4.13-stable review patch. If anyone has any objections, please let me know.
------------------
From: Takashi Iwai <tiwai@xxxxxxx>
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@xxxxxxxxxx>
Tested-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
sound/usb/line6/podhd.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
--- a/sound/usb/line6/podhd.c
+++ b/sound/usb/line6/podhd.c
@@ -318,6 +318,9 @@ static int podhd_init(struct usb_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) {
/* claim the data interface */
intf = usb_ifnum_to_if(line6->usbdev,
@@ -359,8 +362,6 @@ static int podhd_init(struct usb_line6 *
}
/* init device and delay registering */
- init_timer(&pod->startup_timer);
- INIT_WORK(&pod->startup_work, podhd_startup_workqueue);
podhd_startup(pod);
return 0;
}