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authorEric Biggers <ebiggers@google.com>2019-01-04 05:16:13 +0100
committerHerbert Xu <herbert@gondor.apana.org.au>2019-01-11 07:16:57 +0100
commit251b7aea34ba3c4d4fdfa9447695642eb8b8b098 (patch)
tree4e2b2ce50c7f79ac784abfc4332f2301d51cf4e9 /crypto/pcbc.c
parentcrypto: ofb - fix handling partial blocks and make thread-safe (diff)
downloadlinux-251b7aea34ba3c4d4fdfa9447695642eb8b8b098.tar.xz
linux-251b7aea34ba3c4d4fdfa9447695642eb8b8b098.zip
crypto: pcbc - remove bogus memcpy()s with src == dest
The memcpy()s in the PCBC implementation use walk->iv as both the source and destination, which has undefined behavior. These memcpy()'s are actually unneeded, because walk->iv is already used to hold the previous plaintext block XOR'd with the previous ciphertext block. Thus, walk->iv is already updated to its final value. So remove the broken and unnecessary memcpy()s. Fixes: 91652be5d1b9 ("[CRYPTO] pcbc: Add Propagated CBC template") Cc: <stable@vger.kernel.org> # v2.6.21+ Cc: David Howells <dhowells@redhat.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'crypto/pcbc.c')
-rw-r--r--crypto/pcbc.c14
1 files changed, 4 insertions, 10 deletions
diff --git a/crypto/pcbc.c b/crypto/pcbc.c
index 8aa10144407c..1b182dfedc94 100644
--- a/crypto/pcbc.c
+++ b/crypto/pcbc.c
@@ -51,7 +51,7 @@ static int crypto_pcbc_encrypt_segment(struct skcipher_request *req,
unsigned int nbytes = walk->nbytes;
u8 *src = walk->src.virt.addr;
u8 *dst = walk->dst.virt.addr;
- u8 *iv = walk->iv;
+ u8 * const iv = walk->iv;
do {
crypto_xor(iv, src, bsize);
@@ -72,7 +72,7 @@ static int crypto_pcbc_encrypt_inplace(struct skcipher_request *req,
int bsize = crypto_cipher_blocksize(tfm);
unsigned int nbytes = walk->nbytes;
u8 *src = walk->src.virt.addr;
- u8 *iv = walk->iv;
+ u8 * const iv = walk->iv;
u8 tmpbuf[MAX_CIPHER_BLOCKSIZE];
do {
@@ -84,8 +84,6 @@ static int crypto_pcbc_encrypt_inplace(struct skcipher_request *req,
src += bsize;
} while ((nbytes -= bsize) >= bsize);
- memcpy(walk->iv, iv, bsize);
-
return nbytes;
}
@@ -121,7 +119,7 @@ static int crypto_pcbc_decrypt_segment(struct skcipher_request *req,
unsigned int nbytes = walk->nbytes;
u8 *src = walk->src.virt.addr;
u8 *dst = walk->dst.virt.addr;
- u8 *iv = walk->iv;
+ u8 * const iv = walk->iv;
do {
crypto_cipher_decrypt_one(tfm, dst, src);
@@ -132,8 +130,6 @@ static int crypto_pcbc_decrypt_segment(struct skcipher_request *req,
dst += bsize;
} while ((nbytes -= bsize) >= bsize);
- memcpy(walk->iv, iv, bsize);
-
return nbytes;
}
@@ -144,7 +140,7 @@ static int crypto_pcbc_decrypt_inplace(struct skcipher_request *req,
int bsize = crypto_cipher_blocksize(tfm);
unsigned int nbytes = walk->nbytes;
u8 *src = walk->src.virt.addr;
- u8 *iv = walk->iv;
+ u8 * const iv = walk->iv;
u8 tmpbuf[MAX_CIPHER_BLOCKSIZE] __aligned(__alignof__(u32));
do {
@@ -156,8 +152,6 @@ static int crypto_pcbc_decrypt_inplace(struct skcipher_request *req,
src += bsize;
} while ((nbytes -= bsize) >= bsize);
- memcpy(walk->iv, iv, bsize);
-
return nbytes;
}