tree 2defe604ef6846d7b74fc2ada20949b0174e55a1
parent bbab59d6c4b2840172af0935a7a6ce2744c42193
author Takashi Iwai <tiwai@suse.de> 1507552335 +0200
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1508312140 +0200

ALSA: line6: Fix missing initialization before error path

commit cb02ffc76a53b5ea751b79b8d4f4d180e5868475 upstream.

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: 790869dacc3d ("ALSA: line6: Add support for POD X3")
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Tested-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>