diff options
| author | Herbert Xu <herbert@gondor.apana.org.au> | 2017-10-09 23:30:02 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-10-18 09:38:28 +0200 |
| commit | 05f9b8bfea4fd91c76eac398f407a2bc0920e547 (patch) | |
| tree | 040a9ae6b0e103c68dd19160a2681e2a4c8441b4 /crypto | |
| parent | 9ace51c5b4796927909be31e231fd7780c988382 (diff) | |
crypto: shash - Fix zero-length shash ahash digest crash
commit b61907bb42409adf9b3120f741af7c57dd7e3db2 upstream.
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.
Reported-by: Stephan Müller<smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Tested-by: Stephan Müller <smueller@chronox.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'crypto')
| -rw-r--r-- | crypto/shash.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/crypto/shash.c b/crypto/shash.c index 5e31c8d776df..f4161f3cfed6 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)); |