Bug 2313146 (CVE-2024-46798)

Summary:	CVE-2024-46798 kernel: ASoC: dapm: Fix UAF for snd_soc_pcm_runtime object
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	dfreiber, drow, jburrell, vkumar
Target Milestone:	---	Keywords:	Security
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Hardware:	All
OS:	Linux
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
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Bug Depends On:	2313278
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Description OSIDB Bzimport 2024-09-18 08:23:35 UTC

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.

Comment 1 Michal Findra 2024-09-18 12:32:29 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2024091856-CVE-2024-46798-ce16@gregkh/T