This is a note to let you know that I've just added the patch titled
xfrm: Fix NULL pointer dereference on policy lookup
to the 5.11-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
xfrm-fix-null-pointer-dereference-on-policy-lookup.patch
and it can be found in the queue-5.11 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 0d732a45102674ee73a65754cc0a339f33264763
Author: Steffen Klassert <steffen.klassert@xxxxxxxxxxx>
Date: Tue Mar 23 09:26:44 2021 +0100
xfrm: Fix NULL pointer dereference on policy lookup
[ 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@xxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
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);
}
