回复: WARNING in submit_audio_out_urb/usb_submit_urb

[Takashi Iwai]

On Fri, 10 Jul 2020 10:12:43 +0200,
Zhang, Qiang wrote:
> 
> 
> 
> ________________________________________
> 发件人: linux-kernel-owner at vger.kernel.org <linux-kernel-owner at vger.kernel.org> 代表 syzbot <syzbot+c190f6858a04ea7fbc52 at syzkaller.appspotmail.com>
> 发送时间: 2020年7月9日 21:34
> 收件人: andreyknvl at google.com; gregkh at linuxfoundation.org; ingrassia at epigenesys.com; linux-kernel at vger.kernel.org; linux-usb at vger.kernel.org; syzkaller-bugs at googlegroups.com
> 主题: WARNING in submit_audio_out_urb/usb_submit_urb
> 
> Hello,
> 
> syzbot found the following crash on:
> 
> HEAD commit:    768a0741 usb: dwc2: gadget: Remove assigned but never used..
> git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
> console output: https://syzkaller.appspot.com/x/log.txt?x=1568d11f100000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=999be4eb2478ffa5
> dashboard link: https://syzkaller.appspot.com/bug?extid=c190f6858a04ea7fbc52
> compiler:       gcc (GCC) 10.1.0-syz 20200507
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=123aa2fb100000
> 
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+c190f6858a04ea7fbc52 at syzkaller.appspotmail.com
> 
> usb 1-1: send failed (error -32)
> snd_usb_toneport 1-1:0.0: Line 6 TonePort GX now attached
> ------------[ cut here ]------------
> usb 1-1: BOGUS urb xfer, pipe 0 != type 3
> WARNING: CPU: 0 PID: 12 at drivers/usb/core/urb.c:478 usb_submit_urb+0xa17/0x13e0 drivers/usb/core/urb.c:478
> Kernel panic - not syncing: panic_on_warn set ...
> CPU: 0 PID: 12 Comm: kworker/0:1 Not tainted 5.8.0-rc3-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> Workqueue: events line6_startup_work
> Call Trace:
>  __dump_stack lib/dump_stack.c:77 [inline]
>  dump_stack+0xf6/0x16e lib/dump_stack.c:118
>  panic+0x2aa/0x6e1 kernel/panic.c:231
>  __warn.cold+0x20/0x50 kernel/panic.c:600
>  report_bug+0x1bd/0x210 lib/bug.c:198
>  handle_bug+0x41/0x80 arch/x86/kernel/traps.c:235
>  exc_invalid_op+0x13/0x40 arch/x86/kernel/traps.c:255
>  asm_exc_invalid_op+0x12/0x20 arch/x86/include/asm/idtentry.h:563
> RIP: 0010:usb_submit_urb+0xa17/0x13e0 drivers/usb/core/urb.c:478
> Code: 84 e7 04 00 00 e8 a9 10 ca fd 4c 89 ef e8 41 79 12 ff 41 89 d8 44 89 e1 4c 89 f2 48 89 c6 48 c7 c7 80 a0 5d 86 e8 db 77 9e fd <0f> 0b e8 82 10 ca fd 0f b6 6c 24 08 48 c7 c6 e0 a1 5d 86 48 89 ef
> RSP: 0018:ffff8881da227b10 EFLAGS: 00010086
> RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000000
> RDX: ffff8881da211900 RSI: ffffffff8129b4e3 RDI: ffffed103b444f54
> RBP: 0000000000000030 R08: 0000000000000001 R09: ffff8881db21fe8b
> R10: 0000000000000000 R11: 0000000000000004 R12: 0000000000000000
> R13: ffff8881d6ecd0a0 R14: ffff8881d3d8c690 R15: ffff8881d54c4000
>  submit_audio_out_urb+0x6d6/0x1a00 sound/usb/line6/playback.c:271
>  line6_submit_audio_out_all_urbs+0xc9/0x120 sound/usb/line6/playback.c:291
>  line6_stream_start+0x187/0x230 sound/usb/line6/pcm.c:195
>  line6_pcm_acquire+0x137/0x210 sound/usb/line6/pcm.c:318
>  line6_startup_work+0x42/0x50 sound/usb/line6/driver.c:734
>  process_one_work+0x94c/0x15f0 kernel/workqueue.c:2269
>  worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
>  kthread+0x392/0x470 kernel/kthread.c:291
>  ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293
> 
>  It's like Alan Stern's reply to the email titled "KASAN: use-after-free Read in line6_submit_audio_in_all_urbs."   It's also like a problem with asynchronous operations. can replace "cancel_delayed_work" with" cancel_delayed_work_sync"
> in "line6_disconnect" func？

No, this looks a different problem.  It's just a matter of the missing
URB type check that leads to a USB warning.  A typical issue with the
USB fuzzing.

I'll check it later.


thanks,

Takashi