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From: Steffen Klassert <steffen.klassert@secunet.com>
To: David Miller <davem@davemloft.net>, Jakub Kicinski <kuba@kernel.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>,
	Steffen Klassert <steffen.klassert@secunet.com>,
	<netdev@vger.kernel.org>
Subject: [PATCH 09/11] xfrm: Fix NULL pointer dereference on policy lookup
Date: Wed, 31 Mar 2021 10:18:45 +0200	[thread overview]
Message-ID: <20210331081847.3547641-10-steffen.klassert@secunet.com> (raw)
In-Reply-To: <20210331081847.3547641-1-steffen.klassert@secunet.com>

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>
---
 include/net/xfrm.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

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);
 }
 
-- 
2.25.1


  parent reply	other threads:[~2021-03-31  8:19 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-31  8:18 pull request (net): ipsec 2021-03-31 Steffen Klassert
2021-03-31  8:18 ` [PATCH 01/11] xfrm: interface: fix ipv4 pmtu check to honor ip header df Steffen Klassert
2021-03-31 22:00   ` patchwork-bot+netdevbpf
2021-03-31  8:18 ` [PATCH 02/11] vti: " Steffen Klassert
2021-03-31  8:18 ` [PATCH 03/11] vti6: " Steffen Klassert
2021-03-31  8:18 ` [PATCH 04/11] xfrm: Use actual socket sk instead of skb socket for xfrm_output_resume Steffen Klassert
2021-03-31  8:18 ` [PATCH 05/11] net: xfrm: Localize sequence counter per network namespace Steffen Klassert
2021-03-31  8:18 ` [PATCH 06/11] net: xfrm: Use sequence counter with associated spinlock Steffen Klassert
2021-03-31  8:18 ` [PATCH 07/11] esp: delete NETIF_F_SCTP_CRC bit from features for esp offload Steffen Klassert
2021-03-31  8:18 ` [PATCH 08/11] xfrm: BEET mode doesn't support fragments for inner packets Steffen Klassert
2021-03-31  8:18 ` Steffen Klassert [this message]
2021-03-31  8:18 ` [PATCH 10/11] xfrm: Provide private skb extensions for segmented and hw offloaded ESP packets Steffen Klassert
2021-03-31  8:18 ` [PATCH 11/11] xfrm/compat: Cleanup WARN()s that can be user-triggered Steffen Klassert
2021-03-31 22:00 ` pull request (net): ipsec 2021-03-31 patchwork-bot+netdevbpf

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