general protection fault, probably for non-canonical address 0xdffffc000000000a: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000050-0x0000000000000057]
CPU: 0 PID: 8266 Comm: syz.3.776 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:dummy_queue+0x1a6/0x910 drivers/usb/gadget/udc/dummy_hcd.c:736
Code: fc ff df 80 3c 08 00 74 08 4c 89 e7 e8 b3 9f 23 fb 4d 8b 24 24 49 83 c4 50 4c 89 e0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <0f> b6 04 08 84 c0 0f 85 09 06 00 00 45 8b 24 24 44 89 e6 83 e6 02
RSP: 0018:ffffc90019b17930 EFLAGS: 00010006
RAX: 000000000000000a RBX: ffff88807ea33710 RCX: dffffc0000000000
RDX: ffff88802b9bbc00 RSI: 0000000000000003 RDI: 0000000000000005
RBP: ffff88807ea33700 R08: ffff8880299f639b R09: 1ffff1100533ec73
R10: dffffc0000000000 R11: ffffed100533ec74 R12: 0000000000000050
R13: 1ffff1100fd466e0 R14: ffff8880250900e0 R15: ffff888025090c00
FS:  00007f878ac926c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c35bf00 CR3: 000000002e0a9000 CR4: 00000000003506f0
Call Trace:
 <TASK>
 usb_ep_queue+0xea/0x350 drivers/usb/gadget/udc/core.c:305
 gs_start_tx+0x3fb/0xd40 drivers/usb/gadget/function/u_serial.c:276
 gs_write+0xba/0xe0 drivers/usb/gadget/function/u_serial.c:749
 process_output_block drivers/tty/n_tty.c:580 [inline]
 n_tty_write+0xd3d/0x11e0 drivers/tty/n_tty.c:2395
 iterate_tty_write drivers/tty/tty_io.c:1017 [inline]
 file_tty_write+0x529/0x960 drivers/tty/tty_io.c:1088
 call_write_iter include/linux/fs.h:2018 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x474/0x9a0 fs/read_write.c:584
 ksys_write+0x151/0x260 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f8789d9e0d9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f878ac92028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f878a025fa0 RCX: 00007f8789d9e0d9
RDX: 0000000000000002 RSI: 0000200000000a00 RDI: 0000000000000004
RBP: 00007f8789e35024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f878a026038 R14: 00007f878a025fa0 R15: 00007fffd117a3b8
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:dummy_queue+0x1a6/0x910 drivers/usb/gadget/udc/dummy_hcd.c:736
Code: fc ff df 80 3c 08 00 74 08 4c 89 e7 e8 b3 9f 23 fb 4d 8b 24 24 49 83 c4 50 4c 89 e0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <0f> b6 04 08 84 c0 0f 85 09 06 00 00 45 8b 24 24 44 89 e6 83 e6 02
RSP: 0018:ffffc90019b17930 EFLAGS: 00010006
RAX: 000000000000000a RBX: ffff88807ea33710 RCX: dffffc0000000000
RDX: ffff88802b9bbc00 RSI: 0000000000000003 RDI: 0000000000000005
RBP: ffff88807ea33700 R08: ffff8880299f639b R09: 1ffff1100533ec73
R10: dffffc0000000000 R11: ffffed100533ec74 R12: 0000000000000050
R13: 1ffff1100fd466e0 R14: ffff8880250900e0 R15: ffff888025090c00
FS:  00007f878ac926c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c35bf00 CR3: 000000002e0a9000 CR4: 00000000003506f0
----------------
Code disassembly (best guess):
   0:	fc                   	cld
   1:	ff                   	lcall  (bad)
   2:	df 80 3c 08 00 74    	filds  0x7400083c(%rax)
   8:	08 4c 89 e7          	or     %cl,-0x19(%rcx,%rcx,4)
   c:	e8 b3 9f 23 fb       	call   0xfb239fc4
  11:	4d 8b 24 24          	mov    (%r12),%r12
  15:	49 83 c4 50          	add    $0x50,%r12
  19:	4c 89 e0             	mov    %r12,%rax
  1c:	48 c1 e8 03          	shr    $0x3,%rax
  20:	48 b9 00 00 00 00 00 	movabs $0xdffffc0000000000,%rcx
  27:	fc ff df
* 2a:	0f b6 04 08          	movzbl (%rax,%rcx,1),%eax <-- trapping instruction
  2e:	84 c0                	test   %al,%al
  30:	0f 85 09 06 00 00    	jne    0x63f
  36:	45 8b 24 24          	mov    (%r12),%r12d
  3a:	44 89 e6             	mov    %r12d,%esi
  3d:	83 e6 02             	and    $0x2,%esi