Re: WARNING in uvc_scan_chain_forward

[Andrey Konovalov]

On Mon, Dec 16, 2019 at 2:15 PM syzbot
<syzbot+0a5c96772a9b26f2a876@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
>
> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit:    4cc037ec usb: gadget: add raw-gadget interface
> git tree:       https://github.com/google/kasan.git usb-fuzzer
> console output: https://syzkaller.appspot.com/x/log.txt?x=11b905dee00000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=e9c2b6de462bc469
> dashboard link: https://syzkaller.appspot.com/bug?extid=0a5c96772a9b26f2a876
> compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=10f82546e00000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1638ef7ee00000
>
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+0a5c96772a9b26f2a876@xxxxxxxxxxxxxxxxxxxxxxxxx
>
> usb 1-1: New USB device found, idVendor=0bd3, idProduct=0755,
> bcdDevice=69.6a
> usb 1-1: New USB device strings: Mfr=0, Product=0, SerialNumber=0
> usb 1-1: config 0 descriptor??
> usb 1-1: string descriptor 0 read error: -71
> uvcvideo: Found UVC 0.00 device <unnamed> (0bd3:0755)
> ------------[ cut here ]------------
> list_add double add: new=ffff8881d0637010, prev=ffff8881d0637010,
> next=ffff8881d4e87c18.
> WARNING: CPU: 1 PID: 22 at lib/list_debug.c:29 __list_add_valid+0xb4/0xf0
> lib/list_debug.c:29
> Kernel panic - not syncing: panic_on_warn set ...
> CPU: 1 PID: 22 Comm: kworker/1:1 Not tainted 5.5.0-rc1-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
> Google 01/01/2011
> Workqueue: usb_hub_wq hub_event
> Call Trace:
>   __dump_stack lib/dump_stack.c:77 [inline]
>   dump_stack+0xef/0x16e lib/dump_stack.c:118
>   panic+0x2aa/0x6e1 kernel/panic.c:221
>   __warn.cold+0x2f/0x30 kernel/panic.c:582
>   report_bug+0x27b/0x2f0 lib/bug.c:195
>   fixup_bug arch/x86/kernel/traps.c:174 [inline]
>   fixup_bug arch/x86/kernel/traps.c:169 [inline]
>   do_error_trap+0x12b/0x1e0 arch/x86/kernel/traps.c:267
>   do_invalid_op+0x32/0x40 arch/x86/kernel/traps.c:286
>   invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027
> RIP: 0010:__list_add_valid+0xb4/0xf0 lib/list_debug.c:29
> Code: 48 c7 c7 e0 f3 da 85 4c 89 e6 e8 ef cf 2b ff 0f 0b 31 c0 eb c5 48 89
> f2 4c 89 e1 48 89 ee 48 c7 c7 60 f4 da 85 e8 d4 cf 2b ff <0f> 0b 31 c0 eb
> aa 48 89 34 24 e8 fd 3c 7f ff 48 8b 34 24 e9 60 ff
> RSP: 0018:ffff8881d8c37080 EFLAGS: 00010286
> RAX: 0000000000000000 RBX: ffff8881d0637010 RCX: 0000000000000000
> RDX: 0000000000000000 RSI: ffffffff81295dad RDI: ffffed103b186e02
> RBP: ffff8881d0637010 R08: ffff8881da24e200 R09: fffffbfff11f1eae
> R10: fffffbfff11f1ead R11: ffffffff88f8f56f R12: ffff8881d4e87c18
> R13: ffff8881d0637000 R14: dffffc0000000000 R15: ffff8881d4e87c18
>   __list_add include/linux/list.h:60 [inline]
>   list_add_tail include/linux/list.h:93 [inline]
>   uvc_scan_chain_forward.isra.0+0x4df/0x637
> drivers/media/usb/uvc/uvc_driver.c:1526
>   uvc_scan_chain drivers/media/usb/uvc/uvc_driver.c:1640 [inline]
>   uvc_scan_device drivers/media/usb/uvc/uvc_driver.c:1824 [inline]
>   uvc_probe.cold+0x1aee/0x29de drivers/media/usb/uvc/uvc_driver.c:2197
>   usb_probe_interface+0x305/0x7a0 drivers/usb/core/driver.c:361
>   really_probe+0x281/0x6d0 drivers/base/dd.c:548
>   driver_probe_device+0x104/0x210 drivers/base/dd.c:721
>   __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:828
>   bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:430
>   __device_attach+0x217/0x360 drivers/base/dd.c:894
>   bus_probe_device+0x1e4/0x290 drivers/base/bus.c:490
>   device_add+0x1480/0x1c20 drivers/base/core.c:2487
>   usb_set_configuration+0xe67/0x1740 drivers/usb/core/message.c:2023
>   generic_probe+0x9d/0xd5 drivers/usb/core/generic.c:210
>   usb_probe_device+0x99/0x100 drivers/usb/core/driver.c:266
>   really_probe+0x281/0x6d0 drivers/base/dd.c:548
>   driver_probe_device+0x104/0x210 drivers/base/dd.c:721
>   __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:828
>   bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:430
>   __device_attach+0x217/0x360 drivers/base/dd.c:894
>   bus_probe_device+0x1e4/0x290 drivers/base/bus.c:490
>   device_add+0x1480/0x1c20 drivers/base/core.c:2487
>   usb_new_device.cold+0x6a4/0xe79 drivers/usb/core/hub.c:2537
>   hub_port_connect drivers/usb/core/hub.c:5184 [inline]
>   hub_port_connect_change drivers/usb/core/hub.c:5324 [inline]
>   port_event drivers/usb/core/hub.c:5470 [inline]
>   hub_event+0x1e59/0x3860 drivers/usb/core/hub.c:5552
>   process_one_work+0x92b/0x1530 kernel/workqueue.c:2264
>   worker_thread+0x96/0xe20 kernel/workqueue.c:2410
>   kthread+0x318/0x420 kernel/kthread.c:255
>   ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
> Kernel Offset: disabled
> Rebooting in 86400 seconds..
>
>
> ---
> This bug is generated by a bot. It may contain errors.
> See https://goo.gl/tpsmEJ for more information about syzbot.
> syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxxx
>
> syzbot will keep track of this bug report. See:
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> syzbot can test patches for this bug, for details see:
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#syz fix: media: uvc: Avoid cyclic entity chains due to malformed USB
descriptors