linux-cve-announce - CVE-2024-56709: io_uring: check if iowq is killed before queuing

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-ID: <2024122918-CVE-2024-56709-655c@gregkh>
Date: Sun, 29 Dec 2024 09:42:19 +0100
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-cve-announce@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Subject: CVE-2024-56709: io_uring: check if iowq is killed before queuing

Description
===========

In the Linux kernel, the following vulnerability has been resolved:

io_uring: check if iowq is killed before queuing

task work can be executed after the task has gone through io_uring
termination, whether it's the final task_work run or the fallback path.
In this case, task work will find ->io_wq being already killed and
null'ed, which is a problem if it then tries to forward the request to
io_queue_iowq(). Make io_queue_iowq() fail requests in this case.

Note that it also checks PF_KTHREAD, because the user can first close
a DEFER_TASKRUN ring and shortly after kill the task, in which case
->iowq check would race.

The Linux kernel CVE team has assigned CVE-2024-56709 to this issue.


Affected and fixed versions
===========================

	Issue introduced in 5.14 with commit 773af69121ecc6c53d192661af8d53bb3db028ae and fixed in 6.1.122 with commit 534d59ab38010aada88390db65985e65d0de7d9e
	Issue introduced in 5.14 with commit 773af69121ecc6c53d192661af8d53bb3db028ae and fixed in 6.6.68 with commit 2ca94c8de36091067b9ce7527ae8db3812d38781
	Issue introduced in 5.14 with commit 773af69121ecc6c53d192661af8d53bb3db028ae and fixed in 6.12.7 with commit 4f95a2186b7f2af09331e1e8069bcaf34fe019cf
	Issue introduced in 5.14 with commit 773af69121ecc6c53d192661af8d53bb3db028ae and fixed in 6.13-rc4 with commit dbd2ca9367eb19bc5e269b8c58b0b1514ada9156

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-2024-56709
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/io_uring.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/534d59ab38010aada88390db65985e65d0de7d9e
	https://git.kernel.org/stable/c/2ca94c8de36091067b9ce7527ae8db3812d38781
	https://git.kernel.org/stable/c/4f95a2186b7f2af09331e1e8069bcaf34fe019cf
	https://git.kernel.org/stable/c/dbd2ca9367eb19bc5e269b8c58b0b1514ada9156