CVE-2026-98960: btrfs: don't stash io_uring encoded data across -EAGAIN

CVE-2026-98960: btrfs: don't stash io_uring encoded data across -EAGAIN

[Greg Kroah-Hartman]

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

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

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

btrfs: don't stash io_uring encoded data across -EAGAIN

Returning -EAGAIN while leaving btrfs_uring_encoded_data in the cmd PDU
leaks if the request is cancelled or the ring exits before reissue.
io_uring does not free driver PDU allocations on cleanup.

Write: io_queue_sqe() always issues with IO_URING_F_NONBLOCK first, so
return -EAGAIN before allocating and free data on every exit.

Read: free on nowait -EAGAIN too; only -EIOCBQUEUED keeps the allocation
for btrfs_uring_read_finished().

The Linux kernel CVE team has assigned CVE-2026-98960 to this issue.


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

	Issue introduced in 6.13 with commit 34310c442e175f286b4c06ab5caa4e0b267ea31c and fixed in 7.2.11 with commit 4d9c1e0a7fb2cfb1cc924acafc194d2c15c3e83e
	Issue introduced in 6.13 with commit 34310c442e175f286b4c06ab5caa4e0b267ea31c and fixed in 7.3 with commit 51562a8cb11628d3a5e105b4c347ec5473e5745f

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-2026-98960
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:
	fs/btrfs/ioctl.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/4d9c1e0a7fb2cfb1cc924acafc194d2c15c3e83e
	https://git.kernel.org/stable/c/51562a8cb11628d3a5e105b4c347ec5473e5745f