[PATCH 4.4 099/117] crypto: algif_skcipher - sendmsg SG marking is off by one

Greg Kroah-Hartman
2016-02-15T00:23:40Z

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

commit 202736d99b7f29279db9da61587f11a08a04a9c6 upstream.

We mark the end of the SG list in sendmsg and sendpage and unmark
it on the next send call. Unfortunately the unmarking in sendmsg
is off-by-one, leading to an SG list that is too short.

Fixes: 0f477b655a52 ("crypto: algif - Mark sgl end at the end of data")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
crypto/algif_skcipher.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/crypto/algif_skcipher.c
+++ b/crypto/algif_skcipher.c
@@ -392,7 +392,8 @@ static int skcipher_sendmsg(struct socke

sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
sg = sgl->sg;
- sg_unmark_end(sg + sgl->cur);
+ if (sgl->cur)
+ sg_unmark_end(sg + sgl->cur - 1);
do {
i = sgl->cur;
plen = min_t(int, len, PAGE_SIZE);