From: Eric Biggers ebiggers@google.com

The ->digest() method of crct10dif-generic reads the current CRC value from the shash_desc context. But this value is uninitialized, causing crypto_shash_digest() to compute the wrong result. Fix it.

Probably this wasn't noticed before because lib/crc-t10dif.c only uses crypto_shash_update(), not crypto_shash_digest(). Likewise, crypto_shash_digest() is not yet tested by the crypto self-tests because those only test the ahash API which only uses shash init/update/final.

This bug was detected by my patches that improve testmgr to fuzz algorithms against their generic implementation.

Fixes: 2d31e518a428 ("crypto: crct10dif - Wrap crc_t10dif function all to use crypto transform framework") Cc: stable@vger.kernel.org # v3.11+ Cc: Tim Chen tim.c.chen@linux.intel.com Signed-off-by: Eric Biggers ebiggers@google.com --- crypto/crct10dif_generic.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/crypto/crct10dif_generic.c b/crypto/crct10dif_generic.c index 8e94e29dc6fc8..d08048ae55527 100644 --- a/crypto/crct10dif_generic.c +++ b/crypto/crct10dif_generic.c @@ -65,10 +65,9 @@ static int chksum_final(struct shash_desc *desc, u8 *out) return 0; }

-static int __chksum_finup(__u16 *crcp, const u8 *data, unsigned int len, - u8 *out) +static int __chksum_finup(__u16 crc, const u8 *data, unsigned int len, u8 *out) { - *(__u16 *)out = crc_t10dif_generic(*crcp, data, len); + *(__u16 *)out = crc_t10dif_generic(crc, data, len); return 0; }

@@ -77,15 +76,13 @@ static int chksum_finup(struct shash_desc *desc, const u8 *data, { struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);

- return __chksum_finup(&ctx->crc, data, len, out); + return __chksum_finup(ctx->crc, data, len, out); }

static int chksum_digest(struct shash_desc *desc, const u8 *data, unsigned int length, u8 *out) { - struct chksum_desc_ctx *ctx = shash_desc_ctx(desc); - - return __chksum_finup(&ctx->crc, data, length, out); + return __chksum_finup(0, data, length, out); }

static struct shash_alg alg = {