diff mbox series

[5.10,104/188] xfrm: Fix NULL pointer dereference on policy lookup

Message ID 20210412084017.108022670@linuxfoundation.org
State New
Headers show
Series None | expand

Commit Message

Greg Kroah-Hartman April 12, 2021, 8:40 a.m. UTC 
From: Steffen Klassert <steffen.klassert@secunet.com>

[ Upstream commit b1e3a5607034aa0a481c6f69a6893049406665fb ]

When xfrm interfaces are used in combination with namespaces
and ESP offload, we get a dst_entry NULL pointer dereference.
This is because we don't have a dst_entry attached in the ESP
offloading case and we need to do a policy lookup before the
namespace transition.

Fix this by expicit checking of skb_dst(skb) before accessing it.

Fixes: f203b76d78092 ("xfrm: Add virtual xfrm interfaces")
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 include/net/xfrm.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index bfbc7810df94..c58a6d4eb610 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -1097,7 +1097,7 @@  static inline int __xfrm_policy_check2(struct sock *sk, int dir,
 		return __xfrm_policy_check(sk, ndir, skb, family);
 
 	return	(!net->xfrm.policy_count[dir] && !secpath_exists(skb)) ||
-		(skb_dst(skb)->flags & DST_NOPOLICY) ||
+		(skb_dst(skb) && (skb_dst(skb)->flags & DST_NOPOLICY)) ||
 		__xfrm_policy_check(sk, ndir, skb, family);
 }