From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-cve-announce@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@kernel.org>
Subject: CVE-2026-43502: net/rds: handle zerocopy send cleanup before the message is queued
Date: Thu, 21 May 2026 14:18:02 +0200 [thread overview]
Message-ID: <2026052159-CVE-2026-43502-01ec@gregkh> (raw)
From: Greg Kroah-Hartman <gregkh@kernel.org>
Description
===========
In the Linux kernel, the following vulnerability has been resolved:
net/rds: handle zerocopy send cleanup before the message is queued
A zerocopy send can fail after user pages have been pinned but before
the message is attached to the sending socket.
The purge path currently infers zerocopy state from rm->m_rs, so an
unqueued message can be cleaned up as if it owned normal payload pages.
However, zerocopy ownership is really determined by the presence of
op_mmp_znotifier, regardless of whether the message has reached the
socket queue.
Capture op_mmp_znotifier up front in rds_message_purge() and use it as
the cleanup discriminator. If the message is already associated with a
socket, keep the existing completion path. Otherwise, drop the pinned
page accounting directly and release the notifier before putting the
payload pages.
This keeps early send failure cleanup consistent with the zerocopy
lifetime rules without changing the normal queued completion path.
The Linux kernel CVE team has assigned CVE-2026-43502 to this issue.
Affected and fixed versions
===========================
Issue introduced in 4.17 with commit 0cebaccef3acbdfbc2d85880a2efb765d2f4e2e3 and fixed in 6.6.140 with commit 21d70744e6d3bbf9293aa1ee6fba7c53ad75275e
Issue introduced in 4.17 with commit 0cebaccef3acbdfbc2d85880a2efb765d2f4e2e3 and fixed in 6.12.88 with commit 3abc8983b2bae3f487f77d9da5527d7d6b210d46
Issue introduced in 4.17 with commit 0cebaccef3acbdfbc2d85880a2efb765d2f4e2e3 and fixed in 6.18.30 with commit 14ef6fd18db2494098b21e0471bf27a1d8e9993e
Issue introduced in 4.17 with commit 0cebaccef3acbdfbc2d85880a2efb765d2f4e2e3 and fixed in 7.0.7 with commit 0f5c185fc79a59ee9991234dd6d2a3e5afa6e75b
Issue introduced in 4.17 with commit 0cebaccef3acbdfbc2d85880a2efb765d2f4e2e3 and fixed in 7.1-rc3 with commit 44b550d88b267320459d518c0743a241ab2108fa
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-2026-43502
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:
net/rds/message.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/21d70744e6d3bbf9293aa1ee6fba7c53ad75275e
https://git.kernel.org/stable/c/3abc8983b2bae3f487f77d9da5527d7d6b210d46
https://git.kernel.org/stable/c/14ef6fd18db2494098b21e0471bf27a1d8e9993e
https://git.kernel.org/stable/c/0f5c185fc79a59ee9991234dd6d2a3e5afa6e75b
https://git.kernel.org/stable/c/44b550d88b267320459d518c0743a241ab2108fa
reply other threads:[~2026-05-21 12:18 UTC|newest]
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