mm, treewide: rename kzfree() to kfree_sensitive()

As said by Linus: A symmetric naming is only helpful if it implies symmetries in use. Otherwise it's actively misleading. In "kzalloc()", the z is meaningful and an important part of what the caller wants. In "kzfree()", the z is actively detrimental, because maybe in the future we really _might_ want to use that "memfill(0xdeadbeef)" or something. The "zero" part of the interface isn't even _relevant_. The main reason that kzfree() exists is to clear sensitive information that should not be leaked to other future users of the same memory objects. Rename kzfree() to kfree_sensitive() to follow the example of the recently added kvfree_sensitive() and make the intention of the API more explicit. In addition, memzero_explicit() is used to clear the memory to make sure that it won't get optimized away by the compiler. The renaming is done by using the command sequence: git grep -w --name-only kzfree |\ xargs sed -i 's/kzfree/kfree_sensitive/' followed by some editing of the kfree_sensitive() kerneldoc and adding a kzfree backward compatibility macro in slab.h. [[email protected]: fs/crypto/inline_crypt.c needs linux/slab.h] [[email protected]: fix fs/crypto/inline_crypt.c some more] Suggested-by: Joe Perches <[email protected]> Signed-off-by: Waiman Long <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Acked-by: David Howells <[email protected]> Acked-by: Michal Hocko <[email protected]> Acked-by: Johannes Weiner <[email protected]> Cc: Jarkko Sakkinen <[email protected]> Cc: James Morris <[email protected]> Cc: "Serge E. Hallyn" <[email protected]> Cc: Joe Perches <[email protected]> Cc: Matthew Wilcox <[email protected]> Cc: David Rientjes <[email protected]> Cc: Dan Carpenter <[email protected]> Cc: "Jason A . Donenfeld" <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Linus Torvalds <[email protected]>
pav511 · Aug 7, 2020 · 453431a · 453431a
1 parent 57c720d
commit 453431a
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Showing 114 changed files with 323 additions and 320 deletions.
diff --git a/arch/s390/crypto/prng.c b/arch/s390/crypto/prng.c
@@ -249,7 +249,7 @@ static void prng_tdes_deinstantiate(void)
 {
 	pr_debug("The prng module stopped "
 		 "after running in triple DES mode\n");
-	kzfree(prng_data);
+	kfree_sensitive(prng_data);
 }
 
 
@@ -442,7 +442,7 @@ static int __init prng_sha512_instantiate(void)
 static void prng_sha512_deinstantiate(void)
 {
 	pr_debug("The prng module stopped after running in SHA-512 mode\n");
-	kzfree(prng_data);
+	kfree_sensitive(prng_data);
 }
 
 

diff --git a/arch/x86/power/hibernate.c b/arch/x86/power/hibernate.c
@@ -98,7 +98,7 @@ static int get_e820_md5(struct e820_table *table, void *buf)
 	if (crypto_shash_digest(desc, (u8 *)table, size, buf))
 		ret = -EINVAL;
 
-	kzfree(desc);
+	kfree_sensitive(desc);
 
 free_tfm:
 	crypto_free_shash(tfm);

diff --git a/crypto/adiantum.c b/crypto/adiantum.c
@@ -177,7 +177,7 @@ static int adiantum_setkey(struct crypto_skcipher *tfm, const u8 *key,
 	keyp += NHPOLY1305_KEY_SIZE;
 	WARN_ON(keyp != &data->derived_keys[ARRAY_SIZE(data->derived_keys)]);
 out:
-	kzfree(data);
+	kfree_sensitive(data);
 	return err;
 }
 

diff --git a/crypto/ahash.c b/crypto/ahash.c
@@ -183,7 +183,7 @@ static int ahash_setkey_unaligned(struct crypto_ahash *tfm, const u8 *key,
 	alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
 	memcpy(alignbuffer, key, keylen);
 	ret = tfm->setkey(tfm, alignbuffer, keylen);
-	kzfree(buffer);
+	kfree_sensitive(buffer);
 	return ret;
 }
 
