media: usb: siano: Fix warning due to null work_func_t function pointer
[ Upstream commit
6f489a966fbeb0da63d45c2c66a8957eab604bf6 ]
The previous commit
ebad8e731c1c ("media: usb: siano: Fix use after
free bugs caused by do_submit_urb") adds cancel_work_sync() in
smsusb_stop_streaming(). But smsusb_stop_streaming() may be called,
even if the work_struct surb->wq has not been initialized. As a result,
the warning will occur. One of the processes that could lead to warning
is shown below:
smsusb_probe()
smsusb_init_device()
if (!dev->in_ep || !dev->out_ep || align < 0) {
smsusb_term_device(intf);
smsusb_stop_streaming()
cancel_work_sync(&dev->surbs[i].wq);
__cancel_work_timer()
__flush_work()
if (WARN_ON(!work->func)) // work->func is null
The log reported by syzbot is shown below:
WARNING: CPU: 0 PID: 897 at kernel/workqueue.c:3066 __flush_work+0x798/0xa80 kernel/workqueue.c:3063
Modules linked in:
CPU: 0 PID: 897 Comm: kworker/0:2 Not tainted 6.2.0-rc1-syzkaller #0
RIP: 0010:__flush_work+0x798/0xa80 kernel/workqueue.c:3066
...
RSP: 0018:
ffffc9000464ebf8 EFLAGS:
00010246
RAX:
1ffff11002dbb420 RBX:
0000000000000021 RCX:
1ffffffff204fa4e
RDX:
dffffc0000000000 RSI:
0000000000000001 RDI:
ffff888016dda0e8
RBP:
ffffc9000464ed98 R08:
0000000000000001 R09:
ffffffff90253b2f
R10:
0000000000000001 R11:
0000000000000000 R12:
ffff888016dda0e8
R13:
ffff888016dda0e8 R14:
ffff888016dda100 R15:
0000000000000001
FS:
0000000000000000(0000) GS:
ffff8880b9a00000(0000) knlGS:
0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0:
0000000080050033
CR2:
00007ffd4331efe8 CR3:
000000000b48e000 CR4:
00000000003506f0
DR0:
0000000000000000 DR1:
0000000000000000 DR2:
0000000000000000
DR3:
0000000000000000 DR6:
00000000fffe0ff0 DR7:
0000000000000400
Call Trace:
<TASK>
__cancel_work_timer+0x315/0x460 kernel/workqueue.c:3160
smsusb_stop_streaming drivers/media/usb/siano/smsusb.c:182 [inline]
smsusb_term_device+0xda/0x2d0 drivers/media/usb/siano/smsusb.c:344
smsusb_init_device+0x400/0x9ce drivers/media/usb/siano/smsusb.c:419
smsusb_probe+0xbbd/0xc55 drivers/media/usb/siano/smsusb.c:567
...
This patch adds check before cancel_work_sync(). If surb->wq has not
been initialized, the cancel_work_sync() will not be executed.
Reported-by: syzbot+27b0b464864741b18b99@syzkaller.appspotmail.com
Fixes:
ebad8e731c1c ("media: usb: siano: Fix use after free bugs caused by do_submit_urb")
Signed-off-by: Duoming Zhou <duoming@zju.edu.cn>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Sasha Levin <sashal@kernel.org>