linux-cve-announce - CVE-2025-39698: io_uring/futex: ensure io_futex

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: <2025090548-CVE-2025-39698-41e0@gregkh>
Date: Fri,  5 Sep 2025 19:21:11 +0200
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-cve-announce@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...nel.org>
Subject: CVE-2025-39698: io_uring/futex: ensure io_futex_wait() cleans up properly on failure

From: Greg Kroah-Hartman <gregkh@...nel.org>

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

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

io_uring/futex: ensure io_futex_wait() cleans up properly on failure

The io_futex_data is allocated upfront and assigned to the io_kiocb
async_data field, but the request isn't marked with REQ_F_ASYNC_DATA
at that point. Those two should always go together, as the flag tells
io_uring whether the field is valid or not.

Additionally, on failure cleanup, the futex handler frees the data but
does not clear ->async_data. Clear the data and the flag in the error
path as well.

Thanks to Trend Micro Zero Day Initiative and particularly ReDress for
reporting this.

The Linux kernel CVE team has assigned CVE-2025-39698 to this issue.


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

	Issue introduced in 6.7 with commit 194bb58c6090e39bd7d9b9c888a079213628e1f6 and fixed in 6.12.44 with commit d9f93172820a53ab42c4b0e5e65291f4f9d00ad2
	Issue introduced in 6.7 with commit 194bb58c6090e39bd7d9b9c888a079213628e1f6 and fixed in 6.16.4 with commit d34c04152df517c59979b4bf2a47f491e06d3256
	Issue introduced in 6.7 with commit 194bb58c6090e39bd7d9b9c888a079213628e1f6 and fixed in 6.17-rc3 with commit 508c1314b342b78591f51c4b5dadee31a88335df

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-2025-39698
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/futex.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/d9f93172820a53ab42c4b0e5e65291f4f9d00ad2
	https://git.kernel.org/stable/c/d34c04152df517c59979b4bf2a47f491e06d3256
	https://git.kernel.org/stable/c/508c1314b342b78591f51c4b5dadee31a88335df