crypto: ahash - Fix early termination in hash walk

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>

diff --git a/crypto/ahash.c b/crypto/ahash.c
index f732dd9dedf9684a09b38d51412f76d2a5b6b9c0..a64c143165b1fb3ce048b0de8f59ef5bacea077d 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)