From: Eva Kurchatova <eva.kurchatova@virtuozzo.com>
To: khorenko@virtuozzo.com
Cc: devel@openvz.org
Subject: [Devel] [PATCH vz10 1/7] ms/vxlan: do not reuse cached ip_hdr() value after skb_tunnel_check_pmtu()
Date: Tue, 1 Sep 2026 01:48:19 +0300 [thread overview]
Message-ID: <20260831224850.1642265-1-eva.kurchatova@virtuozzo.com> (raw)
From: Eric Dumazet <edumazet@google.com>
skb_tunnel_check_pmtu() can change skb->head.
Reusing old_iph afer skb_tunnel_check_pmtu() can cause an UAF.
Use instead ip_hdr(skb) as done in drivers/net/bareudp.c
and drivers/net/geneve.c.
Found by Sashiko.
Fixes: 4cb47a8644cc ("tunnels: PMTU discovery support for directly bridged IP packets")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Link: https://patch.msgid.link/20260525203642.2389723-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
(cherry picked from commit 7d9ef0cb271555d8cf39fefe6c981e1493b25ecf)
https://virtuozzo.atlassian.net/browse/VSTOR-139651
Feature: fix ms/net
Signed-off-by: Eva Kurchatova <eva.kurchatova@virtuozzo.com>
---
drivers/net/vxlan/vxlan_core.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/net/vxlan/vxlan_core.c b/drivers/net/vxlan/vxlan_core.c
index 7c9d2450209a..700bee7e7733 100644
--- a/drivers/net/vxlan/vxlan_core.c
+++ b/drivers/net/vxlan/vxlan_core.c
@@ -2554,7 +2554,7 @@ void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
goto out_unlock;
}
- tos = ip_tunnel_ecn_encap(tos, old_iph, skb);
+ tos = ip_tunnel_ecn_encap(tos, ip_hdr(skb), skb);
ttl = ttl ? : ip4_dst_hoplimit(&rt->dst);
err = vxlan_build_skb(skb, ndst, sizeof(struct iphdr),
vni, md, flags, udp_sum);
@@ -2623,7 +2623,7 @@ void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
goto out_unlock;
}
- tos = ip_tunnel_ecn_encap(tos, old_iph, skb);
+ tos = ip_tunnel_ecn_encap(tos, ip_hdr(skb), skb);
ttl = ttl ? : ip6_dst_hoplimit(ndst);
skb_scrub_packet(skb, xnet);
err = vxlan_build_skb(skb, ndst, sizeof(struct ipv6hdr),
--
2.55.0
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next reply other threads:[~2026-08-31 22:50 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-31 22:48 Eva Kurchatova [this message]
2026-08-31 22:48 ` [Devel] [PATCH vz10 2/7] selftests: net: run the fdb and bind tests in their own netns Eva Kurchatova
2026-08-31 22:48 ` [Devel] [PATCH vz10 3/7] selftests: net: skip what this kernel and iproute2 do not have Eva Kurchatova
2026-08-31 22:48 ` [Devel] [PATCH vz10 4/7] selftests: net: make the veth GRO checks independent of host tunnels Eva Kurchatova
2026-08-31 22:48 ` [Devel] [PATCH vz10 5/7] selftests: net: install pmtu.sh, the script pmtu_wrapper.sh runs Eva Kurchatova
2026-08-31 22:48 ` [Devel] [PATCH vz10 6/7] selftests: net: mark test_ingress_egress_chaining.sh executable Eva Kurchatova
2026-08-31 22:48 ` [Devel] [PATCH vz10 7/7] selftests: net: let the bridged PMTU tests take the ICMP they ask for Eva Kurchatova
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