Message ID | 20171009153002.GA7963@gondor.apana.org.au (mailing list archive) |
---|---|
State | Accepted |
Delegated to: | Herbert Xu |
Headers | show |
Am Montag, 9. Oktober 2017, 17:30:02 CEST schrieb Herbert Xu: Hi Herbert, > The shash ahash digest adaptor function may crash if given a > zero-length input together with a null SG list. This is because > it tries to read the SG list before looking at the length. > > This patch fixes it by checking the length first. The patch fixes the issue. > > Cc: <stable@vger.kernel.org> > Reported-by: Stephan Müller<smueller@chronox.de> > Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Tested-by: Stephan Müller <smueller@chronox.de> Ciao Stephan
diff --git a/crypto/shash.c b/crypto/shash.c index 8fcecc6..325a14d 100644 --- a/crypto/shash.c +++ b/crypto/shash.c @@ -275,12 +275,14 @@ static int shash_async_finup(struct ahash_request *req) int shash_ahash_digest(struct ahash_request *req, struct shash_desc *desc) { - struct scatterlist *sg = req->src; - unsigned int offset = sg->offset; unsigned int nbytes = req->nbytes; + struct scatterlist *sg; + unsigned int offset; int err; - if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) { + if (nbytes && + (sg = req->src, offset = sg->offset, + nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset))) { void *data; data = kmap_atomic(sg_page(sg));