syzbot
general protection fault in bus_remove_device
Status:
upstream: reported C repro on 2026/08/11 17:31
Reported-by: syzbot+c0ac61184bc58a7ca6e5@syzkaller.appspotmail.com
First crash: 12d, last: 4d10h
Sample crash report:
usb 1-1: 1:1 : UAC_AS_GENERAL descriptor not found
usb 1-1: selecting invalid altsetting 0
usb 1-1: USB disconnect, device number 2
general protection fault, probably for non-canonical address 0xdffffc0000000004: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027]
CPU: 0 PID: 15 Comm: kworker/0:1 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: usb_hub_wq hub_event
RIP: 0010:klist_put lib/klist.c:212 [inline]
RIP: 0010:klist_del lib/klist.c:230 [inline]
RIP: 0010:klist_remove+0x150/0x300 lib/klist.c:249
Code: 28 02 49 89 df 49 c1 ef 03 43 80 3c 27 00 74 08 48 89 df e8 d2 68 45 ff 4c 8b 33 49 83 e6 fe 49 8d 7e 20 48 89 f8 48 c1 e8 03 <42> 80 3c 20 00 74 05 e8 b4 68 45 ff 49 8b 46 20 48 89 44 24 18 4c
RSP: 0018:ffffc900000f76a0 EFLAGS: 00010202
RAX: 0000000000000004 RBX: ffff88810b2a8048 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8676f940 RDI: 0000000000000020
RBP: ffffc900000f7798 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff5200001eec4 R12: dffffc0000000000
R13: 1ffff9200001eed8 R14: 0000000000000000 R15: 1ffff11021655009
FS: 0000000000000000(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000056345d7f4a00 CR3: 000000010dc35000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__device_release_driver drivers/base/dd.c:1203 [inline]
device_release_driver_internal+0x67e/0x7c0 drivers/base/dd.c:1221
device_release_driver+0x19/0x20 drivers/base/dd.c:1244
bus_remove_device+0x2df/0x340 drivers/base/bus.c:535
device_del+0x62e/0xe60 drivers/base/core.c:3453
usb_disable_device+0x3a8/0x750 drivers/usb/core/message.c:1470
usb_disconnect+0x32d/0x870 drivers/usb/core/hub.c:2310
hub_port_connect drivers/usb/core/hub.c:5338 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5639 [inline]
port_event drivers/usb/core/hub.c:5805 [inline]
hub_event+0x19c2/0x4220 drivers/usb/core/hub.c:5887
process_one_work+0x6fd/0xbc0 kernel/workqueue.c:2301
process_scheduled_works kernel/workqueue.c:2363 [inline]
worker_thread+0xd1c/0x13c0 kernel/workqueue.c:2449
kthread+0x324/0x3b0 kernel/kthread.c:313
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
Modules linked in:
---[ end trace 9295c950aa600471 ]---
RIP: 0010:klist_put lib/klist.c:212 [inline]
RIP: 0010:klist_del lib/klist.c:230 [inline]
RIP: 0010:klist_remove+0x150/0x300 lib/klist.c:249
Code: 28 02 49 89 df 49 c1 ef 03 43 80 3c 27 00 74 08 48 89 df e8 d2 68 45 ff 4c 8b 33 49 83 e6 fe 49 8d 7e 20 48 89 f8 48 c1 e8 03 <42> 80 3c 20 00 74 05 e8 b4 68 45 ff 49 8b 46 20 48 89 44 24 18 4c
RSP: 0018:ffffc900000f76a0 EFLAGS: 00010202
RAX: 0000000000000004 RBX: ffff88810b2a8048 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8676f940 RDI: 0000000000000020
RBP: ffffc900000f7798 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff5200001eec4 R12: dffffc0000000000
R13: 1ffff9200001eed8 R14: 0000000000000000 R15: 1ffff11021655009
FS: 0000000000000000(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffe0e8b7598 CR3: 00000001009af000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 28 02 sub %al,(%rdx)
2: 49 89 df mov %rbx,%r15
5: 49 c1 ef 03 shr $0x3,%r15
9: 43 80 3c 27 00 cmpb $0x0,(%r15,%r12,1)
e: 74 08 je 0x18
10: 48 89 df mov %rbx,%rdi
13: e8 d2 68 45 ff call 0xff4568ea
18: 4c 8b 33 mov (%rbx),%r14
1b: 49 83 e6 fe and $0xfffffffffffffffe,%r14
1f: 49 8d 7e 20 lea 0x20(%r14),%rdi
23: 48 89 f8 mov %rdi,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 42 80 3c 20 00 cmpb $0x0,(%rax,%r12,1) <-- trapping instruction
2f: 74 05 je 0x36
31: e8 b4 68 45 ff call 0xff4568ea
36: 49 8b 46 20 mov 0x20(%r14),%rax
3a: 48 89 44 24 18 mov %rax,0x18(%rsp)
3f: 4c rex.WR
* Struck through repros no longer work on HEAD.