From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-cve-announce@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@kernel.org>
Subject: CVE-2026-68142: geneve: require CAP_NET_ADMIN in the device netns for changelink
Date: Mon, 10 Aug 2026 13:57:39 +0200 [thread overview]
Message-ID: <2026081000-CVE-2026-68142-3fc3@gregkh> (raw)
From: Greg Kroah-Hartman <gregkh@kernel.org>
Description
===========
In the Linux kernel, the following vulnerability has been resolved:
geneve: require CAP_NET_ADMIN in the device netns for changelink
A tunnel changelink() operates on at most two netns, dev_net(dev) and
the sticky underlay netns geneve->net. They differ once the device is
created in or moved to a netns other than the one the request runs in.
The rtnl changelink path checks CAP_NET_ADMIN only against dev_net(dev),
so a caller privileged there but not in geneve->net can rewrite a geneve
device whose underlay lives in geneve->net.
geneve_changelink() applies the new configuration against geneve->net:
geneve_link_config() and the geneve_quiesce()/geneve_unquiesce() pair
reopen the underlay sockets in that netns (geneve_sock_add() uses
geneve->net), so the same reasoning as the tunnel changelink series
applies here.
Gate geneve_changelink() with rtnl_dev_link_net_capable(), at the top of
the op before any attribute is parsed, matching ipgre_changelink() and
the rest of the "require CAP_NET_ADMIN in the device netns for
changelink" series.
Found by 0sec automated security-research tooling (https://0sec.ai).
The Linux kernel CVE team has assigned CVE-2026-68142 to this issue.
Affected and fixed versions
===========================
Issue introduced in 4.14 with commit 5b861f6baa3a22a48d7a4ad0ce38a223d36c978a and fixed in 6.6.148 with commit 2abdacc927c92fa6a9cc8341e8c9b88dcb561553
Issue introduced in 4.14 with commit 5b861f6baa3a22a48d7a4ad0ce38a223d36c978a and fixed in 6.12.101 with commit 9de5518fc1fab583526a8f66b8e505c4864dc60a
Issue introduced in 4.14 with commit 5b861f6baa3a22a48d7a4ad0ce38a223d36c978a and fixed in 6.18.42 with commit f8c498585d2a08aa623748353c3e61467b7e9fd2
Issue introduced in 4.14 with commit 5b861f6baa3a22a48d7a4ad0ce38a223d36c978a and fixed in 7.1.6 with commit 95f45e20f1b2cec13823f0f68060ab4b2261b2c1
Issue introduced in 4.14 with commit 5b861f6baa3a22a48d7a4ad0ce38a223d36c978a and fixed in 7.2-rc5 with commit 8efb8f8bbb353b8f2fdf4f37534c6d96c9f69e01
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-2026-68142
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/geneve.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/2abdacc927c92fa6a9cc8341e8c9b88dcb561553
https://git.kernel.org/stable/c/9de5518fc1fab583526a8f66b8e505c4864dc60a
https://git.kernel.org/stable/c/f8c498585d2a08aa623748353c3e61467b7e9fd2
https://git.kernel.org/stable/c/95f45e20f1b2cec13823f0f68060ab4b2261b2c1
https://git.kernel.org/stable/c/8efb8f8bbb353b8f2fdf4f37534c6d96c9f69e01
reply other threads:[~2026-08-10 12:03 UTC|newest]
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