ASoC: core: Fix use-after-free in snd_soc_exit()
authorChen Zhongjin <chenzhongjin@huawei.com>
Fri, 28 Oct 2022 03:16:03 +0000 (11:16 +0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sat, 26 Nov 2022 08:24:34 +0000 (09:24 +0100)
commit34eee4189bcebbd5f6a2ff25ef0cb893ad33d51e
tree6704a6675972f5757b8b73720cefbeec0c850ab4
parentaa6f8aecbbf23923cd7f17251f06fc4e52eacc8d
ASoC: core: Fix use-after-free in snd_soc_exit()

[ Upstream commit 6ec27c53886c8963729885bcf2dd996eba2767a7 ]

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:
<TASK>
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
...
</TASK>

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.

Fixes: fb257897bf20 ("ASoC: Work around allmodconfig failure")
Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
Link: https://lore.kernel.org/r/20221028031603.59416-1-chenzhongjin@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
sound/soc/soc-core.c