• Chen Zhongjin's avatar
    ASoC: core: Fix use-after-free in snd_soc_exit() · 6ec27c53
    Chen Zhongjin authored
    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: fb257897 ("ASoC: Work around allmodconfig failure")
    Signed-off-by: default avatarChen Zhongjin <chenzhongjin@huawei.com>
    Link: https://lore.kernel.org/r/20221028031603.59416-1-chenzhongjin@huawei.comSigned-off-by: default avatarMark Brown <broonie@kernel.org>
    6ec27c53
soc-core.c 86.2 KB