From: Eric Biggers ebiggers@google.com
commit 251b7aea34ba3c4d4fdfa9447695642eb8b8b098 upstream
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 Signed-off-by: Maxim Zhukov mussitantesmortem@gmail.com --- crypto/pcbc.c | 14 ++++---------- 1 file changed, 4 insertions(+), 10 deletions(-)
diff --git a/crypto/pcbc.c b/crypto/pcbc.c index d9e45a958720..67009a532201 100644 --- a/crypto/pcbc.c +++ b/crypto/pcbc.c @@ -50,7 +50,7 @@ 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); @@ -71,7 +71,7 @@ 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[bsize];
do { @@ -83,8 +83,6 @@ static int crypto_pcbc_encrypt_inplace(struct skcipher_request *req, src += bsize; } while ((nbytes -= bsize) >= bsize);
- memcpy(walk->iv, iv, bsize); - return nbytes; }
@@ -120,7 +118,7 @@ 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); @@ -131,8 +129,6 @@ static int crypto_pcbc_decrypt_segment(struct skcipher_request *req, dst += bsize; } while ((nbytes -= bsize) >= bsize);
- memcpy(walk->iv, iv, bsize); - return nbytes; }
@@ -143,7 +139,7 @@ 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[bsize] __aligned(__alignof__(u32));
do { @@ -155,8 +151,6 @@ static int crypto_pcbc_decrypt_inplace(struct skcipher_request *req, src += bsize; } while ((nbytes -= bsize) >= bsize);
- memcpy(walk->iv, iv, bsize); - return nbytes; }