos_merge+0x277/0x740
   __rq_qos_merge+0x62/0xb0
   rq_qos_merge
   bio_attempt_back_merge+0x12c/0x4a0
   blk_mq_sched_try_merge+0x1b6/0x4d0
   bfq_bio_merge+0x24a/0x390
   __blk_mq_sched_bio_merge+0xa6/0x460
   blk_mq_sched_bio_merge
   blk_mq_submit_bio+0x2e7/0x1ee0
   __submit_bio_noacct_mq+0x175/0x3b0
   submit_bio_noacct+0x1fb/0x270
   blk_throtl_dispatch_work_fn+0x1ef/0x2b0
   process_one_work+0x83e/0x13f0
   process_scheduled_works
   worker_thread+0x7e3/0xd80
   kthread+0x353/0x470
   ret_from_fork+0x1f/0x30

Fixes: b0853ab ("blk-iocost: revamp in-period donation snapbacks")
Signed-off-by: Li Nan <[email protected]>
Acked-by: Tejun Heo <[email protected]>
Reviewed-by: Yu Kuai <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
anthraxx pushed a commit that referenced this pull request Sep 14, 2023
commit 2ea3528 upstream.

Commit bf5c25d ("skbuff: in skb_segment, call zerocopy functions
once per nskb") added the call to zero copy functions in skb_segment().
The change introduced a bug in skb_segment() because skb_orphan_frags()
may possibly change the number of fragments or allocate new fragments
altogether leaving nrfrags and frag to point to the old values. This can
cause a panic with stacktrace like the one below.

[  193.894380] BUG: kernel NULL pointer dereference, address: 00000000000000bc
[  193.895273] CPU: 13 PID: 18164 Comm: vh-net-17428 Kdump: loaded Tainted: G           O      5.15.123+ #26
[  193.903919] RIP: 0010:skb_segment+0xb0e/0x12f0
[  194.021892] Call Trace:
[  194.027422]  <TASK>
[  194.072861]  tcp_gso_segment+0x107/0x540
[  194.082031]  inet_gso_segment+0x15c/0x3d0
[  194.090783]  skb_mac_gso_segment+0x9f/0x110
[  194.095016]  __skb_gso_segment+0xc1/0x190
[  194.103131]  netem_enqueue+0x290/0xb10 [sch_netem]
[  194.107071]  dev_qdisc_enqueue+0x16/0x70
[  194.110884]  __dev_queue_xmit+0x63b/0xb30
[  194.121670]  bond_start_xmit+0x159/0x380 [bonding]
[  194.128506]  dev_hard_start_xmit+0xc3/0x1e0
[  194.131787]  __dev_queue_xmit+0x8a0/0xb30
[  194.138225]  macvlan_start_xmit+0x4f/0x100 [macvlan]
[  194.141477]  dev_hard_start_xmit+0xc3/0x1e0
[  194.144622]  sch_direct_xmit+0xe3/0x280
[  194.147748]  __dev_queue_xmit+0x54a/0xb30
[  194.154131]  tap_get_user+0x2a8/0x9c0 [tap]
[  194.157358]  tap_sendmsg+0x52/0x8e0 [tap]
[  194.167049]  handle_tx_zerocopy+0x14e/0x4c0 [vhost_net]
[  194.173631]  handle_tx+0xcd/0xe0 [vhost_net]
[  194.176959]  vhost_worker+0x76/0xb0 [vhost]
[  194.183667]  kthread+0x118/0x140
[  194.190358]  ret_from_fork+0x1f/0x30
[  194.193670]  </TASK>

In this case calling skb_orphan_frags() updated nr_frags leaving nrfrags
local variable in skb_segment() stale. This resulted in the code hitting
i >= nrfrags prematurely and trying to move to next frag_skb using
list_skb pointer, which was NULL, and caused kernel panic. Move the call
to zero copy functions before using frags and nr_frags.

Fixes: bf5c25d ("skbuff: in skb_segment, call zerocopy functions once per nskb")
Signed-off-by: Mohamed Khalfella <[email protected]>
Reported-by: Amit Goyal <[email protected]>
Cc: [email protected]
Reviewed-by: Eric Dumazet <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
anthraxx pushed a commit that referenced this pull request Sep 14, 2023
commit 2ea3528 upstream.

Commit bf5c25d ("skbuff: in skb_segment, call zerocopy functions
once per nskb") added the call to zero copy functions in skb_segment().
The change introduced a bug in skb_segment() because skb_orphan_frags()
may possibly change the number of fragments or allocate new fragments
altogether leaving nrfrags and frag to point to the old values. This can
cause a panic with stacktrace like the one below.

[  193.894380] BUG: kernel NULL pointer dereference, address: 00000000000000bc
[  193.895273] CPU: 13 PID: 18164 Comm: vh-net-17428 Kdump: loaded Tainted: G           O      5.15.123+ #26
[  193.903919] RIP: 0010:skb_segment+0xb0e/0x12f0
[  194.021892] Call Trace:
[  194.027422]  <TASK>
[  194.072861]  tcp_gso_segment+0x107/0x540
[  194.082031]  inet_gso_segment+0x15c/0x3d0
[  194.090783]  skb_mac_gso_segment+0x9f/0x110
[  194.095016]  __skb_gso_segment+0xc1/0x190
[  194.103131]  netem_enqueue+0x290/0xb10 [sch_netem]
[  194.107071]  dev_qdisc_enqueue+0x16/0x70
[  194.110884]  __dev_queue_xmit+0x63b/0xb30
[  194.121670]  bond_start_xmit+0x159/0x380 [bonding]
[  194.128506]  dev_hard_start_xmit+0xc3/0x1e0
[  194.131787]  __dev_queue_xmit+0x8a0/0xb30
[  194.138225]  macvlan_start_xmit+0x4f/0x100 [macvlan]
[  194.141477]  dev_hard_start_xmit+0xc3/0x1e0
[  194.144622]  sch_direct_xmit+0xe3/0x280
[  194.147748]  __dev_queue_xmit+0x54a/0xb30
[  194.154131]  tap_get_user+0x2a8/0x9c0 [tap]
[  194.157358]  tap_sendmsg+0x52/0x8e0 [tap]
[  194.167049]  handle_tx_zerocopy+0x14e/0x4c0 [vhost_net]
[  194.173631]  handle_tx+0xcd/0xe0 [vhost_net]
[  194.176959]  vhost_worker+0x76/0xb0 [vhost]
[  194.183667]  kthread+0x118/0x140
[  194.190358]  ret_from_fork+0x1f/0x30
[  194.193670]  </TASK>

In this case calling skb_orphan_frags() updated nr_frags leaving nrfrags
local variable in skb_segment() stale. This resulted in the code hitting
i >= nrfrags prematurely and trying to move to next frag_skb using
list_skb pointer, which was NULL, and caused kernel panic. Move the call
to zero copy functions before using frags and nr_frags.

Fixes: bf5c25d ("skbuff: in skb_segment, call zerocopy functions once per nskb")
Signed-off-by: Mohamed Khalfella <[email protected]>
Reported-by: Amit Goyal <[email protected]>
Cc: [email protected]
Reviewed-by: Eric Dumazet <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
anthraxx pushed a commit that referenced this pull request Sep 18, 2023
commit 2ea3528 upstream.

Commit bf5c25d ("skbuff: in skb_segment, call zerocopy functions
once per nskb") added the call to zero copy functions in skb_segment().
The change introduced a bug in skb_segment() because skb_orphan_frags()
may possibly change the number of fragments or allocate new fragments
altogether leaving nrfrags and frag to point to the old values. This can
cause a panic with stacktrace like the one below.

[  193.894380] BUG: kernel NULL pointer dereference, address: 00000000000000bc
[  193.895273] CPU: 13 PID: 18164 Comm: vh-net-17428 Kdump: loaded Tainted: G           O      5.15.123+ #26
[  193.903919] RIP: 0010:skb_segment+0xb0e/0x12f0
[  194.021892] Call Trace:
[  194.027422]  <TASK>
[  194.072861]  tcp_gso_segment+0x107/0x540
[  194.082031]  inet_gso_segment+0x15c/0x3d0
[  194.090783]  skb_mac_gso_segment+0x9f/0x110
[  194.095016]  __skb_gso_segment+0xc1/0x190
[  194.103131]  netem_enqueue+0x290/0xb10 [sch_netem]
[  194.107071]  dev_qdisc_enqueue+0x16/0x70
[  194.110884]  __dev_queue_xmit+0x63b/0xb30
[  194.121670]  bond_start_xmit+0x159/0x380 [bonding]
[  194.128506]  dev_hard_start_xmit+0xc3/0x1e0
[  194.131787]  __dev_queue_xmit+0x8a0/0xb30
[  194.138225]  macvlan_start_xmit+0x4f/0x100 [macvlan]
[  194.141477]  dev_hard_start_xmit+0xc3/0x1e0
[  194.144622]  sch_direct_xmit+0xe3/0x280
[  194.147748]  __dev_queue_xmit+0x54a/0xb30
[  194.154131]  tap_get_user+0x2a8/0x9c0 [tap]
[  194.157358]  tap_sendmsg+0x52/0x8e0 [tap]
[  194.167049]  handle_tx_zerocopy+0x14e/0x4c0 [vhost_net]
[  194.173631]  handle_tx+0xcd/0xe0 [vhost_net]
[  194.176959]  vhost_worker+0x76/0xb0 [vhost]
[  194.183667]  kthread+0x118/0x140
[  194.190358]  ret_from_fork+0x1f/0x30
[  194.193670]  </TASK>

In this case calling skb_orphan_frags() updated nr_frags leaving nrfrags
local variable in skb_segment() stale. This resulted in the code hitting
i >= nrfrags prematurely and trying to move to next frag_skb using
list_skb pointer, which was NULL, and caused kernel panic. Move the call
to zero copy functions before using frags and nr_frags.

Fixes: bf5c25d ("skbuff: in skb_segment, call zerocopy functions once per nskb")
Signed-off-by: Mohamed Khalfella <[email protected]>
Reported-by: Amit Goyal <[email protected]>
Cc: [email protected]
Reviewed-by: Eric Dumazet <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
anthraxx pushed a commit that referenced this pull request Sep 19, 2023
commit 2ea3528 upstream.

Commit bf5c25d ("skbuff: in skb_segment, call zerocopy functions
once per nskb") added the call to zero copy functions in skb_segment().
The change introduced a bug in skb_segment() because skb_orphan_frags()
may possibly change the number of fragments or allocate new fragments
altogether leaving nrfrags and frag to point to the old values. This can
cause a panic with stacktrace like the one below.

