From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-cve-announce@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@kernel.org>
Subject: CVE-2026-99266: io_uring/zcrx: fix buffer offsets in areas above 4GB
Date: Tue, 3 Nov 2026 12:48:26 +0100 [thread overview]
Message-ID: <2026110325-CVE-2026-99266-e63b@gregkh> (raw)
From: Greg Kroah-Hartman <gregkh@kernel.org>
Description
===========
In the Linux kernel, the following vulnerability has been resolved:
io_uring/zcrx: fix buffer offsets in areas above 4GB
io_zcrx_queue_cqe() computes the offset of the buffer in its area from
net_iov_idx(), which is an unsigned int, so the shift is done in 32 bits
and only the result is widened to the u64 that goes into the CQE. An area
can be up to 1TB in size. For every niov beyond the first 4GB the CQE
points the application at a buffer 4GB, or a multiple of that, below the
one which has the data. It reads the wrong data, and then returns a
buffer it doesn't own via the refill queue while the real one is never
given back.
The Linux kernel CVE team has assigned CVE-2026-99266 to this issue.
Affected and fixed versions
===========================
Issue introduced in 6.15 with commit 11ed914bbf948c4a37248f2876973ac18014056d and fixed in 6.18.60 with commit 9bfb315e2d0907fbcaf5d0453dd6d873c9aa8d5b
Issue introduced in 6.15 with commit 11ed914bbf948c4a37248f2876973ac18014056d and fixed in 7.2.14 with commit 51f4ee29bf0564e6ae7d3540693a9bc1dd2c8fd7
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-2026-99266
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:
io_uring/zcrx.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/9bfb315e2d0907fbcaf5d0453dd6d873c9aa8d5b
https://git.kernel.org/stable/c/51f4ee29bf0564e6ae7d3540693a9bc1dd2c8fd7
https://git.kernel.org/stable/c/ab4536bf2e5617b04f2d9396f06393c7bbfb071d
reply other threads:[~2026-11-03 11:50 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=2026110325-CVE-2026-99266-e63b@gregkh \
--to=gregkh@linuxfoundation.org \
--cc=cve@kernel.org \
--cc=gregkh@kernel.org \
--cc=linux-cve-announce@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.