Subject: CVE-2024-46798: ASoC: dapm: Fix UAF for snd_soc_pcm_runtime object

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

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

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

ASoC: dapm: Fix UAF for snd_soc_pcm_runtime object

When using kernel with the following extra config,

  - CONFIG_KASAN=y
  - CONFIG_KASAN_GENERIC=y
  - CONFIG_KASAN_INLINE=y
  - CONFIG_KASAN_VMALLOC=y
  - CONFIG_FRAME_WARN=4096

kernel detects that snd_pcm_suspend_all() access a freed
'snd_soc_pcm_runtime' object when the system is suspended, which
leads to a use-after-free bug:

[   52.047746] BUG: KASAN: use-after-free in snd_pcm_suspend_all+0x1a8/0x270
[   52.047765] Read of size 1 at addr ffff0000b9434d50 by task systemd-sleep/2330

[   52.047785] Call trace:
[   52.047787]  dump_backtrace+0x0/0x3c0
[   52.047794]  show_stack+0x34/0x50
[   52.047797]  dump_stack_lvl+0x68/0x8c
[   52.047802]  print_address_description.constprop.0+0x74/0x2c0
[   52.047809]  kasan_report+0x210/0x230
[   52.047815]  __asan_report_load1_noabort+0x3c/0x50
[   52.047820]  snd_pcm_suspend_all+0x1a8/0x270
[   52.047824]  snd_soc_suspend+0x19c/0x4e0

The snd_pcm_sync_stop() has a NULL check on 'substream->runtime' before
making any access. So we need to always set 'substream->runtime' to NULL
everytime we kfree() it.

The Linux kernel CVE team has assigned CVE-2024-46798 to this issue.

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

	Issue introduced in 5.4 with commit a72706ed8208 and fixed in 5.4.284 with commit 993b60c7f93f
	Issue introduced in 5.4 with commit a72706ed8208 and fixed in 5.10.226 with commit 8ca21e7a27c6
	Issue introduced in 5.4 with commit a72706ed8208 and fixed in 5.15.167 with commit 3033ed903b4f
	Issue introduced in 5.4 with commit a72706ed8208 and fixed in 6.1.110 with commit fe5046ca91d6
	Issue introduced in 5.4 with commit a72706ed8208 and fixed in 6.6.51 with commit 5d13afd021eb
	Issue introduced in 5.4 with commit a72706ed8208 and fixed in 6.10.10 with commit 6a14fad8be17
	Issue introduced in 5.4 with commit a72706ed8208 and fixed in 6.11 with commit b4a90b543d9f

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-2024-46798
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/soc-dapm.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/993b60c7f93fa1d8ff296b58f646a867e945ae89
	https://git.kernel.org/stable/c/8ca21e7a27c66b95a4b215edc8e45e5d66679f9f
	https://git.kernel.org/stable/c/3033ed903b4f28b5e1ab66042084fbc2c48f8624
	https://git.kernel.org/stable/c/fe5046ca91d631ec432eee3bdb1f1c49b09c8b5e
	https://git.kernel.org/stable/c/5d13afd021eb43868fe03cef6da34ad08831ad6d
	https://git.kernel.org/stable/c/6a14fad8be178df6c4589667efec1789a3307b4e
	https://git.kernel.org/stable/c/b4a90b543d9f62d3ac34ec1ab97fc5334b048565