[  193.894380] BUG: kernel NULL pointer dereference, address: 00000000000000bc
[  193.895273] CPU: 13 PID: 18164 Comm: vh-net-17428 Kdump: loaded Tainted: G           O      5.15.123+ #26
[  193.903919] RIP: 0010:skb_segment+0xb0e/0x12f0
[  194.021892] Call Trace:
[  194.027422]  <TASK>
[  194.072861]  tcp_gso_segment+0x107/0x540
[  194.082031]  inet_gso_segment+0x15c/0x3d0
[  194.090783]  skb_mac_gso_segment+0x9f/0x110
[  194.095016]  __skb_gso_segment+0xc1/0x190
[  194.103131]  netem_enqueue+0x290/0xb10 [sch_netem]
[  194.107071]  dev_qdisc_enqueue+0x16/0x70
[  194.110884]  __dev_queue_xmit+0x63b/0xb30
[  194.121670]  bond_start_xmit+0x159/0x380 [bonding]
[  194.128506]  dev_hard_start_xmit+0xc3/0x1e0
[  194.131787]  __dev_queue_xmit+0x8a0/0xb30
[  194.138225]  macvlan_start_xmit+0x4f/0x100 [macvlan]
[  194.141477]  dev_hard_start_xmit+0xc3/0x1e0
[  194.144622]  sch_direct_xmit+0xe3/0x280
[  194.147748]  __dev_queue_xmit+0x54a/0xb30
[  194.154131]  tap_get_user+0x2a8/0x9c0 [tap]
[  194.157358]  tap_sendmsg+0x52/0x8e0 [tap]
[  194.167049]  handle_tx_zerocopy+0x14e/0x4c0 [vhost_net]
[  194.173631]  handle_tx+0xcd/0xe0 [vhost_net]
[  194.176959]  vhost_worker+0x76/0xb0 [vhost]
[  194.183667]  kthread+0x118/0x140
[  194.190358]  ret_from_fork+0x1f/0x30
[  194.193670]  </TASK>

In this case calling skb_orphan_frags() updated nr_frags leaving nrfrags
local variable in skb_segment() stale. This resulted in the code hitting
i >= nrfrags prematurely and trying to move to next frag_skb using
list_skb pointer, which was NULL, and caused kernel panic. Move the call
to zero copy functions before using frags and nr_frags.

Fixes: bf5c25d ("skbuff: in skb_segment, call zerocopy functions once per nskb")
Signed-off-by: Mohamed Khalfella <[email protected]>
Reported-by: Amit Goyal <[email protected]>
Cc: [email protected]
Reviewed-by: Eric Dumazet <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
anthraxx pushed a commit that referenced this pull request Sep 19, 2023
commit 2ea3528 upstream.

Commit bf5c25d ("skbuff: in skb_segment, call zerocopy functions
once per nskb") added the call to zero copy functions in skb_segment().
The change introduced a bug in skb_segment() because skb_orphan_frags()
may possibly change the number of fragments or allocate new fragments
altogether leaving nrfrags and frag to point to the old values. This can
cause a panic with stacktrace like the one below.

[  193.894380] BUG: kernel NULL pointer dereference, address: 00000000000000bc
[  193.895273] CPU: 13 PID: 18164 Comm: vh-net-17428 Kdump: loaded Tainted: G           O      5.15.123+ #26
[  193.903919] RIP: 0010:skb_segment+0xb0e/0x12f0
[  194.021892] Call Trace:
[  194.027422]  <TASK>
[  194.072861]  tcp_gso_segment+0x107/0x540
[  194.082031]  inet_gso_segment+0x15c/0x3d0
[  194.090783]  skb_mac_gso_segment+0x9f/0x110
[  194.095016]  __skb_gso_segment+0xc1/0x190
[  194.103131]  netem_enqueue+0x290/0xb10 [sch_netem]
[  194.107071]  dev_qdisc_enqueue+0x16/0x70
[  194.110884]  __dev_queue_xmit+0x63b/0xb30
[  194.121670]  bond_start_xmit+0x159/0x380 [bonding]
[  194.128506]  dev_hard_start_xmit+0xc3/0x1e0
[  194.131787]  __dev_queue_xmit+0x8a0/0xb30
[  194.138225]  macvlan_start_xmit+0x4f/0x100 [macvlan]
[  194.141477]  dev_hard_start_xmit+0xc3/0x1e0
[  194.144622]  sch_direct_xmit+0xe3/0x280
[  194.147748]  __dev_queue_xmit+0x54a/0xb30
[  194.154131]  tap_get_user+0x2a8/0x9c0 [tap]
[  194.157358]  tap_sendmsg+0x52/0x8e0 [tap]
[  194.167049]  handle_tx_zerocopy+0x14e/0x4c0 [vhost_net]
[  194.173631]  handle_tx+0xcd/0xe0 [vhost_net]
[  194.176959]  vhost_worker+0x76/0xb0 [vhost]
[  194.183667]  kthread+0x118/0x140
[  194.190358]  ret_from_fork+0x1f/0x30
[  194.193670]  </TASK>

In this case calling skb_orphan_frags() updated nr_frags leaving nrfrags
local variable in skb_segment() stale. This resulted in the code hitting
i >= nrfrags prematurely and trying to move to next frag_skb using
list_skb pointer, which was NULL, and caused kernel panic. Move the call
to zero copy functions before using frags and nr_frags.

Fixes: bf5c25d ("skbuff: in skb_segment, call zerocopy functions once per nskb")
Signed-off-by: Mohamed Khalfella <[email protected]>
Reported-by: Amit Goyal <[email protected]>
Cc: [email protected]
Reviewed-by: Eric Dumazet <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
anthraxx pushed a commit that referenced this pull request Sep 25, 2023
commit 2ea3528 upstream.

Commit bf5c25d ("skbuff: in skb_segment, call zerocopy functions
once per nskb") added the call to zero copy functions in skb_segment().
The change introduced a bug in skb_segment() because skb_orphan_frags()
may possibly change the number of fragments or allocate new fragments
altogether leaving nrfrags and frag to point to the old values. This can
cause a panic with stacktrace like the one below.

[  193.894380] BUG: kernel NULL pointer dereference, address: 00000000000000bc
[  193.895273] CPU: 13 PID: 18164 Comm: vh-net-17428 Kdump: loaded Tainted: G           O      5.15.123+ #26
[  193.903919] RIP: 0010:skb_segment+0xb0e/0x12f0
[  194.021892] Call Trace:
[  194.027422]  <TASK>
[  194.072861]  tcp_gso_segment+0x107/0x540
[  194.082031]  inet_gso_segment+0x15c/0x3d0
[  194.090783]  skb_mac_gso_segment+0x9f/0x110
[  194.095016]  __skb_gso_segment+0xc1/0x190
[  194.103131]  netem_enqueue+0x290/0xb10 [sch_netem]
[  194.107071]  dev_qdisc_enqueue+0x16/0x70
[  194.110884]  __dev_queue_xmit+0x63b/0xb30
[  194.121670]  bond_start_xmit+0x159/0x380 [bonding]
[  194.128506]  dev_hard_start_xmit+0xc3/0x1e0
[  194.131787]  __dev_queue_xmit+0x8a0/0xb30
[  194.138225]  macvlan_start_xmit+0x4f/0x100 [macvlan]
[  194.141477]  dev_hard_start_xmit+0xc3/0x1e0
[  194.144622]  sch_direct_xmit+0xe3/0x280
[  194.147748]  __dev_queue_xmit+0x54a/0xb30
[  194.154131]  tap_get_user+0x2a8/0x9c0 [tap]
[  194.157358]  tap_sendmsg+0x52/0x8e0 [tap]
[  194.167049]  handle_tx_zerocopy+0x14e/0x4c0 [vhost_net]
[  194.173631]  handle_tx+0xcd/0xe0 [vhost_net]
[  194.176959]  vhost_worker+0x76/0xb0 [vhost]
[  194.183667]  kthread+0x118/0x140
[  194.190358]  ret_from_fork+0x1f/0x30
[  194.193670]  </TASK>

In this case calling skb_orphan_frags() updated nr_frags leaving nrfrags
local variable in skb_segment() stale. This resulted in the code hitting
i >= nrfrags prematurely and trying to move to next frag_skb using
list_skb pointer, which was NULL, and caused kernel panic. Move the call
to zero copy functions before using frags and nr_frags.

Fixes: bf5c25d ("skbuff: in skb_segment, call zerocopy functions once per nskb")
Signed-off-by: Mohamed Khalfella <[email protected]>
Reported-by: Amit Goyal <[email protected]>
Cc: [email protected]
Reviewed-by: Eric Dumazet <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
anthraxx pushed a commit that referenced this pull request Sep 25, 2023
commit 2ea3528 upstream.

Commit bf5c25d ("skbuff: in skb_segment, call zerocopy functions
once per nskb") added the call to zero copy functions in skb_segment().
The change introduced a bug in skb_segment() because skb_orphan_frags()
may possibly change the number of fragments or allocate new fragments
altogether leaving nrfrags and frag to point to the old values. This can
cause a panic with stacktrace like the one below.

[  193.894380] BUG: kernel NULL pointer dereference, address: 00000000000000bc
[  193.895273] CPU: 13 PID: 18164 Comm: vh-net-17428 Kdump: loaded Tainted: G           O      5.15.123+ #26
[  193.903919] RIP: 0010:skb_segment+0xb0e/0x12f0
[  194.021892] Call Trace:
[  194.027422]  <TASK>
[  194.072861]  tcp_gso_segment+0x107/0x540
[  194.082031]  inet_gso_segment+0x15c/0x3d0
[  194.090783]  skb_mac_gso_segment+0x9f/0x110
[  194.095016]  __skb_gso_segment+0xc1/0x190
[  194.103131]  netem_enqueue+0x290/0xb10 [sch_netem]
[  194.107071]  dev_qdisc_enqueue+0x16/0x70
[  194.110884]  __dev_queue_xmit+0x63b/0xb30
[  194.121670]  bond_start_xmit+0x159/0x380 [bonding]
[  194.128506]  dev_hard_start_xmit+0xc3/0x1e0
[  194.131787]  __dev_queue_xmit+0x8a0/0xb30
[  194.138225]  macvlan_start_xmit+0x4f/0x100 [macvlan]
[  194.141477]  dev_hard_start_xmit+0xc3/0x1e0
[  194.144622]  sch_direct_xmit+0xe3/0x280
[  194.147748]  __dev_queue_xmit+0x54a/0xb30
[  194.154131]  tap_get_user+0x2a8/0x9c0 [tap]
[  194.157358]  tap_sendmsg+0x52/0x8e0 [tap]
[  194.167049]  handle_tx_zerocopy+0x14e/0x4c0 [vhost_net]
[  194.173631]  handle_tx+0xcd/0xe0 [vhost_net]
[  194.176959]  vhost_worker+0x76/0xb0 [vhost]
[  194.183667]  kthread+0x118/0x140
[  194.190358]  ret_from_fork+0x1f/0x30
[  194.193670]  </TASK>

In this case calling skb_orphan_frags() updated nr_frags leaving nrfrags
local variable in skb_segment() stale. This resulted in the code hitting
i >= nrfrags prematurely and trying to move to next frag_skb using
list_skb pointer, which was NULL, and caused kernel panic. Move the call
to zero copy functions before using frags and nr_frags.