@@ -302,7 +302,7 @@ static void ahash_restore_req(struct ahash_request *req, int err)
 	req->priv = NULL;
 
 	/* Free the req->priv.priv from the ADJUSTED request. */
-	kzfree(priv);
+	kfree_sensitive(priv);
 }
 
 static void ahash_notify_einprogress(struct ahash_request *req)

diff --git a/crypto/api.c b/crypto/api.c
@@ -571,7 +571,7 @@ void crypto_destroy_tfm(void *mem, struct crypto_tfm *tfm)
 		alg->cra_exit(tfm);
 	crypto_exit_ops(tfm);
 	crypto_mod_put(alg);
-	kzfree(mem);
+	kfree_sensitive(mem);
 }
 EXPORT_SYMBOL_GPL(crypto_destroy_tfm);
 

diff --git a/crypto/asymmetric_keys/verify_pefile.c b/crypto/asymmetric_keys/verify_pefile.c
@@ -376,7 +376,7 @@ static int pefile_digest_pe(const void *pebuf, unsigned int pelen,
 	}
 
 error:
-	kzfree(desc);
+	kfree_sensitive(desc);
 error_no_desc:
 	crypto_free_shash(tfm);
 	kleave(" = %d", ret);
@@ -447,6 +447,6 @@ int verify_pefile_signature(const void *pebuf, unsigned pelen,
 	ret = pefile_digest_pe(pebuf, pelen, &ctx);
 
 error:
-	kzfree(ctx.digest);
+	kfree_sensitive(ctx.digest);
 	return ret;
 }
diff --git a/crypto/deflate.c b/crypto/deflate.c
@@ -163,7 +163,7 @@ static void __deflate_exit(void *ctx)
 static void deflate_free_ctx(struct crypto_scomp *tfm, void *ctx)
 {
 	__deflate_exit(ctx);
-	kzfree(ctx);
+	kfree_sensitive(ctx);
 }
 
 static void deflate_exit(struct crypto_tfm *tfm)

diff --git a/crypto/drbg.c b/crypto/drbg.c
@@ -1218,19 +1218,19 @@ static inline void drbg_dealloc_state(struct drbg_state *drbg)
 {
 	if (!drbg)
 		return;
-	kzfree(drbg->Vbuf);
+	kfree_sensitive(drbg->Vbuf);
 	drbg->Vbuf = NULL;
 	drbg->V = NULL;
-	kzfree(drbg->Cbuf);
+	kfree_sensitive(drbg->Cbuf);
 	drbg->Cbuf = NULL;
 	drbg->C = NULL;
-	kzfree(drbg->scratchpadbuf);
+	kfree_sensitive(drbg->scratchpadbuf);
 	drbg->scratchpadbuf = NULL;
 	drbg->reseed_ctr = 0;
 	drbg->d_ops = NULL;
 	drbg->core = NULL;
 	if (IS_ENABLED(CONFIG_CRYPTO_FIPS)) {
-		kzfree(drbg->prev);
+		kfree_sensitive(drbg->prev);
 		drbg->prev = NULL;
 		drbg->fips_primed = false;
 	}
@@ -1701,7 +1701,7 @@ static int drbg_fini_hash_kernel(struct drbg_state *drbg)
 	struct sdesc *sdesc = (struct sdesc *)drbg->priv_data;
 	if (sdesc) {
 		crypto_free_shash(sdesc->shash.tfm);
-		kzfree(sdesc);
+		kfree_sensitive(sdesc);
 	}
 	drbg->priv_data = NULL;
 	return 0;

diff --git a/crypto/ecc.c b/crypto/ecc.c
@@ -67,7 +67,7 @@ static u64 *ecc_alloc_digits_space(unsigned int ndigits)
 
 static void ecc_free_digits_space(u64 *space)
 {
-	kzfree(space);
+	kfree_sensitive(space);
 }
 
 static struct ecc_point *ecc_alloc_point(unsigned int ndigits)
@@ -101,9 +101,9 @@ static void ecc_free_point(struct ecc_point *p)
 	if (!p)
 		return;
 
