CVE-2024-46798

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 bug happens only if system suspended.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

To mitigate this issue, prevent module snd-soc-core from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.