Fixes: bf5c25d ("skbuff: in skb_segment, call zerocopy functions once per nskb")
Signed-off-by: Mohamed Khalfella <[email protected]>
Reported-by: Amit Goyal <[email protected]>
Cc: [email protected]
Reviewed-by: Eric Dumazet <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
anthraxx pushed a commit that referenced this pull request Sep 25, 2023
commit 0b0747d upstream.

The following processes run into a deadlock. CPU 41 was waiting for CPU 29
to handle a CSD request while holding spinlock "crashdump_lock", but CPU 29
was hung by that spinlock with IRQs disabled.

  PID: 17360    TASK: ffff95c1090c5c40  CPU: 41  COMMAND: "mrdiagd"
  !# 0 [ffffb80edbf37b58] __read_once_size at ffffffff9b871a40 include/linux/compiler.h:185:0
  !# 1 [ffffb80edbf37b58] atomic_read at ffffffff9b871a40 arch/x86/include/asm/atomic.h:27:0
  !# 2 [ffffb80edbf37b58] dump_stack at ffffffff9b871a40 lib/dump_stack.c:54:0
   # 3 [ffffb80edbf37b78] csd_lock_wait_toolong at ffffffff9b131ad5 kernel/smp.c:364:0
   # 4 [ffffb80edbf37b78] __csd_lock_wait at ffffffff9b131ad5 kernel/smp.c:384:0
   # 5 [ffffb80edbf37bf8] csd_lock_wait at ffffffff9b13267a kernel/smp.c:394:0
   # 6 [ffffb80edbf37bf8] smp_call_function_many at ffffffff9b13267a kernel/smp.c:843:0
   # 7 [ffffb80edbf37c50] smp_call_function at ffffffff9b13279d kernel/smp.c:867:0
   # 8 [ffffb80edbf37c50] on_each_cpu at ffffffff9b13279d kernel/smp.c:976:0
   # 9 [ffffb80edbf37c78] flush_tlb_kernel_range at ffffffff9b085c4b arch/x86/mm/tlb.c:742:0
   #10 [ffffb80edbf37cb8] __purge_vmap_area_lazy at ffffffff9b23a1e0 mm/vmalloc.c:701:0
   #11 [ffffb80edbf37ce0] try_purge_vmap_area_lazy at ffffffff9b23a2cc mm/vmalloc.c:722:0
   #12 [ffffb80edbf37ce0] free_vmap_area_noflush at ffffffff9b23a2cc mm/vmalloc.c:754:0
   #13 [ffffb80edbf37cf8] free_unmap_vmap_area at ffffffff9b23bb3b mm/vmalloc.c:764:0
   #14 [ffffb80edbf37cf8] remove_vm_area at ffffffff9b23bb3b mm/vmalloc.c:1509:0
   #15 [ffffb80edbf37d18] __vunmap at ffffffff9b23bb8a mm/vmalloc.c:1537:0
   #16 [ffffb80edbf37d40] vfree at ffffffff9b23bc85 mm/vmalloc.c:1612:0
   #17 [ffffb80edbf37d58] megasas_free_host_crash_buffer [megaraid_sas] at ffffffffc020b7f2 drivers/scsi/megaraid/megaraid_sas_fusion.c:3932:0
   #18 [ffffb80edbf37d80] fw_crash_state_store [megaraid_sas] at ffffffffc01f804d drivers/scsi/megaraid/megaraid_sas_base.c:3291:0
   #19 [ffffb80edbf37dc0] dev_attr_store at ffffffff9b56dd7b drivers/base/core.c:758:0
   #20 [ffffb80edbf37dd0] sysfs_kf_write at ffffffff9b326acf fs/sysfs/file.c:144:0
   #21 [ffffb80edbf37de0] kernfs_fop_write at ffffffff9b325fd4 fs/kernfs/file.c:316:0
   #22 [ffffb80edbf37e20] __vfs_write at ffffffff9b29418a fs/read_write.c:480:0
   #23 [ffffb80edbf37ea8] vfs_write at ffffffff9b294462 fs/read_write.c:544:0
   #24 [ffffb80edbf37ee8] SYSC_write at ffffffff9b2946ec fs/read_write.c:590:0
   #25 [ffffb80edbf37ee8] SyS_write at ffffffff9b2946ec fs/read_write.c:582:0
   #26 [ffffb80edbf37f30] do_syscall_64 at ffffffff9b003ca9 arch/x86/entry/common.c:298:0
   #27 [ffffb80edbf37f58] entry_SYSCALL_64 at ffffffff9ba001b1 arch/x86/entry/entry_64.S:238:0

  PID: 17355    TASK: ffff95c1090c3d80  CPU: 29  COMMAND: "mrdiagd"
  !# 0 [ffffb80f2d3c7d30] __read_once_size at ffffffff9b0f2ab0 include/linux/compiler.h:185:0
  !# 1 [ffffb80f2d3c7d30] native_queued_spin_lock_slowpath at ffffffff9b0f2ab0 kernel/locking/qspinlock.c:368:0
   # 2 [ffffb80f2d3c7d58] pv_queued_spin_lock_slowpath at ffffffff9b0f244b arch/x86/include/asm/paravirt.h:674:0
   # 3 [ffffb80f2d3c7d58] queued_spin_lock_slowpath at ffffffff9b0f244b arch/x86/include/asm/qspinlock.h:53:0
   # 4 [ffffb80f2d3c7d68] queued_spin_lock at ffffffff9b8961a6 include/asm-generic/qspinlock.h:90:0
   # 5 [ffffb80f2d3c7d68] do_raw_spin_lock_flags at ffffffff9b8961a6 include/linux/spinlock.h:173:0
   # 6 [ffffb80f2d3c7d68] __raw_spin_lock_irqsave at ffffffff9b8961a6 include/linux/spinlock_api_smp.h:122:0
   # 7 [ffffb80f2d3c7d68] _raw_spin_lock_irqsave at ffffffff9b8961a6 kernel/locking/spinlock.c:160:0
   # 8 [ffffb80f2d3c7d88] fw_crash_buffer_store [megaraid_sas] at ffffffffc01f8129 drivers/scsi/megaraid/megaraid_sas_base.c:3205:0
   # 9 [ffffb80f2d3c7dc0] dev_attr_store at ffffffff9b56dd7b drivers/base/core.c:758:0
   #10 [ffffb80f2d3c7dd0] sysfs_kf_write at ffffffff9b326acf fs/sysfs/file.c:144:0
   #11 [ffffb80f2d3c7de0] kernfs_fop_write at ffffffff9b325fd4 fs/kernfs/file.c:316:0
   #12 [ffffb80f2d3c7e20] __vfs_write at ffffffff9b29418a fs/read_write.c:480:0
   #13 [ffffb80f2d3c7ea8] vfs_write at ffffffff9b294462 fs/read_write.c:544:0
   #14 [ffffb80f2d3c7ee8] SYSC_write at ffffffff9b2946ec fs/read_write.c:590:0
   #15 [ffffb80f2d3c7ee8] SyS_write at ffffffff9b2946ec fs/read_write.c:582:0
   #16 [ffffb80f2d3c7f30] do_syscall_64 at ffffffff9b003ca9 arch/x86/entry/common.c:298:0
   #17 [ffffb80f2d3c7f58] entry_SYSCALL_64 at ffffffff9ba001b1 arch/x86/entry/entry_64.S:238:0

The lock is used to synchronize different sysfs operations, it doesn't
protect any resource that will be touched by an interrupt. Consequently
it's not required to disable IRQs. Replace the spinlock with a mutex to fix
the deadlock.

Signed-off-by: Junxiao Bi <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Mike Christie <[email protected]>
Cc: [email protected]
Signed-off-by: Martin K. Petersen <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
anthraxx pushed a commit that referenced this pull request Sep 25, 2023
commit 0b0747d upstream.

The following processes run into a deadlock. CPU 41 was waiting for CPU 29
to handle a CSD request while holding spinlock "crashdump_lock", but CPU 29
was hung by that spinlock with IRQs disabled.

  PID: 17360    TASK: ffff95c1090c5c40  CPU: 41  COMMAND: "mrdiagd"
  !# 0 [ffffb80edbf37b58] __read_once_size at ffffffff9b871a40 include/linux/compiler.h:185:0
  !# 1 [ffffb80edbf37b58] atomic_read at ffffffff9b871a40 arch/x86/include/asm/atomic.h:27:0
  !# 2 [ffffb80edbf37b58] dump_stack at ffffffff9b871a40 lib/dump_stack.c:54:0
   # 3 [ffffb80edbf37b78] csd_lock_wait_toolong at ffffffff9b131ad5 kernel/smp.c:364:0
   # 4 [ffffb80edbf37b78] __csd_lock_wait at ffffffff9b131ad5 kernel/smp.c:384:0
   # 5 [ffffb80edbf37bf8] csd_lock_wait at ffffffff9b13267a kernel/smp.c:394:0
   # 6 [ffffb80edbf37bf8] smp_call_function_many at ffffffff9b13267a kernel/smp.c:843:0
   # 7 [ffffb80edbf37c50] smp_call_function at ffffffff9b13279d kernel/smp.c:867:0
   # 8 [ffffb80edbf37c50] on_each_cpu at ffffffff9b13279d kernel/smp.c:976:0
   # 9 [ffffb80edbf37c78] flush_tlb_kernel_range at ffffffff9b085c4b arch/x86/mm/tlb.c:742:0
   #10 [ffffb80edbf37cb8] __purge_vmap_area_lazy at ffffffff9b23a1e0 mm/vmalloc.c:701:0
   #11 [ffffb80edbf37ce0] try_purge_vmap_area_lazy at ffffffff9b23a2cc mm/vmalloc.c:722:0
   #12 [ffffb80edbf37ce0] free_vmap_area_noflush at ffffffff9b23a2cc mm/vmalloc.c:754:0
   #13 [ffffb80edbf37cf8] free_unmap_vmap_area at ffffffff9b23bb3b mm/vmalloc.c:764:0
   #14 [ffffb80edbf37cf8] remove_vm_area at ffffffff9b23bb3b mm/vmalloc.c:1509:0
   #15 [ffffb80edbf37d18] __vunmap at ffffffff9b23bb8a mm/vmalloc.c:1537:0
   #16 [ffffb80edbf37d40] vfree at ffffffff9b23bc85 mm/vmalloc.c:1612:0
   #17 [ffffb80edbf37d58] megasas_free_host_crash_buffer [megaraid_sas] at ffffffffc020b7f2 drivers/scsi/megaraid/megaraid_sas_fusion.c:3932:0
   #18 [ffffb80edbf37d80] fw_crash_state_store [megaraid_sas] at ffffffffc01f804d drivers/scsi/megaraid/megaraid_sas_base.c:3291:0
   #19 [ffffb80edbf37dc0] dev_attr_store at ffffffff9b56dd7b drivers/base/core.c:758:0
   #20 [ffffb80edbf37dd0] sysfs_kf_write at ffffffff9b326acf fs/sysfs/file.c:144:0
   #21 [ffffb80edbf37de0] kernfs_fop_write at ffffffff9b325fd4 fs/kernfs/file.c:316:0
   #22 [ffffb80edbf37e20] __vfs_write at ffffffff9b29418a fs/read_write.c:480:0
   #23 [ffffb80edbf37ea8] vfs_write at ffffffff9b294462 fs/read_write.c:544:0
   #24 [ffffb80edbf37ee8] SYSC_write at ffffffff9b2946ec fs/read_write.c:590:0
   #25 [ffffb80edbf37ee8] SyS_write at ffffffff9b2946ec fs/read_write.c:582:0
   #26 [ffffb80edbf37f30] do_syscall_64 at ffffffff9b003ca9 arch/x86/entry/common.c:298:0
   #27 [ffffb80edbf37f58] entry_SYSCALL_64 at ffffffff9ba001b1 arch/x86/entry/entry_64.S:238:0

