Re: BUG: corrupted list in snd_info_free_entry

[syzbot]

syzbot has found a reproducer for the following crash on:

HEAD commit:    9a33b369 usb-fuzzer: main usb gadget fuzzer driver
git tree:       https://github.com/google/kasan/tree/usb-fuzzer
console output: https://syzkaller.appspot.com/x/log.txt?x=111b89d3200000
kernel config:  https://syzkaller.appspot.com/x/.config?x=23e37f59d94ddd15
dashboard link: https://syzkaller.appspot.com/bug?extid=90cf07b4a2473213d16b
compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1611baf3200000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1665618f200000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+90cf07b4a2473213d16b@xxxxxxxxxxxxxxxxxxxxxxxxx

snd_usb_toneport 5-1:0.0: set_interface failed
list_del corruption. prev->next should be ffff8880a78a4868, but was  
ffff88821b198ea8
snd_usb_toneport 4-1:0.0: Line 6 POD Studio UX2 now disconnected
------------[ cut here ]------------
snd_usb_toneport 5-1:0.0: Line 6 POD Studio UX2 now disconnected
kernel BUG at lib/list_debug.c:51!
invalid opcode: 0000 [#1] SMP KASAN PTI
snd_usb_toneport: probe of 5-1:0.0 failed with error -71
CPU: 1 PID: 537 Comm: kworker/1:3 Not tainted 5.1.0-rc4-319354-g9a33b36 #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
Workqueue: usb_hub_wq hub_event
snd_usb_toneport: probe of 4-1:0.0 failed with error -71
RIP: 0010:__list_del_entry_valid.cold+0xf/0x55 lib/list_debug.c:51
Code: e8 69 e7 e9 fd 0f 0b 48 89 f1 48 c7 c7 00 94 b3 8e 4c 89 e6 e8 55 e7  
e9 fd 0f 0b 48 89 ee 48 c7 c7 a0 95 b3 8e e8 44 e7 e9 fd <0f> 0b 4c 89 ea  
48 89 ee 48 c7 c7 e0 94 b3 8e e8 30 e7 e9 fd 0f 0b
RSP: 0018:ffff88809eddf118 EFLAGS: 00010282
RAX: 0000000000000054 RBX: ffff8880a78a4770 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff815b1e42 RDI: ffffed1013dbbe15
RBP: ffff8880a78a4868 R08: 0000000000000054 R09: ffffed1015a24fc9
R10: ffffed1015a24fc8 R11: ffff8880ad127e47 R12: ffff88809cafbea8
usb 5-1: USB disconnect, device number 41
R13: ffff8880a74abc18 R14: ffff8880a78a4770 R15: ffff8880a78a4858
FS:  0000000000000000(0000) GS:ffff8880ad100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4fcd865000 CR3: 00000000945aa000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
usb 4-1: USB disconnect, device number 41
Call Trace:
 __list_del_entry include/linux/list.h:117 [inline]
 list_del include/linux/list.h:125 [inline]
 snd_info_free_entry+0x137/0x340 sound/core/info.c:795
 snd_info_card_free+0x43/0x90 sound/core/info.c:606
 snd_card_do_free sound/core/init.c:469 [inline]
 release_card_device+0x8b/0x100 sound/core/init.c:156
 device_release+0x7d/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+0x1df/0x4f0 lib/kobject.c:708
 put_device+0x21/0x30 drivers/base/core.c:2205
 snd_card_free_when_closed+0x3a/0x50 sound/core/init.c:493
 line6_disconnect.cold+0xa3/0xbc sound/usb/line6/driver.c:833
 line6_probe+0xb23/0x1150 sound/usb/line6/driver.c:799
 usb_probe_interface+0x31d/0x820 drivers/usb/core/driver.c:361
 really_probe+0x2da/0xb10 drivers/base/dd.c:509
 driver_probe_device+0x21d/0x350 drivers/base/dd.c:671
 __device_attach_driver+0x1d8/0x290 drivers/base/dd.c:778
 bus_for_each_drv+0x163/0x1e0 drivers/base/bus.c:454
 __device_attach+0x223/0x3a0 drivers/base/dd.c:844
 bus_probe_device+0x1f1/0x2a0 drivers/base/bus.c:514
 device_add+0xad2/0x16e0 drivers/base/core.c:2106
 usb_set_configuration+0xdf7/0x1740 drivers/usb/core/message.c:2021
 generic_probe+0xa2/0xda drivers/usb/core/generic.c:210
 usb_probe_device+0xc0/0x150 drivers/usb/core/driver.c:266
 really_probe+0x2da/0xb10 drivers/base/dd.c:509
 driver_probe_device+0x21d/0x350 drivers/base/dd.c:671
 __device_attach_driver+0x1d8/0x290 drivers/base/dd.c:778
 bus_for_each_drv+0x163/0x1e0 drivers/base/bus.c:454
 __device_attach+0x223/0x3a0 drivers/base/dd.c:844
 bus_probe_device+0x1f1/0x2a0 drivers/base/bus.c:514
 device_add+0xad2/0x16e0 drivers/base/core.c:2106
 usb_new_device.cold+0x537/0xccf 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+0x138e/0x3b00 drivers/usb/core/hub.c:5432
 process_one_work+0x90f/0x1580 kernel/workqueue.c:2269
 process_scheduled_works kernel/workqueue.c:2331 [inline]
 worker_thread+0x7b0/0xe20 kernel/workqueue.c:2417
 kthread+0x313/0x420 kernel/kthread.c:253
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
Modules linked in:
---[ end trace f69ca8f71496c60d ]---
RIP: 0010:__list_del_entry_valid.cold+0xf/0x55 lib/list_debug.c:51
snd_usb_toneport 1-1:0.0: set_interface failed
Code: e8 69 e7 e9 fd 0f 0b 48 89 f1 48 c7 c7 00 94 b3 8e 4c 89 e6 e8 55 e7  
e9 fd 0f 0b 48 89 ee 48 c7 c7 a0 95 b3 8e e8 44 e7 e9 fd <0f> 0b 4c 89 ea  
48 89 ee 48 c7 c7 e0 94 b3 8e e8 30 e7 e9 fd 0f 0b
RSP: 0018:ffff88809eddf118 EFLAGS: 00010282
snd_usb_toneport 1-1:0.0: Line 6 POD Studio UX2 now disconnected
RAX: 0000000000000054 RBX: ffff8880a78a4770 RCX: 0000000000000000
snd_usb_toneport: probe of 1-1:0.0 failed with error -71
RDX: 0000000000000000 RSI: ffffffff815b1e42 RDI: ffffed1013dbbe15
RBP: ffff8880a78a4868 R08: 0000000000000054 R09: ffffed1015a24fc9
R10: ffffed1015a24fc8 R11: ffff8880ad127e47 R12: ffff88809cafbea8
R13: ffff8880a74abc18 R14: ffff8880a78a4770 R15: ffff8880a78a4858
FS:  0000000000000000(0000) GS:ffff8880ad100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
usb 1-1: USB disconnect, device number 42
CR2: 00007f4fcd865000 CR3: 000000001167a000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400