-	kzfree(p->x);
-	kzfree(p->y);
-	kzfree(p);
+	kfree_sensitive(p->x);
+	kfree_sensitive(p->y);
+	kfree_sensitive(p);
 }
 
 static void vli_clear(u64 *vli, unsigned int ndigits)

diff --git a/crypto/ecdh.c b/crypto/ecdh.c
@@ -124,7 +124,7 @@ static int ecdh_compute_value(struct kpp_request *req)
 
 	/* fall through */
 free_all:
-	kzfree(shared_secret);
+	kfree_sensitive(shared_secret);
 free_pubkey:
 	kfree(public_key);
 	return ret;

diff --git a/crypto/gcm.c b/crypto/gcm.c
@@ -139,7 +139,7 @@ static int crypto_gcm_setkey(struct crypto_aead *aead, const u8 *key,
 			       CRYPTO_TFM_REQ_MASK);
 	err = crypto_ahash_setkey(ghash, (u8 *)&data->hash, sizeof(be128));
 out:
-	kzfree(data);
+	kfree_sensitive(data);
 	return err;
 }
 

diff --git a/crypto/gf128mul.c b/crypto/gf128mul.c
@@ -304,8 +304,8 @@ void gf128mul_free_64k(struct gf128mul_64k *t)
 	int i;
 
 	for (i = 0; i < 16; i++)
-		kzfree(t->t[i]);
-	kzfree(t);
+		kfree_sensitive(t->t[i]);
+	kfree_sensitive(t);
 }
 EXPORT_SYMBOL(gf128mul_free_64k);
 

diff --git a/crypto/jitterentropy-kcapi.c b/crypto/jitterentropy-kcapi.c
@@ -57,7 +57,7 @@ void *jent_zalloc(unsigned int len)
 
 void jent_zfree(void *ptr)
 {
-	kzfree(ptr);
+	kfree_sensitive(ptr);
 }
 
 int jent_fips_enabled(void)

diff --git a/crypto/rng.c b/crypto/rng.c
@@ -53,7 +53,7 @@ int crypto_rng_reset(struct crypto_rng *tfm, const u8 *seed, unsigned int slen)
 	err = crypto_rng_alg(tfm)->seed(tfm, seed, slen);
 	crypto_stats_rng_seed(alg, err);
 out:
-	kzfree(buf);
+	kfree_sensitive(buf);
 	return err;
 }
 EXPORT_SYMBOL_GPL(crypto_rng_reset);

diff --git a/crypto/rsa-pkcs1pad.c b/crypto/rsa-pkcs1pad.c
@@ -199,7 +199,7 @@ static int pkcs1pad_encrypt_sign_complete(struct akcipher_request *req, int err)
 	sg_copy_from_buffer(req->dst,
 			    sg_nents_for_len(req->dst, ctx->key_size),
 			    out_buf, ctx->key_size);
-	kzfree(out_buf);
+	kfree_sensitive(out_buf);
 
 out:
 	req->dst_len = ctx->key_size;
@@ -322,7 +322,7 @@ static int pkcs1pad_decrypt_complete(struct akcipher_request *req, int err)
 				out_buf + pos, req->dst_len);
 
 done:
-	kzfree(req_ctx->out_buf);
+	kfree_sensitive(req_ctx->out_buf);
 
 	return err;
 }
@@ -500,7 +500,7 @@ static int pkcs1pad_verify_complete(struct akcipher_request *req, int err)
 		   req->dst_len) != 0)
 		err = -EKEYREJECTED;
 done:
-	kzfree(req_ctx->out_buf);
+	kfree_sensitive(req_ctx->out_buf);
 
 	return err;
 }

diff --git a/crypto/seqiv.c b/crypto/seqiv.c
@@ -33,7 +33,7 @@ static void seqiv_aead_encrypt_complete2(struct aead_request *req, int err)
 	memcpy(req->iv, subreq->iv, crypto_aead_ivsize(geniv));
 
