crypto: ahash - fix another early termination in hash walk (77568e53) · Commits · 戴 / test

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: ("crypto: ahash - Fix early termination in hash walk") Cc: stable@vger.kernel.org Signed-off-by:

Eric Biggers <ebiggers@google.com> Signed-off-by:

Herbert Xu <herbert@gondor.apana.org.au>

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);

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