[PATCH 3.16 193/233] xfrm: NULL dereference on allocation failure

From: Ben Hutchings
Date: Sat Sep 09 2017 - 19:04:49 EST

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


From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

commit e747f64336fc15e1c823344942923195b800aa1e upstream.

The default error code in pfkey_msg2xfrm_state() is -ENOBUFS. We
added a new call to security_xfrm_state_alloc() which sets "err" to zero
so there several places where we can return ERR_PTR(0) if kmalloc()
fails. The caller is expecting error pointers so it leads to a NULL

Fixes: df71837d5024 ("[LSM-IPSec]: Security association restriction.")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Steffen Klassert <steffen.klassert@xxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
net/key/af_key.c | 1 +
1 file changed, 1 insertion(+)

--- a/net/key/af_key.c
+++ b/net/key/af_key.c
@@ -1156,6 +1156,7 @@ static struct xfrm_state * pfkey_msg2xfr
goto out;

+ err = -ENOBUFS;
key = ext_hdrs[SADB_EXT_KEY_AUTH - 1];
if (sa->sadb_sa_auth) {
int keysize = 0;