[PATCH 3.16 005/233] af_key: Fix slab-out-of-bounds in pfkey_compile_policy.

[Ben Hutchings]

3.16.48-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Steffen Klassert <steffen.klassert@xxxxxxxxxxx>

commit d90c902449a7561f1b1d58ba5a0d11728ce8b0b2 upstream.

The sadb_x_sec_len is stored in the unit 'byte divided by eight'.
So we have to multiply this value by eight before we can do
size checks. Otherwise we may get a slab-out-of-bounds when
we memcpy the user sec_ctx.

Fixes: df71837d502 ("[LSM-IPSec]: Security association restriction.")
Reported-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Tested-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Signed-off-by: Steffen Klassert <steffen.klassert@xxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 net/key/af_key.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/key/af_key.c
+++ b/net/key/af_key.c
@@ -3282,7 +3282,7 @@ static struct xfrm_policy *pfkey_compile
 		p += pol->sadb_x_policy_len*8;
 		sec_ctx = (struct sadb_x_sec_ctx *)p;
 		if (len < pol->sadb_x_policy_len*8 +
-		    sec_ctx->sadb_x_sec_len) {
+		    sec_ctx->sadb_x_sec_len*8) {
 			*dir = -EINVAL;
 			goto out;
 		}