CVE-2026-64485: ALSA: compress: Fix task creation error unwind

From: Greg Kroah-Hartman <[email protected]>

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

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

ALSA: compress: Fix task creation error unwind

snd_compr_task_new() allocates the driver task before validating the
returned DMA buffers and reserving file descriptors. When either of
those later steps fails, the core frees its task wrapper and DMA-buffer
references without calling the driver's task_free() callback. Any
driver resources allocated by task_create() are therefore leaked.

The dual-fd allocation path also jumps to cleanup without storing the
negative get_unused_fd_flags() result in retval. Since retval still
contains the successful task_create() return value, TASK_CREATE can
incorrectly report success although the task was discarded.

Preserve the fd allocation errors and call task_free() when failure
occurs after a successful task_create() callback.

The Linux kernel CVE team has assigned CVE-2026-64485 to this issue.


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

	Issue introduced in 6.13 with commit 04177158cf98a79744937893b100020d77e6f9ac and fixed in 6.18.39 with commit b27a75d42044d9d4709095617730b91b1c4af423
	Issue introduced in 6.13 with commit 04177158cf98a79744937893b100020d77e6f9ac and fixed in 7.1.4 with commit 426a9947a38d272d0e19c031658da68e31128667
	Issue introduced in 6.13 with commit 04177158cf98a79744937893b100020d77e6f9ac and fixed in 7.2-rc1 with commit 4a60127debb9e370d6c0e22a307326b624a141f3

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-2026-64485
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/core/compress_offload.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/b27a75d42044d9d4709095617730b91b1c4af423
	https://git.kernel.org/stable/c/426a9947a38d272d0e19c031658da68e31128667
	https://git.kernel.org/stable/c/4a60127debb9e370d6c0e22a307326b624a141f3