  PID: 17355    TASK: ffff95c1090c3d80  CPU: 29  COMMAND: "mrdiagd"
  !# 0 [ffffb80f2d3c7d30] __read_once_size at ffffffff9b0f2ab0 include/linux/compiler.h:185:0
  !# 1 [ffffb80f2d3c7d30] native_queued_spin_lock_slowpath at ffffffff9b0f2ab0 kernel/locking/qspinlock.c:368:0
   # 2 [ffffb80f2d3c7d58] pv_queued_spin_lock_slowpath at ffffffff9b0f244b arch/x86/include/asm/paravirt.h:674:0
   # 3 [ffffb80f2d3c7d58] queued_spin_lock_slowpath at ffffffff9b0f244b arch/x86/include/asm/qspinlock.h:53:0
   # 4 [ffffb80f2d3c7d68] queued_spin_lock at ffffffff9b8961a6 include/asm-generic/qspinlock.h:90:0
   # 5 [ffffb80f2d3c7d68] do_raw_spin_lock_flags at ffffffff9b8961a6 include/linux/spinlock.h:173:0
   # 6 [ffffb80f2d3c7d68] __raw_spin_lock_irqsave at ffffffff9b8961a6 include/linux/spinlock_api_smp.h:122:0
   # 7 [ffffb80f2d3c7d68] _raw_spin_lock_irqsave at ffffffff9b8961a6 kernel/locking/spinlock.c:160:0
   # 8 [ffffb80f2d3c7d88] fw_crash_buffer_store [megaraid_sas] at ffffffffc01f8129 drivers/scsi/megaraid/megaraid_sas_base.c:3205:0
   # 9 [ffffb80f2d3c7dc0] dev_attr_store at ffffffff9b56dd7b drivers/base/core.c:758:0
   #10 [ffffb80f2d3c7dd0] sysfs_kf_write at ffffffff9b326acf fs/sysfs/file.c:144:0
   #11 [ffffb80f2d3c7de0] kernfs_fop_write at ffffffff9b325fd4 fs/kernfs/file.c:316:0
   #12 [ffffb80f2d3c7e20] __vfs_write at ffffffff9b29418a fs/read_write.c:480:0
   #13 [ffffb80f2d3c7ea8] vfs_write at ffffffff9b294462 fs/read_write.c:544:0
   #14 [ffffb80f2d3c7ee8] SYSC_write at ffffffff9b2946ec fs/read_write.c:590:0
   #15 [ffffb80f2d3c7ee8] SyS_write at ffffffff9b2946ec fs/read_write.c:582:0
   #16 [ffffb80f2d3c7f30] do_syscall_64 at ffffffff9b003ca9 arch/x86/entry/common.c:298:0
   #17 [ffffb80f2d3c7f58] entry_SYSCALL_64 at ffffffff9ba001b1 arch/x86/entry/entry_64.S:238:0

The lock is used to synchronize different sysfs operations, it doesn't
protect any resource that will be touched by an interrupt. Consequently
it's not required to disable IRQs. Replace the spinlock with a mutex to fix
the deadlock.

Signed-off-by: Junxiao Bi <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Mike Christie <[email protected]>
Cc: [email protected]
Signed-off-by: Martin K. Petersen <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
anthraxx pushed a commit that referenced this pull request Sep 25, 2023
commit 0b0747d upstream.

The following processes run into a deadlock. CPU 41 was waiting for CPU 29
to handle a CSD request while holding spinlock "crashdump_lock", but CPU 29
was hung by that spinlock with IRQs disabled.

  PID: 17360    TASK: ffff95c1090c5c40  CPU: 41  COMMAND: "mrdiagd"
  !# 0 [ffffb80edbf37b58] __read_once_size at ffffffff9b871a40 include/linux/compiler.h:185:0
  !# 1 [ffffb80edbf37b58] atomic_read at ffffffff9b871a40 arch/x86/include/asm/atomic.h:27:0
  !# 2 [ffffb80edbf37b58] dump_stack at ffffffff9b871a40 lib/dump_stack.c:54:0
   # 3 [ffffb80edbf37b78] csd_lock_wait_toolong at ffffffff9b131ad5 kernel/smp.c:364:0
   # 4 [ffffb80edbf37b78] __csd_lock_wait at ffffffff9b131ad5 kernel/smp.c:384:0
   # 5 [ffffb80edbf37bf8] csd_lock_wait at ffffffff9b13267a kernel/smp.c:394:0
   # 6 [ffffb80edbf37bf8] smp_call_function_many at ffffffff9b13267a kernel/smp.c:843:0
   # 7 [ffffb80edbf37c50] smp_call_function at ffffffff9b13279d kernel/smp.c:867:0
   # 8 [ffffb80edbf37c50] on_each_cpu at ffffffff9b13279d kernel/smp.c:976:0
   # 9 [ffffb80edbf37c78] flush_tlb_kernel_range at ffffffff9b085c4b arch/x86/mm/tlb.c:742:0
   #10 [ffffb80edbf37cb8] __purge_vmap_area_lazy at ffffffff9b23a1e0 mm/vmalloc.c:701:0
   #11 [ffffb80edbf37ce0] try_purge_vmap_area_lazy at ffffffff9b23a2cc mm/vmalloc.c:722:0
   #12 [ffffb80edbf37ce0] free_vmap_area_noflush at ffffffff9b23a2cc mm/vmalloc.c:754:0
   #13 [ffffb80edbf37cf8] free_unmap_vmap_area at ffffffff9b23bb3b mm/vmalloc.c:764:0
   #14 [ffffb80edbf37cf8] remove_vm_area at ffffffff9b23bb3b mm/vmalloc.c:1509:0
   #15 [ffffb80edbf37d18] __vunmap at ffffffff9b23bb8a mm/vmalloc.c:1537:0
   #16 [ffffb80edbf37d40] vfree at ffffffff9b23bc85 mm/vmalloc.c:1612:0
   #17 [ffffb80edbf37d58] megasas_free_host_crash_buffer [megaraid_sas] at ffffffffc020b7f2 drivers/scsi/megaraid/megaraid_sas_fusion.c:3932:0
   #18 [ffffb80edbf37d80] fw_crash_state_store [megaraid_sas] at ffffffffc01f804d drivers/scsi/megaraid/megaraid_sas_base.c:3291:0
   #19 [ffffb80edbf37dc0] dev_attr_store at ffffffff9b56dd7b drivers/base/core.c:758:0
   #20 [ffffb80edbf37dd0] sysfs_kf_write at ffffffff9b326acf fs/sysfs/file.c:144:0
   #21 [ffffb80edbf37de0] kernfs_fop_write at ffffffff9b325fd4 fs/kernfs/file.c:316:0
   #22 [ffffb80edbf37e20] __vfs_write at ffffffff9b29418a fs/read_write.c:480:0
   #23 [ffffb80edbf37ea8] vfs_write at ffffffff9b294462 fs/read_write.c:544:0
   #24 [ffffb80edbf37ee8] SYSC_write at ffffffff9b2946ec fs/read_write.c:590:0
   #25 [ffffb80edbf37ee8] SyS_write at ffffffff9b2946ec fs/read_write.c:582:0
   #26 [ffffb80edbf37f30] do_syscall_64 at ffffffff9b003ca9 arch/x86/entry/common.c:298:0
   #27 [ffffb80edbf37f58] entry_SYSCALL_64 at ffffffff9ba001b1 arch/x86/entry/entry_64.S:238:0

  PID: 17355    TASK: ffff95c1090c3d80  CPU: 29  COMMAND: "mrdiagd"
  !# 0 [ffffb80f2d3c7d30] __read_once_size at ffffffff9b0f2ab0 include/linux/compiler.h:185:0
  !# 1 [ffffb80f2d3c7d30] native_queued_spin_lock_slowpath at ffffffff9b0f2ab0 kernel/locking/qspinlock.c:368:0
   # 2 [ffffb80f2d3c7d58] pv_queued_spin_lock_slowpath at ffffffff9b0f244b arch/x86/include/asm/paravirt.h:674:0
   # 3 [ffffb80f2d3c7d58] queued_spin_lock_slowpath at ffffffff9b0f244b arch/x86/include/asm/qspinlock.h:53:0
   # 4 [ffffb80f2d3c7d68] queued_spin_lock at ffffffff9b8961a6 include/asm-generic/qspinlock.h:90:0
   # 5 [ffffb80f2d3c7d68] do_raw_spin_lock_flags at ffffffff9b8961a6 include/linux/spinlock.h:173:0
   # 6 [ffffb80f2d3c7d68] __raw_spin_lock_irqsave at ffffffff9b8961a6 include/linux/spinlock_api_smp.h:122:0
   # 7 [ffffb80f2d3c7d68] _raw_spin_lock_irqsave at ffffffff9b8961a6 kernel/locking/spinlock.c:160:0
   # 8 [ffffb80f2d3c7d88] fw_crash_buffer_store [megaraid_sas] at ffffffffc01f8129 drivers/scsi/megaraid/megaraid_sas_base.c:3205:0
   # 9 [ffffb80f2d3c7dc0] dev_attr_store at ffffffff9b56dd7b drivers/base/core.c:758:0
   #10 [ffffb80f2d3c7dd0] sysfs_kf_write at ffffffff9b326acf fs/sysfs/file.c:144:0
   #11 [ffffb80f2d3c7de0] kernfs_fop_write at ffffffff9b325fd4 fs/kernfs/file.c:316:0
   #12 [ffffb80f2d3c7e20] __vfs_write at ffffffff9b29418a fs/read_write.c:480:0
   #13 [ffffb80f2d3c7ea8] vfs_write at ffffffff9b294462 fs/read_write.c:544:0
   #14 [ffffb80f2d3c7ee8] SYSC_write at ffffffff9b2946ec fs/read_write.c:590:0
   #15 [ffffb80f2d3c7ee8] SyS_write at ffffffff9b2946ec fs/read_write.c:582:0
   #16 [ffffb80f2d3c7f30] do_syscall_64 at ffffffff9b003ca9 arch/x86/entry/common.c:298:0
   #17 [ffffb80f2d3c7f58] entry_SYSCALL_64 at ffffffff9ba001b1 arch/x86/entry/entry_64.S:238:0

