Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 77568e53 authored by Eric Biggers's avatar Eric Biggers Committed by Herbert Xu
Browse files

crypto: ahash - fix another early termination in hash walk 



Hash algorithms with an alignmask set, e.g. "xcbc(aes-aesni)" and
"michael_mic", fail the improved hash tests because they sometimes
produce the wrong digest.  The bug is that in the case where a
scatterlist element crosses pages, not all the data is actually hashed
because the scatterlist walk terminates too early.  This happens because
the 'nbytes' variable in crypto_hash_walk_done() is assigned the number
of bytes remaining in the page, then later interpreted as the number of
bytes remaining in the scatterlist element.  Fix it.

Fixes: 900a081f ("crypto: ahash - Fix early termination in hash walk")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 3af34963

crypto/ahash.c

+7 −7
Original line number Diff line number Diff line
@@ -86,17 +86,17 @@ static int hash_walk_new_entry(struct crypto_hash_walk *walk) 
int crypto_hash_walk_done(struct crypto_hash_walk *walk, int err)

{

	unsigned int alignmask = walk->alignmask;

	unsigned int nbytes = walk->entrylen;



	walk->data -= walk->offset;



	if (nbytes && walk->offset & alignmask && !err) {

		walk->offset = ALIGN(walk->offset, alignmask + 1);

		nbytes = min(nbytes,

			     ((unsigned int)(PAGE_SIZE)) - walk->offset);

		walk->entrylen -= nbytes;

	if (walk->entrylen && (walk->offset & alignmask) && !err) {

		unsigned int nbytes;



		walk->offset = ALIGN(walk->offset, alignmask + 1);

		nbytes = min(walk->entrylen,

			     (unsigned int)(PAGE_SIZE - walk->offset));

		if (nbytes) {

			walk->entrylen -= nbytes;

			walk->data += walk->offset;

			return nbytes;

		}
@@ -116,7 +116,7 @@ int crypto_hash_walk_done(struct crypto_hash_walk *walk, int err) 
	if (err)

		return err;



	if (nbytes) {

	if (walk->entrylen) {

		walk->offset = 0;

		walk->pg++;

		return hash_walk_next(walk);