From: Steffen Klassert <steffen.klassert@secunet.com>
To: David Miller <davem@davemloft.net>
Cc: Herbert Xu <herbert@gondor.apana.org.au>,
Steffen Klassert <steffen.klassert@secunet.com>,
<netdev@vger.kernel.org>
Subject: [PATCH 3/4] vti: fix NULL dereference in xfrm_input()
Date: Mon, 9 Oct 2017 09:16:38 +0200 [thread overview]
Message-ID: <1507533399-29399-4-git-send-email-steffen.klassert@secunet.com> (raw)
In-Reply-To: <1507533399-29399-1-git-send-email-steffen.klassert@secunet.com>
From: Alexey Kodanev <alexey.kodanev@oracle.com>
Can be reproduced with LTP tests:
# icmp-uni-vti.sh -p ah -a sha256 -m tunnel -S fffffffe -k 1 -s 10
IPv4:
RIP: 0010:xfrm_input+0x7f9/0x870
...
Call Trace:
<IRQ>
vti_input+0xaa/0x110 [ip_vti]
? skb_free_head+0x21/0x40
vti_rcv+0x33/0x40 [ip_vti]
xfrm4_ah_rcv+0x33/0x60
ip_local_deliver_finish+0x94/0x1e0
ip_local_deliver+0x6f/0xe0
? ip_route_input_noref+0x28/0x50
...
# icmp-uni-vti.sh -6 -p ah -a sha256 -m tunnel -S fffffffe -k 1 -s 10
IPv6:
RIP: 0010:xfrm_input+0x7f9/0x870
...
Call Trace:
<IRQ>
xfrm6_rcv_tnl+0x3c/0x40
vti6_rcv+0xd5/0xe0 [ip6_vti]
xfrm6_ah_rcv+0x33/0x60
ip6_input_finish+0xee/0x460
ip6_input+0x3f/0xb0
ip6_rcv_finish+0x45/0xa0
ipv6_rcv+0x34b/0x540
xfrm_input() invokes xfrm_rcv_cb() -> vti_rcv_cb(), the last callback
might call skb_scrub_packet(), which in turn can reset secpath.
Fix it by adding a check that skb->sp is not NULL.
Fixes: 7e9e9202bccc ("xfrm: Clear RX SKB secpath xfrm_offload")
Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
---
net/xfrm/xfrm_input.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/net/xfrm/xfrm_input.c b/net/xfrm/xfrm_input.c
index 2515cd2..8ac9d32 100644
--- a/net/xfrm/xfrm_input.c
+++ b/net/xfrm/xfrm_input.c
@@ -429,7 +429,8 @@ int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
nf_reset(skb);
if (decaps) {
- skb->sp->olen = 0;
+ if (skb->sp)
+ skb->sp->olen = 0;
skb_dst_drop(skb);
gro_cells_receive(&gro_cells, skb);
return 0;
@@ -440,7 +441,8 @@ int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
err = x->inner_mode->afinfo->transport_finish(skb, xfrm_gro || async);
if (xfrm_gro) {
- skb->sp->olen = 0;
+ if (skb->sp)
+ skb->sp->olen = 0;
skb_dst_drop(skb);
gro_cells_receive(&gro_cells, skb);
return err;
--
2.7.4
next prev parent reply other threads:[~2017-10-09 7:16 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-09 7:16 pull request (net): ipsec 2017-10-09 Steffen Klassert
2017-10-09 7:16 ` [PATCH 1/4] xfrm: Fix deletion of offloaded SAs on failure Steffen Klassert
2017-10-09 7:16 ` [PATCH 2/4] xfrm: Fix negative device refcount on offload failure Steffen Klassert
2017-10-09 7:16 ` Steffen Klassert [this message]
2017-10-09 7:16 ` [PATCH 4/4] xfrm: don't call xfrm_policy_cache_flush under xfrm_state_lock Steffen Klassert
2017-10-09 16:44 ` pull request (net): ipsec 2017-10-09 David Miller
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