The lock is used to synchronize different sysfs operations, it doesn't
protect any resource that will be touched by an interrupt. Consequently
it's not required to disable IRQs. Replace the spinlock with a mutex to fix
the deadlock.

Signed-off-by: Junxiao Bi <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Mike Christie <[email protected]>
Cc: [email protected]
Signed-off-by: Martin K. Petersen <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
anthraxx pushed a commit that referenced this pull request Sep 25, 2023
commit 0b0747d upstream.

The following processes run into a deadlock. CPU 41 was waiting for CPU 29
to handle a CSD request while holding spinlock "crashdump_lock", but CPU 29
was hung by that spinlock with IRQs disabled.

  PID: 17360    TASK: ffff95c1090c5c40  CPU: 41  COMMAND: "mrdiagd"
  !# 0 [ffffb80edbf37b58] __read_once_size at ffffffff9b871a40 include/linux/compiler.h:185:0
  !# 1 [ffffb80edbf37b58] atomic_read at ffffffff9b871a40 arch/x86/include/asm/atomic.h:27:0
  !# 2 [ffffb80edbf37b58] dump_stack at ffffffff9b871a40 lib/dump_stack.c:54:0
   # 3 [ffffb80edbf37b78] csd_lock_wait_toolong at ffffffff9b131ad5 kernel/smp.c:364:0
   # 4 [ffffb80edbf37b78] __csd_lock_wait at ffffffff9b131ad5 kernel/smp.c:384:0
   # 5 [ffffb80edbf37bf8] csd_lock_wait at ffffffff9b13267a kernel/smp.c:394:0
   # 6 [ffffb80edbf37bf8] smp_call_function_many at ffffffff9b13267a kernel/smp.c:843:0
   # 7 [ffffb80edbf37c50] smp_call_function at ffffffff9b13279d kernel/smp.c:867:0
   # 8 [ffffb80edbf37c50] on_each_cpu at ffffffff9b13279d kernel/smp.c:976:0
   # 9 [ffffb80edbf37c78] flush_tlb_kernel_range at ffffffff9b085c4b arch/x86/mm/tlb.c:742:0
   #10 [ffffb80edbf37cb8] __purge_vmap_area_lazy at ffffffff9b23a1e0 mm/vmalloc.c:701:0
   #11 [ffffb80edbf37ce0] try_purge_vmap_area_lazy at ffffffff9b23a2cc mm/vmalloc.c:722:0
   #12 [ffffb80edbf37ce0] free_vmap_area_noflush at ffffffff9b23a2cc mm/vmalloc.c:754:0
   #13 [ffffb80edbf37cf8] free_unmap_vmap_area at ffffffff9b23bb3b mm/vmalloc.c:764:0
   #14 [ffffb80edbf37cf8] remove_vm_area at ffffffff9b23bb3b mm/vmalloc.c:1509:0
   #15 [ffffb80edbf37d18] __vunmap at ffffffff9b23bb8a mm/vmalloc.c:1537:0
   #16 [ffffb80edbf37d40] vfree at ffffffff9b23bc85 mm/vmalloc.c:1612:0
   #17 [ffffb80edbf37d58] megasas_free_host_crash_buffer [megaraid_sas] at ffffffffc020b7f2 drivers/scsi/megaraid/megaraid_sas_fusion.c:3932:0
   #18 [ffffb80edbf37d80] fw_crash_state_store [megaraid_sas] at ffffffffc01f804d drivers/scsi/megaraid/megaraid_sas_base.c:3291:0
   #19 [ffffb80edbf37dc0] dev_attr_store at ffffffff9b56dd7b drivers/base/core.c:758:0
   #20 [ffffb80edbf37dd0] sysfs_kf_write at ffffffff9b326acf fs/sysfs/file.c:144:0
   #21 [ffffb80edbf37de0] kernfs_fop_write at ffffffff9b325fd4 fs/kernfs/file.c:316:0
   #22 [ffffb80edbf37e20] __vfs_write at ffffffff9b29418a fs/read_write.c:480:0
   #23 [ffffb80edbf37ea8] vfs_write at ffffffff9b294462 fs/read_write.c:544:0
   #24 [ffffb80edbf37ee8] SYSC_write at ffffffff9b2946ec fs/read_write.c:590:0
   #25 [ffffb80edbf37ee8] SyS_write at ffffffff9b2946ec fs/read_write.c:582:0
   #26 [ffffb80edbf37f30] do_syscall_64 at ffffffff9b003ca9 arch/x86/entry/common.c:298:0
   #27 [ffffb80edbf37f58] entry_SYSCALL_64 at ffffffff9ba001b1 arch/x86/entry/entry_64.S:238:0

  PID: 17355    TASK: ffff95c1090c3d80  CPU: 29  COMMAND: "mrdiagd"
  !# 0 [ffffb80f2d3c7d30] __read_once_size at ffffffff9b0f2ab0 include/linux/compiler.h:185:0
  !# 1 [ffffb80f2d3c7d30] native_queued_spin_lock_slowpath at ffffffff9b0f2ab0 kernel/locking/qspinlock.c:368:0
   # 2 [ffffb80f2d3c7d58] pv_queued_spin_lock_slowpath at ffffffff9b0f244b arch/x86/include/asm/paravirt.h:674:0
   # 3 [ffffb80f2d3c7d58] queued_spin_lock_slowpath at ffffffff9b0f244b arch/x86/include/asm/qspinlock.h:53:0
   # 4 [ffffb80f2d3c7d68] queued_spin_lock at ffffffff9b8961a6 include/asm-generic/qspinlock.h:90:0
   # 5 [ffffb80f2d3c7d68] do_raw_spin_lock_flags at ffffffff9b8961a6 include/linux/spinlock.h:173:0
   # 6 [ffffb80f2d3c7d68] __raw_spin_lock_irqsave at ffffffff9b8961a6 include/linux/spinlock_api_smp.h:122:0
   # 7 [ffffb80f2d3c7d68] _raw_spin_lock_irqsave at ffffffff9b8961a6 kernel/locking/spinlock.c:160:0
   # 8 [ffffb80f2d3c7d88] fw_crash_buffer_store [megaraid_sas] at ffffffffc01f8129 drivers/scsi/megaraid/megaraid_sas_base.c:3205:0
   # 9 [ffffb80f2d3c7dc0] dev_attr_store at ffffffff9b56dd7b drivers/base/core.c:758:0
   #10 [ffffb80f2d3c7dd0] sysfs_kf_write at ffffffff9b326acf fs/sysfs/file.c:144:0
   #11 [ffffb80f2d3c7de0] kernfs_fop_write at ffffffff9b325fd4 fs/kernfs/file.c:316:0
   #12 [ffffb80f2d3c7e20] __vfs_write at ffffffff9b29418a fs/read_write.c:480:0
   #13 [ffffb80f2d3c7ea8] vfs_write at ffffffff9b294462 fs/read_write.c:544:0
   #14 [ffffb80f2d3c7ee8] SYSC_write at ffffffff9b2946ec fs/read_write.c:590:0
   #15 [ffffb80f2d3c7ee8] SyS_write at ffffffff9b2946ec fs/read_write.c:582:0
   #16 [ffffb80f2d3c7f30] do_syscall_64 at ffffffff9b003ca9 arch/x86/entry/common.c:298:0
   #17 [ffffb80f2d3c7f58] entry_SYSCALL_64 at ffffffff9ba001b1 arch/x86/entry/entry_64.S:238:0

The lock is used to synchronize different sysfs operations, it doesn't
protect any resource that will be touched by an interrupt. Consequently
it's not required to disable IRQs. Replace the spinlock with a mutex to fix
the deadlock.

Signed-off-by: Junxiao Bi <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Mike Christie <[email protected]>
Cc: [email protected]
Signed-off-by: Martin K. Petersen <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
anthraxx pushed a commit that referenced this pull request Sep 25, 2023
commit 0b0747d upstream.

The following processes run into a deadlock. CPU 41 was waiting for CPU 29
to handle a CSD request while holding spinlock "crashdump_lock", but CPU 29
was hung by that spinlock with IRQs disabled.

