crypto: ahash - Fix early termination in hash walk

commit 900a081f6912a8985dc15380ec912752cb66025a upstream.

When we have an unaligned SG list entry where there is no leftover
aligned data, the hash walk code will incorrectly return zero as if
the entire SG list has been processed.

This patch fixes it by moving onto the next page instead.

Reported-by: Eli Cooper <elicooper@gmx.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/crypto/ahash.c b/crypto/ahash.c
index f75b5c1f71521c5ee73ff9137fc2242338708726..3980e9e45289e6639ab82e23072fca60d210759c 100644 (file)
--- a/crypto/ahash.c
+++ b/crypto/ahash.c
@@ -92,13 +92,14 @@ int crypto_hash_walk_done(struct crypto_hash_walk *walk, int err)
 
        if (nbytes && walk->offset & alignmask && !err) {
                walk->offset = ALIGN(walk->offset, alignmask + 1);
-               walk->data += walk->offset;
-
                nbytes = min(nbytes,
                             ((unsigned int)(PAGE_SIZE)) - walk->offset);
                walk->entrylen -= nbytes;
 
-               return nbytes;
+               if (nbytes) {
+                       walk->data += walk->offset;
+                       return nbytes;
+               }
        }
 
        if (walk->flags & CRYPTO_ALG_ASYNC)