This is a note to let you know that I've just added the patch titled ASoC: core: Fix use-after-free in snd_soc_exit() to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: asoc-core-fix-use-after-free-in-snd_soc_exit.patch and it can be found in the queue-4.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 792a4d5b82e4b3e9853fd722c2153a21fecb642b Author: Chen Zhongjin <chenzhongjin@xxxxxxxxxx> Date: Fri Oct 28 11:16:03 2022 +0800 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@xxxxxxxxxx> Link: https://lore.kernel.org/r/20221028031603.59416-1-chenzhongjin@xxxxxxxxxx Signed-off-by: Mark Brown <broonie@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c index febf2b649b96..b29c5a09267e 100644 --- a/sound/soc/soc-core.c +++ b/sound/soc/soc-core.c @@ -4376,10 +4376,23 @@ EXPORT_SYMBOL_GPL(snd_soc_of_get_dai_link_codecs); static int __init snd_soc_init(void) { + int ret; + snd_soc_debugfs_init(); - snd_soc_util_init(); + ret = snd_soc_util_init(); + if (ret) + goto err_util_init; - return platform_driver_register(&soc_driver); + ret = platform_driver_register(&soc_driver); + if (ret) + goto err_register; + return 0; + +err_register: + snd_soc_util_exit(); +err_util_init: + snd_soc_debugfs_exit(); + return ret; } module_init(snd_soc_init);