  PID: 17360    TASK: ffff95c1090c5c40  CPU: 41  COMMAND: "mrdiagd"
  !# 0 [ffffb80edbf37b58] __read_once_size at ffffffff9b871a40 include/linux/compiler.h:185:0
  !# 1 [ffffb80edbf37b58] atomic_read at ffffffff9b871a40 arch/x86/include/asm/atomic.h:27:0
  !# 2 [ffffb80edbf37b58] dump_stack at ffffffff9b871a40 lib/dump_stack.c:54:0
   # 3 [ffffb80edbf37b78] csd_lock_wait_toolong at ffffffff9b131ad5 kernel/smp.c:364:0
   # 4 [ffffb80edbf37b78] __csd_lock_wait at ffffffff9b131ad5 kernel/smp.c:384:0
   # 5 [ffffb80edbf37bf8] csd_lock_wait at ffffffff9b13267a kernel/smp.c:394:0
   # 6 [ffffb80edbf37bf8] smp_call_function_many at ffffffff9b13267a kernel/smp.c:843:0
   # 7 [ffffb80edbf37c50] smp_call_function at ffffffff9b13279d kernel/smp.c:867:0
   # 8 [ffffb80edbf37c50] on_each_cpu at ffffffff9b13279d kernel/smp.c:976:0
   # 9 [ffffb80edbf37c78] flush_tlb_kernel_range at ffffffff9b085c4b arch/x86/mm/tlb.c:742:0
   #10 [ffffb80edbf37cb8] __purge_vmap_area_lazy at ffffffff9b23a1e0 mm/vmalloc.c:701:0
   #11 [ffffb80edbf37ce0] try_purge_vmap_area_lazy at ffffffff9b23a2cc mm/vmalloc.c:722:0
   #12 [ffffb80edbf37ce0] free_vmap_area_noflush at ffffffff9b23a2cc mm/vmalloc.c:754:0
   #13 [ffffb80edbf37cf8] free_unmap_vmap_area at ffffffff9b23bb3b mm/vmalloc.c:764:0
   #14 [ffffb80edbf37cf8] remove_vm_area at ffffffff9b23bb3b mm/vmalloc.c:1509:0
   #15 [ffffb80edbf37d18] __vunmap at ffffffff9b23bb8a mm/vmalloc.c:1537:0
   #16 [ffffb80edbf37d40] vfree at ffffffff9b23bc85 mm/vmalloc.c:1612:0
   #17 [ffffb80edbf37d58] megasas_free_host_crash_buffer [megaraid_sas] at ffffffffc020b7f2 drivers/scsi/megaraid/megaraid_sas_fusion.c:3932:0
   #18 [ffffb80edbf37d80] fw_crash_state_store [megaraid_sas] at ffffffffc01f804d drivers/scsi/megaraid/megaraid_sas_base.c:3291:0
   #19 [ffffb80edbf37dc0] dev_attr_store at ffffffff9b56dd7b drivers/base/core.c:758:0
   #20 [ffffb80edbf37dd0] sysfs_kf_write at ffffffff9b326acf fs/sysfs/file.c:144:0
   #21 [ffffb80edbf37de0] kernfs_fop_write at ffffffff9b325fd4 fs/kernfs/file.c:316:0
   #22 [ffffb80edbf37e20] __vfs_write at ffffffff9b29418a fs/read_write.c:480:0
   #23 [ffffb80edbf37ea8] vfs_write at ffffffff9b294462 fs/read_write.c:544:0
   #24 [ffffb80edbf37ee8] SYSC_write at ffffffff9b2946ec fs/read_write.c:590:0
   #25 [ffffb80edbf37ee8] SyS_write at ffffffff9b2946ec fs/read_write.c:582:0
   #26 [ffffb80edbf37f30] do_syscall_64 at ffffffff9b003ca9 arch/x86/entry/common.c:298:0
   #27 [ffffb80edbf37f58] entry_SYSCALL_64 at ffffffff9ba001b1 arch/x86/entry/entry_64.S:238:0

  PID: 17355    TASK: ffff95c1090c3d80  CPU: 29  COMMAND: "mrdiagd"
  !# 0 [ffffb80f2d3c7d30] __read_once_size at ffffffff9b0f2ab0 include/linux/compiler.h:185:0
  !# 1 [ffffb80f2d3c7d30] native_queued_spin_lock_slowpath at ffffffff9b0f2ab0 kernel/locking/qspinlock.c:368:0
   # 2 [ffffb80f2d3c7d58] pv_queued_spin_lock_slowpath at ffffffff9b0f244b arch/x86/include/asm/paravirt.h:674:0
   # 3 [ffffb80f2d3c7d58] queued_spin_lock_slowpath at ffffffff9b0f244b arch/x86/include/asm/qspinlock.h:53:0
   # 4 [ffffb80f2d3c7d68] queued_spin_lock at ffffffff9b8961a6 include/asm-generic/qspinlock.h:90:0
   # 5 [ffffb80f2d3c7d68] do_raw_spin_lock_flags at ffffffff9b8961a6 include/linux/spinlock.h:173:0
   # 6 [ffffb80f2d3c7d68] __raw_spin_lock_irqsave at ffffffff9b8961a6 include/linux/spinlock_api_smp.h:122:0
   # 7 [ffffb80f2d3c7d68] _raw_spin_lock_irqsave at ffffffff9b8961a6 kernel/locking/spinlock.c:160:0
   # 8 [ffffb80f2d3c7d88] fw_crash_buffer_store [megaraid_sas] at ffffffffc01f8129 drivers/scsi/megaraid/megaraid_sas_base.c:3205:0
   # 9 [ffffb80f2d3c7dc0] dev_attr_store at ffffffff9b56dd7b drivers/base/core.c:758:0
   #10 [ffffb80f2d3c7dd0] sysfs_kf_write at ffffffff9b326acf fs/sysfs/file.c:144:0
   #11 [ffffb80f2d3c7de0] kernfs_fop_write at ffffffff9b325fd4 fs/kernfs/file.c:316:0
   #12 [ffffb80f2d3c7e20] __vfs_write at ffffffff9b29418a fs/read_write.c:480:0
   #13 [ffffb80f2d3c7ea8] vfs_write at ffffffff9b294462 fs/read_write.c:544:0
   #14 [ffffb80f2d3c7ee8] SYSC_write at ffffffff9b2946ec fs/read_write.c:590:0
   #15 [ffffb80f2d3c7ee8] SyS_write at ffffffff9b2946ec fs/read_write.c:582:0
   #16 [ffffb80f2d3c7f30] do_syscall_64 at ffffffff9b003ca9 arch/x86/entry/common.c:298:0
   #17 [ffffb80f2d3c7f58] entry_SYSCALL_64 at ffffffff9ba001b1 arch/x86/entry/entry_64.S:238:0

The lock is used to synchronize different sysfs operations, it doesn't
protect any resource that will be touched by an interrupt. Consequently
it's not required to disable IRQs. Replace the spinlock with a mutex to fix
the deadlock.

Signed-off-by: Junxiao Bi <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Mike Christie <[email protected]>
Cc: [email protected]
Signed-off-by: Martin K. Petersen <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
anthraxx pushed a commit that referenced this pull request Oct 11, 2023
[ Upstream commit 0b0747d ]

The following processes run into a deadlock. CPU 41 was waiting for CPU 29
to handle a CSD request while holding spinlock "crashdump_lock", but CPU 29
was hung by that spinlock with IRQs disabled.

  PID: 17360    TASK: ffff95c1090c5c40  CPU: 41  COMMAND: "mrdiagd"
  !# 0 [ffffb80edbf37b58] __read_once_size at ffffffff9b871a40 include/linux/compiler.h:185:0
  !# 1 [ffffb80edbf37b58] atomic_read at ffffffff9b871a40 arch/x86/include/asm/atomic.h:27:0
  !# 2 [ffffb80edbf37b58] dump_stack at ffffffff9b871a40 lib/dump_stack.c:54:0
   # 3 [ffffb80edbf37b78] csd_lock_wait_toolong at ffffffff9b131ad5 kernel/smp.c:364:0
   # 4 [ffffb80edbf37b78] __csd_lock_wait at ffffffff9b131ad5 kernel/smp.c:384:0
   # 5 [ffffb80edbf37bf8] csd_lock_wait at ffffffff9b13267a kernel/smp.c:394:0
   # 6 [ffffb80edbf37bf8] smp_call_function_many at ffffffff9b13267a kernel/smp.c:843:0
   # 7 [ffffb80edbf37c50] smp_call_function at ffffffff9b13279d kernel/smp.c:867:0
   # 8 [ffffb80edbf37c50] on_each_cpu at ffffffff9b13279d kernel/smp.c:976:0
   # 9 [ffffb80edbf37c78] flush_tlb_kernel_range at ffffffff9b085c4b arch/x86/mm/tlb.c:742:0
   #10 [ffffb80edbf37cb8] __purge_vmap_area_lazy at ffffffff9b23a1e0 mm/vmalloc.c:701:0
   #11 [ffffb80edbf37ce0] try_purge_vmap_area_lazy at ffffffff9b23a2cc mm/vmalloc.c:722:0
   #12 [ffffb80edbf37ce0] free_vmap_area_noflush at ffffffff9b23a2cc mm/vmalloc.c:754:0
   #13 [ffffb80edbf37cf8] free_unmap_vmap_area at ffffffff9b23bb3b mm/vmalloc.c:764:0
   #14 [ffffb80edbf37cf8] remove_vm_area at ffffffff9b23bb3b mm/vmalloc.c:1509:0
   #15 [ffffb80edbf37d18] __vunmap at ffffffff9b23bb8a mm/vmalloc.c:1537:0
   #16 [ffffb80edbf37d40] vfree at ffffffff9b23bc85 mm/vmalloc.c:1612:0
   #17 [ffffb80edbf37d58] megasas_free_host_crash_buffer [megaraid_sas] at ffffffffc020b7f2 drivers/scsi/megaraid/megaraid_sas_fusion.c:3932:0
   #18 [ffffb80edbf37d80] fw_crash_state_store [megaraid_sas] at ffffffffc01f804d drivers/scsi/megaraid/megaraid_sas_base.c:3291:0
   #19 [ffffb80edbf37dc0] dev_attr_store at ffffffff9b56dd7b drivers/base/core.c:758:0
   #20 [ffffb80edbf37dd0] sysfs_kf_write at ffffffff9b326acf fs/sysfs/file.c:144:0
   #21 [ffffb80edbf37de0] kernfs_fop_write at ffffffff9b325fd4 fs/kernfs/file.c:316:0
   #22 [ffffb80edbf37e20] __vfs_write at ffffffff9b29418a fs/read_write.c:480:0
   #23 [ffffb80edbf37ea8] vfs_write at ffffffff9b294462 fs/read_write.c:544:0
   #24 [ffffb80edbf37ee8] SYSC_write at ffffffff9b2946ec fs/read_write.c:590:0
   #25 [ffffb80edbf37ee8] SyS_write at ffffffff9b2946ec fs/read_write.c:582:0
   #26 [ffffb80edbf37f30] do_syscall_64 at ffffffff9b003ca9 arch/x86/entry/common.c:298:0
   #27 [ffffb80edbf37f58] entry_SYSCALL_64 at ffffffff9ba001b1 arch/x86/entry/entry_64.S:238:0

