CVE-2026-46262: ASoC: fsl_xcvr: Revert fix missing lock in fsl_xcvr_mode_put()

CVE-2026-46262: ASoC: fsl_xcvr: Revert fix missing lock in fsl_xcvr_mode_put()

[Greg Kroah-Hartman]

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

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

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

ASoC: fsl_xcvr: Revert fix missing lock in fsl_xcvr_mode_put()

This reverts commit f51424872760 ("ASoC: fsl_xcvr: fix missing lock in fsl_xcvr_mode_put()").

The original patch attempted to acquire the card->controls_rwsem lock in
fsl_xcvr_mode_put(). However, this function is called from the upper ALSA
core function snd_ctl_elem_write(), which already holds the write lock on
controls_rwsem for the whole put operation. So there is no need to simply
hold the lock for fsl_xcvr_activate_ctl() again.

Acquiring the read lock while holding the write lock in the same thread
results in a deadlock and a hung task, as reported by Alexander Stein.

The Linux kernel CVE team has assigned CVE-2026-46262 to this issue.


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

	Issue introduced in 5.15.201 with commit 612ffe1f4f0499b3011f16d06e354a76dae2e2d1 and fixed in 5.15.202 with commit ae5a70e3e87c28edbaf9939cfef1bcbd9615420f
	Issue introduced in 6.1.164 with commit 38354c82abe7bcbcd1182a06af89d3cc16d3e2c7 and fixed in 6.1.165 with commit 30ffcad5edb56947dccc26f6816ab7a55b21a711
	Issue introduced in 6.6.127 with commit 61e007657bf7740d54ca2aadce0fb5997839818e and fixed in 6.6.128 with commit 29b2fbe3498da3681a01b34e4a2259f8a1b89448
	Issue introduced in 6.12.74 with commit daaf4fe333e0d48b2037cd2270bf1ff8f70d5068 and fixed in 6.12.75 with commit b0f74f5d24fe3c73ef1369a811891198b54c1e8e
	Issue introduced in 6.18.13 with commit cab928242853a832ffa7efda270ecfb9efeebb6e and fixed in 6.18.14 with commit 9a2a5da002775376498e8814df4a87cd629a3a0c
	Issue introduced in 6.19 with commit f514248727606b9087bc38a284ff686e0093abf1 and fixed in 6.19.4 with commit 0886dc6326c3cc596799c4340d342898301cf52a
	Issue introduced in 6.19 with commit f514248727606b9087bc38a284ff686e0093abf1 and fixed in 7.0 with commit 9f16d96e1222391a6b996a1b676bec14fb91e3b2

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-2026-46262
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:
	sound/soc/fsl/fsl_xcvr.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/ae5a70e3e87c28edbaf9939cfef1bcbd9615420f
	https://git.kernel.org/stable/c/30ffcad5edb56947dccc26f6816ab7a55b21a711
	https://git.kernel.org/stable/c/29b2fbe3498da3681a01b34e4a2259f8a1b89448
	https://git.kernel.org/stable/c/b0f74f5d24fe3c73ef1369a811891198b54c1e8e
	https://git.kernel.org/stable/c/9a2a5da002775376498e8814df4a87cd629a3a0c
	https://git.kernel.org/stable/c/0886dc6326c3cc596799c4340d342898301cf52a
	https://git.kernel.org/stable/c/9f16d96e1222391a6b996a1b676bec14fb91e3b2