On Mon, Oct 09, 2017 at 05:13:48PM +0200, Stephan Müller wrote:
> Am Montag, 9. Oktober 2017, 16:19:25 CEST schrieb Herbert Xu:
>
> Hi Herbert,
>
> > On Sat, Oct 07, 2017 at 02:56:24PM +0200, Stephan Müller wrote:
> > > Though, this opens up the shash issue I tried to fix.
> >
> > Does this patch fix the crash?
>
> I get the following during boot:
Thanks for the quick response. Obviously not doing the hash
at all isn't right.
Does this patch work better?
---8<---
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.
Cc: <sta...@vger.kernel.org>
Reported-by: Stephan Müller<smuel...@chronox.de>
Signed-off-by: Herbert Xu <herb...@gondor.apana.org.au>
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));
--
Email: Herbert Xu <herb...@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