  PID: 17355    TASK: ffff95c1090c3d80  CPU: 29  COMMAND: "mrdiagd"
  !# 0 [ffffb80f2d3c7d30] __read_once_size at ffffffff9b0f2ab0 include/linux/compiler.h:185:0
  !# 1 [ffffb80f2d3c7d30] native_queued_spin_lock_slowpath at ffffffff9b0f2ab0 kernel/locking/qspinlock.c:368:0
   # 2 [ffffb80f2d3c7d58] pv_queued_spin_lock_slowpath at ffffffff9b0f244b arch/x86/include/asm/paravirt.h:674:0
   # 3 [ffffb80f2d3c7d58] queued_spin_lock_slowpath at ffffffff9b0f244b arch/x86/include/asm/qspinlock.h:53:0
   # 4 [ffffb80f2d3c7d68] queued_spin_lock at ffffffff9b8961a6 include/asm-generic/qspinlock.h:90:0
   # 5 [ffffb80f2d3c7d68] do_raw_spin_lock_flags at ffffffff9b8961a6 include/linux/spinlock.h:173:0
   # 6 [ffffb80f2d3c7d68] __raw_spin_lock_irqsave at ffffffff9b8961a6 include/linux/spinlock_api_smp.h:122:0
   # 7 [ffffb80f2d3c7d68] _raw_spin_lock_irqsave at ffffffff9b8961a6 kernel/locking/spinlock.c:160:0
   # 8 [ffffb80f2d3c7d88] fw_crash_buffer_store [megaraid_sas] at ffffffffc01f8129 drivers/scsi/megaraid/megaraid_sas_base.c:3205:0
   # 9 [ffffb80f2d3c7dc0] dev_attr_store at ffffffff9b56dd7b drivers/base/core.c:758:0
   #10 [ffffb80f2d3c7dd0] sysfs_kf_write at ffffffff9b326acf fs/sysfs/file.c:144:0
   #11 [ffffb80f2d3c7de0] kernfs_fop_write at ffffffff9b325fd4 fs/kernfs/file.c:316:0
   #12 [ffffb80f2d3c7e20] __vfs_write at ffffffff9b29418a fs/read_write.c:480:0
   #13 [ffffb80f2d3c7ea8] vfs_write at ffffffff9b294462 fs/read_write.c:544:0
   #14 [ffffb80f2d3c7ee8] SYSC_write at ffffffff9b2946ec fs/read_write.c:590:0
   #15 [ffffb80f2d3c7ee8] SyS_write at ffffffff9b2946ec fs/read_write.c:582:0
   #16 [ffffb80f2d3c7f30] do_syscall_64 at ffffffff9b003ca9 arch/x86/entry/common.c:298:0
   #17 [ffffb80f2d3c7f58] entry_SYSCALL_64 at ffffffff9ba001b1 arch/x86/entry/entry_64.S:238:0

The lock is used to synchronize different sysfs operations, it doesn't
protect any resource that will be touched by an interrupt. Consequently
it's not required to disable IRQs. Replace the spinlock with a mutex to fix
the deadlock.

Signed-off-by: Junxiao Bi <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Mike Christie <[email protected]>
Cc: [email protected]
Signed-off-by: Martin K. Petersen <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
nbouchinet-anssi pushed a commit to nbouchinet-anssi/linux-hardened that referenced this pull request Dec 8, 2023
[ Upstream commit a524eab ]

As of commit b92143d ("net: dsa: mv88e6xxx: add infrastructure for
phylink_pcs") probing of a Marvell 88e6350 switch causes a NULL pointer
de-reference like this example:

    ...
    mv88e6085 d0072004.mdio-mii:11: switch 0x3710 detected: Marvell 88E6350, revision 2
    8<--- cut here ---
    Unable to handle kernel NULL pointer dereference at virtual address 00000000 when read
    [00000000] *pgd=00000000
    Internal error: Oops: 5 [anthraxx#1] ARM
    Modules linked in:
    CPU: 0 PID: 8 Comm: kworker/u2:0 Not tainted 6.7.0-rc2-dirty anthraxx#26
    Hardware name: Marvell Armada 370/XP (Device Tree)
    Workqueue: events_unbound deferred_probe_work_func
    PC is at mv88e6xxx_port_setup+0x1c/0x44
    LR is at dsa_port_devlink_setup+0x74/0x154
    pc : [<c057ea24>]    lr : [<c0819598>]    psr: a0000013
    sp : c184fce0  ip : c542b8f4  fp : 00000000
    r10: 00000001  r9 : c542a540  r8 : c542bc00
    r7 : c542b838  r6 : c5244580  r5 : 00000005  r4 : c5244580
    r3 : 00000000  r2 : c542b840  r1 : 00000005  r0 : c1a02040
    ...

The Marvell 6350 switch has no SERDES interface and so has no
corresponding pcs_ops defined for it. But during probing a call is made
to mv88e6xxx_port_setup() which unconditionally expects pcs_ops to exist -
though the presence of the pcs_ops->pcs_init function is optional.

Modify code to check for pcs_ops first, before checking for and calling
pcs_ops->pcs_init. Modify checking and use of pcs_ops->pcs_teardown
which may potentially suffer the same problem.

Fixes: b92143d ("net: dsa: mv88e6xxx: add infrastructure for phylink_pcs")
Signed-off-by: Greg Ungerer <[email protected]>
Reviewed-by: Andrew Lunn <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
anthraxx pushed a commit that referenced this pull request Feb 13, 2024
commit 56925f3 upstream.

With previous patch, one of subtests in test_btf_id becomes
flaky and may fail. The following is a failing example:

  Error: #26 btf
  Error: #26/174 btf/BTF ID
    Error: #26/174 btf/BTF ID
    btf_raw_create:PASS:check 0 nsec
    btf_raw_create:PASS:check 0 nsec
    test_btf_id:PASS:check 0 nsec
    ...
    test_btf_id:PASS:check 0 nsec
    test_btf_id:FAIL:check BTF lingersdo_test_get_info:FAIL:check failed: -1

The test tries to prove a btf_id not available after the map is closed.
But btf_id is freed only after workqueue and a rcu grace period, compared
to previous case just after a rcu grade period.
Depending on system workload, workqueue could take quite some time
to execute function bpf_map_free_deferred() which may cause the test failure.
Instead of adding arbitrary delays, let us remove the logic to
check btf_id availability after map is closed.

Signed-off-by: Yonghong Song <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
Signed-off-by: Samasth Norway Ananda <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
anthraxx pushed a commit that referenced this pull request Feb 13, 2024
commit 56925f3 upstream.

With previous patch, one of subtests in test_btf_id becomes
flaky and may fail. The following is a failing example:

  Error: #26 btf
  Error: #26/174 btf/BTF ID
    Error: #26/174 btf/BTF ID
    btf_raw_create:PASS:check 0 nsec
    btf_raw_create:PASS:check 0 nsec
    test_btf_id:PASS:check 0 nsec
    ...
    test_btf_id:PASS:check 0 nsec
    test_btf_id:FAIL:check BTF lingersdo_test_get_info:FAIL:check failed: -1

The test tries to prove a btf_id not available after the map is closed.
But btf_id is freed only after workqueue and a rcu grace period, compared
to previous case just after a rcu grade period.
Depending on system workload, workqueue could take quite some time
to execute function bpf_map_free_deferred() which may cause the test failure.
Instead of adding arbitrary delays, let us remove the logic to
check btf_id availability after map is closed.

Signed-off-by: Yonghong Song <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
Signed-off-by: Samasth Norway Ananda <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
anthraxx pushed a commit that referenced this pull request Nov 25, 2024
Syzkaller reported this warning:
 ------------[ cut here ]------------
 WARNING: CPU: 0 PID: 16 at net/ipv4/af_inet.c:156 inet_sock_destruct+0x1c5/0x1e0
 Modules linked in:
 CPU: 0 UID: 0 PID: 16 Comm: ksoftirqd/0 Not tainted 6.12.0-rc5 #26
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
 RIP: 0010:inet_sock_destruct+0x1c5/0x1e0
 Code: 24 12 4c 89 e2 5b 48 c7 c7 98 ec bb 82 41 5c e9 d1 18 17 ff 4c 89 e6 5b 48 c7 c7 d0 ec bb 82 41 5c e9 bf 18 17 ff 0f 0b eb 83 <0f> 0b eb 97 0f 0b eb 87 0f 0b e9 68 ff ff ff 66 66 2e 0f 1f 84 00
 RSP: 0018:ffffc9000008bd90 EFLAGS: 00010206
 RAX: 0000000000000300 RBX: ffff88810b172a90 RCX: 0000000000000007
 RDX: 0000000000000002 RSI: 0000000000000300 RDI: ffff88810b172a00
 RBP: ffff88810b172a00 R08: ffff888104273c00 R09: 0000000000100007
 R10: 0000000000020000 R11: 0000000000000006 R12: ffff88810b172a00
 R13: 0000000000000004 R14: 0000000000000000 R15: ffff888237c31f78
 FS:  0000000000000000(0000) GS:ffff888237c00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00007ffc63fecac8 CR3: 000000000342e000 CR4: 00000000000006f0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 Call Trace:
  <TASK>
  ? __warn+0x88/0x130
  ? inet_sock_destruct+0x1c5/0x1e0
  ? report_bug+0x18e/0x1a0
  ? handle_bug+0x53/0x90
  ? exc_invalid_op+0x18/0x70
  ? asm_exc_invalid_op+0x1a/0x20
  ? inet_sock_destruct+0x1c5/0x1e0
  __sk_destruct+0x2a/0x200
  rcu_do_batch+0x1aa/0x530
  ? rcu_do_batch+0x13b/0x530
  rcu_core+0x159/0x2f0
  handle_softirqs+0xd3/0x2b0
  ? __pfx_smpboot_thread_fn+0x10/0x10
  run_ksoftirqd+0x25/0x30
  smpboot_thread_fn+0xdd/0x1d0
  kthread+0xd3/0x100
  ? __pfx_kthread+0x10/0x10
  ret_from_fork+0x34/0x50
  ? __pfx_kthread+0x10/0x10
  ret_from_fork_asm+0x1a/0x30
  </TASK>
 ---[ end trace 0000000000000000 ]---

Its possible that two threads call tcp_v6_do_rcv()/sk_forward_alloc_add()
concurrently when sk->sk_state == TCP_LISTEN with sk->sk_lock unlocked,
which triggers a data-race around sk->sk_forward_alloc:
tcp_v6_rcv
    tcp_v6_do_rcv
        skb_clone_and_charge_r
            sk_rmem_schedule
                __sk_mem_schedule
                    sk_forward_alloc_add()
            skb_set_owner_r
                sk_mem_charge
                    sk_forward_alloc_add()
        __kfree_skb
            skb_release_all
                skb_release_head_state
                    sock_rfree
                        sk_mem_uncharge
                            sk_forward_alloc_add()
                            sk_mem_reclaim
                                // set local var reclaimable
                                __sk_mem_reclaim
                                    sk_forward_alloc_add()

In this syzkaller testcase, two threads call
tcp_v6_do_rcv() with skb->truesize=768, the sk_forward_alloc changes like
this:
 (cpu 1)             | (cpu 2)             | sk_forward_alloc
 ...                 | ...                 | 0
 __sk_mem_schedule() |                     | +4096 = 4096
                     | __sk_mem_schedule() | +4096 = 8192
 sk_mem_charge()     |                     | -768  = 7424
                     | sk_mem_charge()     | -768  = 6656
 ...                 |    ...              |
 sk_mem_uncharge()   |                     | +768  = 7424
 reclaimable=7424    |                     |
                     | sk_mem_uncharge()   | +768  = 8192
                     | reclaimable=8192    |
 __sk_mem_reclaim()  |                     | -4096 = 4096
                     | __sk_mem_reclaim()  | -8192 = -4096 != 0

The skb_clone_and_charge_r() should not be called in tcp_v6_do_rcv() when
sk->sk_state is TCP_LISTEN, it happens later in tcp_v6_syn_recv_sock().
Fix the same issue in dccp_v6_do_rcv().

