CVE-2022-49842 Information

May 02, 2025 cve

Description

In the Linux kernel the following vulnerability has been resolved:

ASoC: core: Fix use-after-free in snd_soc_exit()

KASAN reports a use-after-free:

BUG: KASAN: use-after-free in device_del+0xb5b/0xc60 Read of size 8 at addr ffff888008655050 by task rmmod/387 CPU: 2 PID: 387 Comm: rmmod Hardware name: QEMU Standard PC (i440FX + PIIX 1996) Call Trace: dump_stack_lvl+0x79/0x9a print_report+0x17f/0x47b kasan_report+0xbb/0xf0 device_del+0xb5b/0xc60 platform_device_del.part.0+0x24/0x200 platform_device_unregister+0x2e/0x40 snd_soc_exit+0xa/0x22 [snd_soc_core] __do_sys_delete_module.constprop.0+0x34f/0x5b0 do_syscall_64+0x3a/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd …

It’s bacause in snd_soc_init() snd_soc_util_init() is possble to fail but its ret is ignored which makes soc_dummy_dev unregistered twice.

snd_soc_init() snd_soc_util_init() platform_device_register_simple(soc_dummy_dev) platform_driver_register() fail platform_device_unregister(soc_dummy_dev) platform_driver_register() success … snd_soc_exit() snd_soc_util_exit() soc_dummy_dev will be unregistered for second time

To fix it handle error and stop snd_soc_init() when util_init() fail. Also clean debugfs when util_init() or driver_register() fail.

Reference

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