diff options
| author | Herbert Xu <herbert@gondor.apana.org.au> | 2017-10-09 23:30:02 +0800 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2018-01-01 20:51:50 +0000 |
| commit | a5dd5f18a77ac67d640d5275e0995dba2718f8bf (patch) | |
| tree | 3c9bab3699e9df88d448336742f7080ebae3c661 /crypto | |
| parent | 48d43259944e7b2e4bf03f6eef9e437e922c95d8 (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: Ben Hutchings <ben@decadent.org.uk>
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 03fbcd4a82c4..17510eaf0a36 100644 --- a/crypto/shash.c +++ b/crypto/shash.c @@ -274,12 +274,14 @@ 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)); |