• Takashi Iwai's avatar
    ALSA: line6: Fix missing initialization before error path · cb02ffc7
    Takashi Iwai authored
    The error path in podhd_init() tries to clear the pending timer, while
    the timer object is initialized at the end of init sequence, thus it
    may hit the uninitialized object, as spotted by syzkaller:
    
      INFO: trying to register non-static key.
      the code is fine but needs lockdep annotation.
      turning off the locking correctness validator.
      CPU: 1 PID: 1845 Comm: kworker/1:2 Not tainted
      4.14.0-rc2-42613-g1488251d1a98 #238
      Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
      Workqueue: usb_hub_wq hub_event
      Call Trace:
       __dump_stack lib/dump_stack.c:16
       dump_stack+0x292/0x395 lib/dump_stack.c:52
       register_lock_class+0x6c4/0x1a00 kernel/locking/lockdep.c:769
       __lock_acquire+0x27e/0x4550 kernel/locking/lockdep.c:3385
       lock_acquire+0x259/0x620 kernel/locking/lockdep.c:4002
       del_timer_sync+0x12c/0x280 kernel/time/timer.c:1237
       podhd_disconnect+0x8c/0x160 sound/usb/line6/podhd.c:299
       line6_probe+0x844/0x1310 sound/usb/line6/driver.c:783
       podhd_probe+0x64/0x70 sound/usb/line6/podhd.c:474
       ....
    
    For addressing it, assure the initializations of timer and work by
    moving them to the beginning of podhd_init().
    
    Fixes: 790869da ("ALSA: line6: Add support for POD X3")
    Reported-by: default avatarAndrey Konovalov <andreyknvl@google.com>
    Tested-by: default avatarAndrey Konovalov <andreyknvl@google.com>
    Cc: <stable@vger.kernel.org>
    Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
    cb02ffc7
podhd.c 12.7 KB