From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-cve-announce@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@kernel.org>
Subject: CVE-2026-74473: vxlan: use pskb_network_may_pull() in route_shortcircuit()
Date: Sat, 15 Aug 2026 21:25:54 +0900 [thread overview]
Message-ID: <2026081535-CVE-2026-74473-9c71@gregkh> (raw)
From: Greg Kroah-Hartman <gregkh@kernel.org>
Description
===========
In the Linux kernel, the following vulnerability has been resolved:
vxlan: use pskb_network_may_pull() in route_shortcircuit()
route_shortcircuit() currently calls pskb_may_pull(skb, sizeof(struct iphdr))
(or ipv6hdr), which checks if bytes are available starting from skb->data.
However, in vxlan_xmit(), skb->data points to the MAC header, so
skb_network_offset(skb) is ETH_HLEN (14 bytes). Using pskb_may_pull(skb, 20)
only checks 20 bytes from skb->data (which is 14 bytes MAC header + 6 bytes of
IP header), leaving the rest of the IP header potentially un-pulled in non-linear
frags. Subsequent dereferences of ip_hdr(skb)->daddr can read beyond the pulled
linear buffer length.
Fix this by using pskb_network_may_pull(), which adds skb_network_offset(skb) to
the length check to ensure the full network header is present in the linear buffer.
The Linux kernel CVE team has assigned CVE-2026-74473 to this issue.
Affected and fixed versions
===========================
Issue introduced in 3.8 with commit e4f67addf158f98f8197e08974966b18480dc751 and fixed in 6.6.151 with commit 42887be7c4cf283cce02cd0fb6411221167c8b6c
Issue introduced in 3.8 with commit e4f67addf158f98f8197e08974966b18480dc751 and fixed in 6.12.103 with commit aa0d31376d574ac858a40078431a77127bf04ee4
Issue introduced in 3.8 with commit e4f67addf158f98f8197e08974966b18480dc751 and fixed in 6.18.44 with commit ee799977d7941dbfb11049e17edd9eaf4f8820f7
Issue introduced in 3.8 with commit e4f67addf158f98f8197e08974966b18480dc751 and fixed in 7.1.8 with commit 4f3f96e771a20263635bb5e1307c112d613b4bbd
Issue introduced in 3.8 with commit e4f67addf158f98f8197e08974966b18480dc751 and fixed in 7.2-rc6 with commit 26bb2dd0a8839617e2c79ffbbe1923f8e4bab9fb
Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.
Unaffected versions might change over time as fixes are backported to
older supported kernel versions. The official CVE entry at
https://cve.org/CVERecord/?id=CVE-2026-74473
will be updated if fixes are backported, please check that for the most
up to date information about this issue.
Affected files
==============
The file(s) affected by this issue are:
drivers/net/vxlan/vxlan_core.c
Mitigation
==========
The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes. Individual
changes are never tested alone, but rather are part of a larger kernel
release. Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all. If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
https://git.kernel.org/stable/c/42887be7c4cf283cce02cd0fb6411221167c8b6c
https://git.kernel.org/stable/c/aa0d31376d574ac858a40078431a77127bf04ee4
https://git.kernel.org/stable/c/ee799977d7941dbfb11049e17edd9eaf4f8820f7
https://git.kernel.org/stable/c/4f3f96e771a20263635bb5e1307c112d613b4bbd
https://git.kernel.org/stable/c/26bb2dd0a8839617e2c79ffbbe1923f8e4bab9fb
reply other threads:[~2026-08-15 12:28 UTC|newest]
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