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| author | Eric Biggers <ebiggers@google.com> | 2019-01-03 20:16:13 -0800 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2019-01-11 14:16:57 +0800 |
| commit | 251b7aea34ba3c4d4fdfa9447695642eb8b8b098 (patch) | |
| tree | 4e2b2ce50c7f79ac784abfc4332f2301d51cf4e9 /crypto/pcbc.c | |
| parent | b3e3e2db7de4a1ffe8845876c3520b866cd48de1 (diff) | |
| download | lwn-251b7aea34ba3c4d4fdfa9447695642eb8b8b098.tar.gz lwn-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.c | 14 |
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; } |