cdc_acm 5-1:1.0: ttyACM0: USB ACM device
usb 5-1: USB disconnect, device number 3
general protection fault, probably for non-canonical address 0xdffffc0000000004: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027]
CPU: 1 PID: 287 Comm: kworker/1:2 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 12 6c 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 f4 6b 45 ff 49 8b 46 20 48 89 44 24 18 4c
RSP: 0018:ffffc90000c874c0 EFLAGS: 00010202
RAX: 0000000000000004 RBX: ffff8881118c5848 RCX: 0000000000000000
RDX: ffffc90008bfd000 RSI: 0000000000002e1f RDI: 0000000000000020
RBP: ffffc90000c875a8 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000190e88 R12: dffffc0000000000
R13: 1ffff92000190e9c R14: 0000000000000000 R15: 1ffff11022318b09
FS:  0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6fd5a44060 CR3: 000000010dcf8000 CR4: 00000000003506a0
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
 usb_driver_release_interface+0x140/0x1b0 drivers/usb/core/driver.c:632
 acm_disconnect+0xa5a/0xb20 drivers/usb/class/cdc-acm.c:1628
 usb_unbind_interface+0x212/0x8a0 drivers/usb/core/driver.c:459
 __device_release_driver drivers/base/dd.c:-1 [inline]
 device_release_driver_internal+0x531/0x7c0 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 261d8398b02d6b81 ]---
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 12 6c 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 f4 6b 45 ff 49 8b 46 20 48 89 44 24 18 4c
RSP: 0018:ffffc90000c874c0 EFLAGS: 00010202
RAX: 0000000000000004 RBX: ffff8881118c5848 RCX: 0000000000000000
RDX: ffffc90008bfd000 RSI: 0000000000002e1f RDI: 0000000000000020
RBP: ffffc90000c875a8 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000190e88 R12: dffffc0000000000
R13: 1ffff92000190e9c R14: 0000000000000000 R15: 1ffff11022318b09
FS:  0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6fd5a44060 CR3: 000000012b397000 CR4: 00000000003506a0
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 12 6c 45 ff       	call   0xff456c2a
  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 f4 6b 45 ff       	call   0xff456c2a
  36:	49 8b 46 20          	mov    0x20(%r14),%rax
  3a:	48 89 44 24 18       	mov    %rax,0x18(%rsp)
  3f:	4c                   	rex.WR