kernel/1209-net-sched-act-csum-validate-nested-vlan-headers.patch
Andrew Lukoshko b9d46fff46 Recreate RHEL 6.12.0-211.18.1 from CS10/upstream backports
Add the RHEL 211.17.1..211.18.1 backports (1162-1244) from centos-stream-10 and
upstream, on top of 211.16.1. Includes the lpfc 14.4.0.x revert batch and the
RHEL-only lpfc_nlp_get UAF guard. Bump to 211.18.1.
2026-06-07 00:04:03 +00:00

56 lines
2.2 KiB
Diff

From a69738efea0996d05a3c7d2178551b891744df1b Mon Sep 17 00:00:00 2001
From: Ruide Cao <caoruide123@gmail.com>
Date: Thu, 2 Apr 2026 22:46:20 +0800
Subject: [PATCH] net: sched: act_csum: validate nested VLAN headers
[ Upstream commit c842743d073bdd683606cb414eb0ca84465dd834 ]
tcf_csum_act() walks nested VLAN headers directly from skb->data when an
skb still carries in-payload VLAN tags. The current code reads
vlan->h_vlan_encapsulated_proto and then pulls VLAN_HLEN bytes without
first ensuring that the full VLAN header is present in the linear area.
If only part of an inner VLAN header is linearized, accessing
h_vlan_encapsulated_proto reads past the linear area, and the following
skb_pull(VLAN_HLEN) may violate skb invariants.
Fix this by requiring pskb_may_pull(skb, VLAN_HLEN) before accessing and
pulling each nested VLAN header. If the header still is not fully
available, drop the packet through the existing error path.
Fixes: 2ecba2d1e45b ("net: sched: act_csum: Fix csum calc for tagged packets")
Reported-by: Yifan Wu <yifanwucs@gmail.com>
Reported-by: Juefei Pu <tomapufckgml@gmail.com>
Co-developed-by: Yuan Tan <yuantan098@gmail.com>
Signed-off-by: Yuan Tan <yuantan098@gmail.com>
Suggested-by: Xin Liu <bird@lzu.edu.cn>
Tested-by: Ren Wei <enjou1224z@gmail.com>
Signed-off-by: Ruide Cao <caoruide123@gmail.com>
Signed-off-by: Ren Wei <n05ec@lzu.edu.cn>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/22df2fcb49f410203eafa5d97963dd36089f4ecf.1774892775.git.caoruide123@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
diff --git a/net/sched/act_csum.c b/net/sched/act_csum.c
index 5cc8e407e791..8ea37c2c3c54 100644
--- a/net/sched/act_csum.c
+++ b/net/sched/act_csum.c
@@ -603,8 +603,12 @@ TC_INDIRECT_SCOPE int tcf_csum_act(struct sk_buff *skb,
protocol = skb->protocol;
orig_vlan_tag_present = true;
} else {
- struct vlan_hdr *vlan = (struct vlan_hdr *)skb->data;
+ struct vlan_hdr *vlan;
+ if (!pskb_may_pull(skb, VLAN_HLEN))
+ goto drop;
+
+ vlan = (struct vlan_hdr *)skb->data;
protocol = vlan->h_vlan_encapsulated_proto;
skb_pull(skb, VLAN_HLEN);
skb_reset_network_header(skb);
--
2.50.1 (Apple Git-155)