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ALSA: line6: Fix missing initialization before error path

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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: 790869dacc ("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>
This commit is contained in:
Takashi Iwai
2017-10-09 14:32:15 +02:00
committed by Greg Kroah-Hartman
parent bbab59d6c4
commit b65f99b8b1
1 changed files with 3 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files
sound/usb/line6/podhd.c
+3 -2
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@@ -307,6 +307,9 @@ static int podhd_init(struct usb_line6 *line6,
line6->disconnect = podhd_disconnect;
init_timer(&pod->startup_timer);
INIT_WORK(&pod->startup_work, podhd_startup_workqueue);
if (pod->line6.properties->capabilities & LINE6_CAP_CONTROL) {
/* create sysfs entries: */
err = snd_card_add_dev_attr(line6->card, &podhd_dev_attr_group);
@@ -330,8 +333,6 @@ static int podhd_init(struct usb_line6 *line6,
}
/* init device and delay registering */
init_timer(&pod->startup_timer);
INIT_WORK(&pod->startup_work, podhd_startup_workqueue);
podhd_startup(pod);
return 0;
}