Hello,

syzbot found 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=15c1a387200000 kernel config: https://syzkaller.appspot.com/x/.config?x=23e37f59d94ddd15 dashboard link: https://syzkaller.appspot.com/bug?extid=8016c844427ade041774 compiler: gcc (GCC) 9.0.0 20181231 (experimental) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=179a01b7200000

IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+8016c844427ade041774@syzkaller.appspotmail.com

usb 2-1: USB disconnect, device number 16 list_add corruption. prev->next should be next (ffff8880a8672358), but was ffff8880a4cde0e8. (prev=ffff8880a4cde868). snd_usb_toneport 4-1:0.0: Line 6 POD Studio UX2 found ------------[ cut here ]------------ usb 6-1: USB disconnect, device number 16 kernel BUG at lib/list_debug.c:26! invalid opcode: 0000 [#1] SMP KASAN PTI CPU: 0 PID: 5 Comm: kworker/0:0 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 RIP: 0010:__list_add_valid.cold+0x3a/0x3c lib/list_debug.c:26 Code: 0b 48 89 f2 4c 89 e1 48 89 ee 48 c7 c7 80 94 b3 8e 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 RSP: 0018:ffff8880a846f110 EFLAGS: 00010286 RAX: 0000000000000075 RBX: ffff8880a8672280 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff815b1e42 RDI: ffffed101508de14 RBP: ffff8880a52679a8 R08: 0000000000000075 R09: ffffed1015a04fc9 R10: ffffed1015a04fc8 R11: ffff8880ad027e47 R12: ffff8880a8672358 R13: ffff8880a4cde868 R14: ffff8880a52679b0 R15: ffff8880a8672358 FS: 0000000000000000(0000) GS:ffff8880ad000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000625208 CR3: 00000000958dc000 CR4: 00000000001406f0 Call Trace: __list_add include/linux/list.h:60 [inline] list_add_tail include/linux/list.h:93 [inline] snd_info_create_entry+0x25f/0x400 sound/core/info.c:717 snd_info_create_module_entry sound/core/info.c:737 [inline] create_subdir+0x27/0xa0 sound/core/info.c:454 snd_info_card_create+0xcf/0x230 sound/core/info.c:528 snd_card_new+0x61d/0x920 sound/core/init.c:255 snd_usb_toneport 3-1:0.0: set_interface failed line6_probe+0x135/0x1150 sound/usb/line6/driver.c:736 snd_usb_toneport 3-1:0.0: Line 6 POD Studio UX2 now disconnected 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 snd_usb_toneport: probe of 3-1:0.0 failed with error -71 __device_attach_driver+0x1d8/0x290 drivers/base/dd.c:778 bus_for_each_drv+0x163/0x1e0 drivers/base/bus.c:454 snd_usb_toneport 4-1:0.0: set_interface failed __device_attach+0x223/0x3a0 drivers/base/dd.c:844 snd_usb_toneport 4-1:0.0: Line 6 POD Studio UX2 now disconnected bus_probe_device+0x1f1/0x2a0 drivers/base/bus.c:514 device_add+0xad2/0x16e0 drivers/base/core.c:2106 snd_usb_toneport: probe of 4-1:0.0 failed with error -71 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 usb 3-1: USB disconnect, device number 16 usb 4-1: USB disconnect, device number 16 __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 2-1: new high-speed USB device number 17 using dummy_hcd 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 usb 6-1: new high-speed USB device number 17 using dummy_hcd 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 152fc83c1caf10d9 ]--- RIP: 0010:__list_add_valid.cold+0x3a/0x3c lib/list_debug.c:26 Code: 0b 48 89 f2 4c 89 e1 48 89 ee 48 c7 c7 80 94 b3 8e 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 RSP: 0018:ffff8880a846f110 EFLAGS: 00010286 RAX: 0000000000000075 RBX: ffff8880a8672280 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff815b1e42 RDI: ffffed101508de14 RBP: ffff8880a52679a8 R08: 0000000000000075 R09: ffffed1015a04fc9 R10: ffffed1015a04fc8 R11: ffff8880ad027e47 R12: ffff8880a8672358 R13: ffff8880a4cde868 R14: ffff8880a52679b0 R15: ffff8880a8672358 FS: 0000000000000000(0000) GS:ffff8880ad000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000625208 CR3: 00000000958dc000 CR4: 00000000001406f0

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