Oops: general protection fault, probably for non-canonical address 0xdffffc000000001f: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x00000000000000f8-0x00000000000000ff]
CPU: 0 PID: 8 Comm: kworker/0:0 Not tainted 6.9.0-rc2-next-20240403-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Workqueue: pm pm_runtime_work
RIP: 0010:serial8250_tx_chars+0x28c/0x8a0 drivers/tty/serial/8250/8250_port.c:1799
Code: 5a ff bf fc 48 8b 2b 48 8b 44 24 20 42 0f b6 04 38 84 c0 0f 85 97 02 00 00 48 8b 04 24 48 63 00 48 01 c5 48 89 e8 48 c1 e8 03 <42> 0f b6 04 38 84 c0 0f 85 99 02 00 00 0f b6 6d 00 48 8b 44 24 58
RSP: 0018:ffffc900000d7830 EFLAGS: 00010002
RAX: 000000000000001f RBX: ffff8880201d0fd0 RCX: 1ffffffff294c06f
RDX: 1ffffffff294c0b9 RSI: 00000000000000fb RDI: ffffffff94a605d0
RBP: 00000000000000fb R08: ffffffff853a5357 R09: fffff5200001af00
R10: dffffc0000000000 R11: ffffffff853b02a0 R12: ffffffff94a60370
R13: ffffffff94a60428 R14: ffffffff94a60320 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f25a137abf8 CR3: 0000000064b7a000 CR4: 00000000003506f0
Call Trace:
 <TASK>
 __start_tx+0x32e/0x470 drivers/tty/serial/8250/8250_port.c:1534
 serial_port_runtime_suspend+0x21d/0x2e0 drivers/tty/serial/serial_port.c:65
 __rpm_callback+0x2df/0x790 drivers/base/power/runtime.c:394
 rpm_callback drivers/base/power/runtime.c:448 [inline]
 rpm_suspend+0x88c/0x1730 drivers/base/power/runtime.c:672
 pm_runtime_work+0x175/0x210 drivers/base/power/runtime.c:976
 process_one_work kernel/workqueue.c:3218 [inline]
 process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3299
 worker_thread+0x86d/0xd70 kernel/workqueue.c:3380
 kthread+0x2f0/0x390 kernel/kthread.c:388
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:serial8250_tx_chars+0x28c/0x8a0 drivers/tty/serial/8250/8250_port.c:1799
Code: 5a ff bf fc 48 8b 2b 48 8b 44 24 20 42 0f b6 04 38 84 c0 0f 85 97 02 00 00 48 8b 04 24 48 63 00 48 01 c5 48 89 e8 48 c1 e8 03 <42> 0f b6 04 38 84 c0 0f 85 99 02 00 00 0f b6 6d 00 48 8b 44 24 58
RSP: 0018:ffffc900000d7830 EFLAGS: 00010002
RAX: 000000000000001f RBX: ffff8880201d0fd0 RCX: 1ffffffff294c06f
RDX: 1ffffffff294c0b9 RSI: 00000000000000fb RDI: ffffffff94a605d0
RBP: 00000000000000fb R08: ffffffff853a5357 R09: fffff5200001af00
R10: dffffc0000000000 R11: ffffffff853b02a0 R12: ffffffff94a60370
R13: ffffffff94a60428 R14: ffffffff94a60320 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f25a137abf8 CR3: 0000000064b7a000 CR4: 00000000003506f0
----------------
Code disassembly (best guess), 2 bytes skipped:
   0:	bf fc 48 8b 2b       	mov    $0x2b8b48fc,%edi
   5:	48 8b 44 24 20       	mov    0x20(%rsp),%rax
   a:	42 0f b6 04 38       	movzbl (%rax,%r15,1),%eax
   f:	84 c0                	test   %al,%al
  11:	0f 85 97 02 00 00    	jne    0x2ae
  17:	48 8b 04 24          	mov    (%rsp),%rax
  1b:	48 63 00             	movslq (%rax),%rax
  1e:	48 01 c5             	add    %rax,%rbp
  21:	48 89 e8             	mov    %rbp,%rax
  24:	48 c1 e8 03          	shr    $0x3,%rax
* 28:	42 0f b6 04 38       	movzbl (%rax,%r15,1),%eax <-- trapping instruction
  2d:	84 c0                	test   %al,%al
  2f:	0f 85 99 02 00 00    	jne    0x2ce
  35:	0f b6 6d 00          	movzbl 0x0(%rbp),%ebp
  39:	48 8b 44 24 58       	mov    0x58(%rsp),%rax