Re: WARNING in snd_info_free_entry

[Andrey Konovalov]

From: syzbot <syzbot+131dee8780c719bc6afb@xxxxxxxxxxxxxxxxxxxxxxxxx>
Date: Wed, May 15, 2019 at 2:37 PM
To: <alsa-devel@xxxxxxxxxxxxxxxx>, <andreyknvl@xxxxxxxxxx>,
<joe@xxxxxxxxxxx>, <linux-kernel@xxxxxxxxxxxxxxx>,
<linux-usb@xxxxxxxxxxxxxxx>, <perex@xxxxxxxx>,
<syzkaller-bugs@xxxxxxxxxxxxxxxx>, <tiwai@xxxxxxxx>,
<vkoul@xxxxxxxxxx>

> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit:    43151d6c usb-fuzzer: main usb gadget fuzzer driver
> git tree:       https://github.com/google/kasan.git usb-fuzzer
> console output: https://syzkaller.appspot.com/x/log.txt?x=16ae9974a00000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=95aff7278e7ff25e
> dashboard link: https://syzkaller.appspot.com/bug?extid=131dee8780c719bc6afb
> compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=173f3574a00000
>
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+131dee8780c719bc6afb@xxxxxxxxxxxxxxxxxxxxxxxxx
>
> snd_usb_toneport 6-1:0.0: set_interface failed
> snd_usb_toneport 6-1:0.0: Line 6 POD Studio UX2 now disconnected
> ------------[ cut here ]------------
> list_del corruption. prev->next should be ffff8881d13fa728, but was
> ffff8881d82ebd68
> WARNING: CPU: 1 PID: 1477 at lib/list_debug.c:51
> __list_del_entry_valid+0x101/0x170 lib/list_debug.c:51
> Kernel panic - not syncing: panic_on_warn set ...
> CPU: 1 PID: 1477 Comm: kworker/1:2 Not tainted 5.1.0-rc3+ #8
> 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+0xca/0x13e lib/dump_stack.c:113
>   panic+0x292/0x5e1 kernel/panic.c:214
>   __warn.cold+0x20/0x53 kernel/panic.c:571
>   report_bug+0x262/0x2a0 lib/bug.c:186
>   fixup_bug arch/x86/kernel/traps.c:179 [inline]
>   fixup_bug arch/x86/kernel/traps.c:174 [inline]
>   do_error_trap+0x12b/0x1e0 arch/x86/kernel/traps.c:272
>   do_invalid_op+0x32/0x40 arch/x86/kernel/traps.c:291
>   invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:973
> RIP: 0010:__list_del_entry_valid+0x101/0x170 lib/list_debug.c:51
> Code: c4 08 31 c0 41 5c 41 5d c3 4c 89 e2 48 c7 c7 20 f7 d8 85 e8 1c 2a 35
> ff 0f 0b 31 c0 eb c6 48 c7 c7 80 f7 d8 85 e8 0a 2a 35 ff <0f> 0b 31 c0 eb
> b4 48 c7 c7 e0 f7 d8 85 e8 f8 29 35 ff 0f 0b 31 c0
> RSP: 0018:ffff8881d7a1f078 EFLAGS: 00010282
> RAX: 0000000000000000 RBX: ffff8881d13fa630 RCX: 0000000000000000
> RDX: 0000000000000000 RSI: ffffffff8127bbcd RDI: ffffed103af43e01
> RBP: ffff8881d13fa640 R08: ffff8881d7a10000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000000 R12: ffff8881d13fad68
> R13: ffff8881d7f1d858 R14: ffff8881d13fa630 R15: ffff8881d13fa718
>   __list_del_entry include/linux/list.h:117 [inline]
>   list_del include/linux/list.h:125 [inline]
>   snd_info_free_entry+0x132/0x340 sound/core/info.c:795
>   snd_info_card_free+0x3e/0x80 sound/core/info.c:606
>   snd_card_do_free sound/core/init.c:469 [inline]
>   release_card_device+0x63/0xd0 sound/core/init.c:156
>   device_release+0x78/0x210 drivers/base/core.c:1064
>   kobject_cleanup lib/kobject.c:662 [inline]
>   kobject_release lib/kobject.c:691 [inline]
>   kref_put include/linux/kref.h:67 [inline]
>   kobject_put+0x17d/0x270 lib/kobject.c:708
>   put_device+0x1c/0x30 drivers/base/core.c:2205
>   snd_card_free_when_closed+0x35/0x50 sound/core/init.c:493
>   line6_disconnect.cold+0xa3/0xbc sound/usb/line6/driver.c:833
>   line6_probe+0xb1e/0x1140 sound/usb/line6/driver.c:799
>   usb_probe_interface+0x30d/0x7b0 drivers/usb/core/driver.c:361
>   really_probe+0x296/0x680 drivers/base/dd.c:509
>   driver_probe_device+0xf9/0x200 drivers/base/dd.c:671
>   __device_attach_driver+0x1c4/0x230 drivers/base/dd.c:778
>   bus_for_each_drv+0x15e/0x1e0 drivers/base/bus.c:454
>   __device_attach+0x21e/0x360 drivers/base/dd.c:844
>   bus_probe_device+0x1ec/0x2a0 drivers/base/bus.c:514
>   device_add+0xaf4/0x1700 drivers/base/core.c:2106
>   usb_set_configuration+0xdf2/0x1670 drivers/usb/core/message.c:2023
>   generic_probe+0x9d/0xd5 drivers/usb/core/generic.c:210
>   usb_probe_device+0xa8/0x110 drivers/usb/core/driver.c:266
>   really_probe+0x296/0x680 drivers/base/dd.c:509
>   driver_probe_device+0xf9/0x200 drivers/base/dd.c:671
>   __device_attach_driver+0x1c4/0x230 drivers/base/dd.c:778
>   bus_for_each_drv+0x15e/0x1e0 drivers/base/bus.c:454
>   __device_attach+0x21e/0x360 drivers/base/dd.c:844
>   bus_probe_device+0x1ec/0x2a0 drivers/base/bus.c:514
>   device_add+0xaf4/0x1700 drivers/base/core.c:2106
>   usb_new_device.cold+0x8b8/0x1030 drivers/usb/core/hub.c:2534
>   hub_port_connect drivers/usb/core/hub.c:5089 [inline]
>   hub_port_connect_change drivers/usb/core/hub.c:5204 [inline]
>   port_event drivers/usb/core/hub.c:5350 [inline]
>   hub_event+0x1ac9/0x35a0 drivers/usb/core/hub.c:5432
>   process_one_work+0x90a/0x1580 kernel/workqueue.c:2269
>   process_scheduled_works kernel/workqueue.c:2331 [inline]
>   worker_thread+0x7ab/0xe20 kernel/workqueue.c:2417
>   kthread+0x30e/0x420 kernel/kthread.c:253
>   ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
> Kernel Offset: disabled
> Rebooting in 86400 seconds..

#syz dup: KASAN: use-after-free Read in snd_info_free_entry

>
>
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