 out:
-	kzfree(subreq->iv);
+	kfree_sensitive(subreq->iv);
 }
 
 static void seqiv_aead_encrypt_complete(struct crypto_async_request *base,

diff --git a/crypto/shash.c b/crypto/shash.c
@@ -44,7 +44,7 @@ static int shash_setkey_unaligned(struct crypto_shash *tfm, const u8 *key,
 	alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
 	memcpy(alignbuffer, key, keylen);
 	err = shash->setkey(tfm, alignbuffer, keylen);
-	kzfree(buffer);
+	kfree_sensitive(buffer);
 	return err;
 }
 

diff --git a/crypto/skcipher.c b/crypto/skcipher.c
@@ -592,7 +592,7 @@ static int skcipher_setkey_unaligned(struct crypto_skcipher *tfm,
 	alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
 	memcpy(alignbuffer, key, keylen);
 	ret = cipher->setkey(tfm, alignbuffer, keylen);
-	kzfree(buffer);
+	kfree_sensitive(buffer);
 	return ret;
 }
 

diff --git a/crypto/testmgr.c b/crypto/testmgr.c
@@ -1744,7 +1744,7 @@ static int test_hash_vs_generic_impl(const char *driver,
 	kfree(vec.plaintext);
 	kfree(vec.digest);
 	crypto_free_shash(generic_tfm);
-	kzfree(generic_desc);
+	kfree_sensitive(generic_desc);
 	return err;
 }
 #else /* !CONFIG_CRYPTO_MANAGER_EXTRA_TESTS */
@@ -3665,7 +3665,7 @@ static int drbg_cavs_test(const struct drbg_testvec *test, int pr,
 	if (IS_ERR(drng)) {
 		printk(KERN_ERR "alg: drbg: could not allocate DRNG handle for "
 		       "%s\n", driver);
-		kzfree(buf);
+		kfree_sensitive(buf);
 		return -ENOMEM;
 	}
 
@@ -3712,7 +3712,7 @@ static int drbg_cavs_test(const struct drbg_testvec *test, int pr,
 
 outbuf:
 	crypto_free_rng(drng);
-	kzfree(buf);
+	kfree_sensitive(buf);
 	return ret;
 }
 

diff --git a/crypto/zstd.c b/crypto/zstd.c
@@ -137,7 +137,7 @@ static void __zstd_exit(void *ctx)
 static void zstd_free_ctx(struct crypto_scomp *tfm, void *ctx)
 {
 	__zstd_exit(ctx);
-	kzfree(ctx);
+	kfree_sensitive(ctx);
 }
 
 static void zstd_exit(struct crypto_tfm *tfm)

diff --git a/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-cipher.c b/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-cipher.c
@@ -254,7 +254,7 @@ static int sun8i_ce_cipher(struct skcipher_request *areq)
 		offset = areq->cryptlen - ivsize;
 		if (rctx->op_dir & CE_DECRYPTION) {
 			memcpy(areq->iv, backup_iv, ivsize);
-			kzfree(backup_iv);
+			kfree_sensitive(backup_iv);
 		} else {
 			scatterwalk_map_and_copy(areq->iv, areq->dst, offset,
 						 ivsize, 0);

diff --git a/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-cipher.c b/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-cipher.c
@@ -249,7 +249,7 @@ static int sun8i_ss_cipher(struct skcipher_request *areq)
 			if (rctx->op_dir & SS_DECRYPTION) {
 				memcpy(areq->iv, backup_iv, ivsize);
 				memzero_explicit(backup_iv, ivsize);
-				kzfree(backup_iv);
+				kfree_sensitive(backup_iv);
 			} else {
 				scatterwalk_map_and_copy(areq->iv, areq->dst, offset,
 							 ivsize, 0);