Suggested-by: Eric Dumazet <[email protected]>
Reviewed-by: Eric Dumazet <[email protected]>
Fixes: e994b2f ("tcp: do not lock listener to process SYN packets")
Signed-off-by: Wang Liang <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
anthraxx pushed a commit that referenced this pull request Nov 25, 2024
[ Upstream commit 073d898 ]

Syzkaller reported this warning:
 ------------[ cut here ]------------
 WARNING: CPU: 0 PID: 16 at net/ipv4/af_inet.c:156 inet_sock_destruct+0x1c5/0x1e0
 Modules linked in:
 CPU: 0 UID: 0 PID: 16 Comm: ksoftirqd/0 Not tainted 6.12.0-rc5 #26
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
 RIP: 0010:inet_sock_destruct+0x1c5/0x1e0
 Code: 24 12 4c 89 e2 5b 48 c7 c7 98 ec bb 82 41 5c e9 d1 18 17 ff 4c 89 e6 5b 48 c7 c7 d0 ec bb 82 41 5c e9 bf 18 17 ff 0f 0b eb 83 <0f> 0b eb 97 0f 0b eb 87 0f 0b e9 68 ff ff ff 66 66 2e 0f 1f 84 00
 RSP: 0018:ffffc9000008bd90 EFLAGS: 00010206
 RAX: 0000000000000300 RBX: ffff88810b172a90 RCX: 0000000000000007
 RDX: 0000000000000002 RSI: 0000000000000300 RDI: ffff88810b172a00
 RBP: ffff88810b172a00 R08: ffff888104273c00 R09: 0000000000100007
 R10: 0000000000020000 R11: 0000000000000006 R12: ffff88810b172a00
 R13: 0000000000000004 R14: 0000000000000000 R15: ffff888237c31f78
 FS:  0000000000000000(0000) GS:ffff888237c00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00007ffc63fecac8 CR3: 000000000342e000 CR4: 00000000000006f0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 Call Trace:
  <TASK>
  ? __warn+0x88/0x130
  ? inet_sock_destruct+0x1c5/0x1e0
  ? report_bug+0x18e/0x1a0
  ? handle_bug+0x53/0x90
  ? exc_invalid_op+0x18/0x70
  ? asm_exc_invalid_op+0x1a/0x20
  ? inet_sock_destruct+0x1c5/0x1e0
  __sk_destruct+0x2a/0x200
  rcu_do_batch+0x1aa/0x530
  ? rcu_do_batch+0x13b/0x530
  rcu_core+0x159/0x2f0
  handle_softirqs+0xd3/0x2b0
  ? __pfx_smpboot_thread_fn+0x10/0x10
  run_ksoftirqd+0x25/0x30
  smpboot_thread_fn+0xdd/0x1d0
  kthread+0xd3/0x100
  ? __pfx_kthread+0x10/0x10
  ret_from_fork+0x34/0x50
  ? __pfx_kthread+0x10/0x10
  ret_from_fork_asm+0x1a/0x30
  </TASK>
 ---[ end trace 0000000000000000 ]---

Its possible that two threads call tcp_v6_do_rcv()/sk_forward_alloc_add()
concurrently when sk->sk_state == TCP_LISTEN with sk->sk_lock unlocked,
which triggers a data-race around sk->sk_forward_alloc:
tcp_v6_rcv
    tcp_v6_do_rcv
        skb_clone_and_charge_r
            sk_rmem_schedule
                __sk_mem_schedule
                    sk_forward_alloc_add()
            skb_set_owner_r
                sk_mem_charge
                    sk_forward_alloc_add()
        __kfree_skb
            skb_release_all
                skb_release_head_state
                    sock_rfree
                        sk_mem_uncharge
                            sk_forward_alloc_add()
                            sk_mem_reclaim
                                // set local var reclaimable
                                __sk_mem_reclaim
                                    sk_forward_alloc_add()

In this syzkaller testcase, two threads call
tcp_v6_do_rcv() with skb->truesize=768, the sk_forward_alloc changes like
this:
 (cpu 1)             | (cpu 2)             | sk_forward_alloc
 ...                 | ...                 | 0
 __sk_mem_schedule() |                     | +4096 = 4096
                     | __sk_mem_schedule() | +4096 = 8192
 sk_mem_charge()     |                     | -768  = 7424
                     | sk_mem_charge()     | -768  = 6656
 ...                 |    ...              |
 sk_mem_uncharge()   |                     | +768  = 7424
 reclaimable=7424    |                     |
                     | sk_mem_uncharge()   | +768  = 8192
                     | reclaimable=8192    |
 __sk_mem_reclaim()  |                     | -4096 = 4096
                     | __sk_mem_reclaim()  | -8192 = -4096 != 0

The skb_clone_and_charge_r() should not be called in tcp_v6_do_rcv() when
sk->sk_state is TCP_LISTEN, it happens later in tcp_v6_syn_recv_sock().
Fix the same issue in dccp_v6_do_rcv().

Suggested-by: Eric Dumazet <[email protected]>
Reviewed-by: Eric Dumazet <[email protected]>
Fixes: e994b2f ("tcp: do not lock listener to process SYN packets")
Signed-off-by: Wang Liang <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
anthraxx pushed a commit that referenced this pull request Dec 19, 2024
[ Upstream commit 7a17308c17880d259105f6e591eb1bc77b9612f0 ]

This fixes the circular locking dependency warning below, by reworking
iso_sock_recvmsg, to ensure that the socket lock is always released
before calling a function that locks hdev.

[  561.670344] ======================================================
[  561.670346] WARNING: possible circular locking dependency detected
[  561.670349] 6.12.0-rc6+ #26 Not tainted
[  561.670351] ------------------------------------------------------
[  561.670353] iso-tester/3289 is trying to acquire lock:
[  561.670355] ffff88811f600078 (&hdev->lock){+.+.}-{3:3},
               at: iso_conn_big_sync+0x73/0x260 [bluetooth]
[  561.670405]
               but task is already holding lock:
[  561.670407] ffff88815af58258 (sk_lock-AF_BLUETOOTH){+.+.}-{0:0},
               at: iso_sock_recvmsg+0xbf/0x500 [bluetooth]
[  561.670450]
               which lock already depends on the new lock.

[  561.670452]
               the existing dependency chain (in reverse order) is:
[  561.670453]
               -> #2 (sk_lock-AF_BLUETOOTH){+.+.}-{0:0}:
[  561.670458]        lock_acquire+0x7c/0xc0
[  561.670463]        lock_sock_nested+0x3b/0xf0
[  561.670467]        bt_accept_dequeue+0x1a5/0x4d0 [bluetooth]
[  561.670510]        iso_sock_accept+0x271/0x830 [bluetooth]
[  561.670547]        do_accept+0x3dd/0x610
[  561.670550]        __sys_accept4+0xd8/0x170
[  561.670553]        __x64_sys_accept+0x74/0xc0
[  561.670556]        x64_sys_call+0x17d6/0x25f0
[  561.670559]        do_syscall_64+0x87/0x150
[  561.670563]        entry_SYSCALL_64_after_hwframe+0x76/0x7e
[  561.670567]
               -> #1 (sk_lock-AF_BLUETOOTH-BTPROTO_ISO){+.+.}-{0:0}:
[  561.670571]        lock_acquire+0x7c/0xc0
[  561.670574]        lock_sock_nested+0x3b/0xf0
[  561.670577]        iso_sock_listen+0x2de/0xf30 [bluetooth]
[  561.670617]        __sys_listen_socket+0xef/0x130
[  561.670620]        __x64_sys_listen+0xe1/0x190
[  561.670623]        x64_sys_call+0x2517/0x25f0
[  561.670626]        do_syscall_64+0x87/0x150
[  561.670629]        entry_SYSCALL_64_after_hwframe+0x76/0x7e
[  561.670632]
               -> #0 (&hdev->lock){+.+.}-{3:3}:
[  561.670636]        __lock_acquire+0x32ad/0x6ab0
[  561.670639]        lock_acquire.part.0+0x118/0x360
[  561.670642]        lock_acquire+0x7c/0xc0
[  561.670644]        __mutex_lock+0x18d/0x12f0
[  561.670647]        mutex_lock_nested+0x1b/0x30
[  561.670651]        iso_conn_big_sync+0x73/0x260 [bluetooth]
[  561.670687]        iso_sock_recvmsg+0x3e9/0x500 [bluetooth]
[  561.670722]        sock_recvmsg+0x1d5/0x240
[  561.670725]        sock_read_iter+0x27d/0x470
[  561.670727]        vfs_read+0x9a0/0xd30
[  561.670731]        ksys_read+0x1a8/0x250
[  561.670733]        __x64_sys_read+0x72/0xc0
[  561.670736]        x64_sys_call+0x1b12/0x25f0
[  561.670738]        do_syscall_64+0x87/0x150
[  561.670741]        entry_SYSCALL_64_after_hwframe+0x76/0x7e
[  561.670744]
               other info that might help us debug this:

[  561.670745] Chain exists of:
&hdev->lock --> sk_lock-AF_BLUETOOTH-BTPROTO_ISO --> sk_lock-AF_BLUETOOTH

[  561.670751]  Possible unsafe locking scenario:

[  561.670753]        CPU0                    CPU1
[  561.670754]        ----                    ----
[  561.670756]   lock(sk_lock-AF_BLUETOOTH);
[  561.670758]                                lock(sk_lock
                                              AF_BLUETOOTH-BTPROTO_ISO);
[  561.670761]                                lock(sk_lock-AF_BLUETOOTH);
[  561.670764]   lock(&hdev->lock);
[  561.670767]
                *** DEADLOCK ***

Fixes: 07a9342b94a9 ("Bluetooth: ISO: Send BIG Create Sync via hci_sync")
Signed-off-by: Iulia Tanasescu <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
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