diff --git a/drivers/crypto/amlogic/amlogic-gxl-cipher.c b/drivers/crypto/amlogic/amlogic-gxl-cipher.c
@@ -252,8 +252,8 @@ static int meson_cipher(struct skcipher_request *areq)
 		}
 	}
 theend:
-	kzfree(bkeyiv);
-	kzfree(backup_iv);
+	kfree_sensitive(bkeyiv);
+	kfree_sensitive(backup_iv);
 
 	return err;
 }

diff --git a/drivers/crypto/atmel-ecc.c b/drivers/crypto/atmel-ecc.c
@@ -69,7 +69,7 @@ static void atmel_ecdh_done(struct atmel_i2c_work_data *work_data, void *areq,
 
 	/* fall through */
 free_work_data:
-	kzfree(work_data);
+	kfree_sensitive(work_data);
 	kpp_request_complete(req, status);
 }
 

diff --git a/drivers/crypto/caam/caampkc.c b/drivers/crypto/caam/caampkc.c
@@ -854,14 +854,14 @@ static int caam_rsa_dec(struct akcipher_request *req)
 
 static void caam_rsa_free_key(struct caam_rsa_key *key)
 {
-	kzfree(key->d);
-	kzfree(key->p);
-	kzfree(key->q);
-	kzfree(key->dp);
-	kzfree(key->dq);
-	kzfree(key->qinv);
-	kzfree(key->tmp1);
-	kzfree(key->tmp2);
+	kfree_sensitive(key->d);
+	kfree_sensitive(key->p);
+	kfree_sensitive(key->q);
+	kfree_sensitive(key->dp);
+	kfree_sensitive(key->dq);
+	kfree_sensitive(key->qinv);
+	kfree_sensitive(key->tmp1);
+	kfree_sensitive(key->tmp2);
 	kfree(key->e);
 	kfree(key->n);
 	memset(key, 0, sizeof(*key));
@@ -1018,17 +1018,17 @@ static void caam_rsa_set_priv_key_form(struct caam_rsa_ctx *ctx,
 	return;
 
 free_dq:
-	kzfree(rsa_key->dq);
+	kfree_sensitive(rsa_key->dq);
 free_dp:
-	kzfree(rsa_key->dp);
+	kfree_sensitive(rsa_key->dp);
 free_tmp2:
-	kzfree(rsa_key->tmp2);
+	kfree_sensitive(rsa_key->tmp2);
 free_tmp1:
-	kzfree(rsa_key->tmp1);
+	kfree_sensitive(rsa_key->tmp1);
 free_q:
-	kzfree(rsa_key->q);
+	kfree_sensitive(rsa_key->q);
 free_p:
-	kzfree(rsa_key->p);
+	kfree_sensitive(rsa_key->p);
 }
 
 static int caam_rsa_set_priv_key(struct crypto_akcipher *tfm, const void *key,

diff --git a/drivers/crypto/cavium/cpt/cptvf_main.c b/drivers/crypto/cavium/cpt/cptvf_main.c
@@ -74,7 +74,7 @@ static void cleanup_worker_threads(struct cpt_vf *cptvf)
 	for (i = 0; i < cptvf->nr_queues; i++)
 		tasklet_kill(&cwqe_info->vq_wqe[i].twork);
 
-	kzfree(cwqe_info);
+	kfree_sensitive(cwqe_info);
 	cptvf->wqe_info = NULL;
 }
 
@@ -88,7 +88,7 @@ static void free_pending_queues(struct pending_qinfo *pqinfo)
 			continue;
 
 		/* free single queue */
-		kzfree((queue->head));
+		kfree_sensitive((queue->head));
 
 		queue->front = 0;
 		queue->rear = 0;
@@ -189,7 +189,7 @@ static void free_command_queues(struct cpt_vf *cptvf,
 			chunk->head = NULL;
 			chunk->dma_addr = 0;
 			hlist_del(&chunk->nextchunk);
-			kzfree(chunk);
+			kfree_sensitive(chunk);
 		}
 
 		queue->nchunks = 0;