=============================
[ BUG: Invalid wait context ]
syzkaller #0 Not tainted
-----------------------------
udevd/5293 is trying to lock:
ffff8880127edbb0 (&gpc->lock){....}-{3:3}, at: kvm_xen_set_evtchn_fast+0x1f4/0x9a0 arch/x86/kvm/xen.c:1822
other info that might help us debug this:
context-{2:2}
3 locks held by udevd/5293:
 #0: ffff888012dd8450 (sb_writers#5){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2733 [inline]
 #0: ffff888012dd8450 (sb_writers#5){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683
 #1: ffff88804ea88890 (&sb->s_type->i_mutex_key#15){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
 #1: ffff88804ea88890 (&sb->s_type->i_mutex_key#15){+.+.}-{4:4}, at: shmem_file_write_iter+0x7f/0x120 mm/shmem.c:3414
 #2: ffff8880127ee110 (&kvm->srcu){.?.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:187 [inline]
 #2: ffff8880127ee110 (&kvm->srcu){.?.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:294 [inline]
 #2: ffff8880127ee110 (&kvm->srcu){.?.+}-{0:0}, at: kvm_xen_set_evtchn_fast+0x1bc/0x9a0 arch/x86/kvm/xen.c:1820
stack backtrace:
CPU: 0 UID: 0 PID: 5293 Comm: udevd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
 <IRQ>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_lock_invalid_wait_context kernel/locking/lockdep.c:4830 [inline]
 check_wait_context kernel/locking/lockdep.c:4902 [inline]
 __lock_acquire+0xe39/0x2cf0 kernel/locking/lockdep.c:5187
 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
 __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:174 [inline]
 _raw_read_lock_irqsave+0x48/0x60 kernel/locking/spinlock.c:240
 kvm_xen_set_evtchn_fast+0x1f4/0x9a0 arch/x86/kvm/xen.c:1822
 xen_timer_callback+0x109/0x220 arch/x86/kvm/xen.c:140
 __run_hrtimer kernel/time/hrtimer.c:2032 [inline]
 __hrtimer_run_queues+0x371/0xa10 kernel/time/hrtimer.c:2096
 hrtimer_interrupt+0x448/0x910 kernel/time/hrtimer.c:2215
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline]
 __sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1068
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
 sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1062
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:noop_dirty_folio+0x0/0x130 mm/page-writeback.c:2602
Code: ff 4c 89 e7 e8 21 ad 2b 00 e9 37 fc ff ff 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 41 57 41 56 41 55 41 54 53 48 89 f3 49 bf 00 00 00 00
RSP: 0018:ffffc9000dc6fac8 EFLAGS: 00000246
RAX: 1ffffffff17f1a7e RBX: ffffea000127cb80 RCX: ffff88801afca540
RDX: 0000000000000000 RSI: ffffea000127cb80 RDI: ffff88804ea88968
RBP: dffffc0000000000 R08: ffffea000127cb87 R09: 1ffffd400024f970
R10: dffffc0000000000 R11: ffffffff820a9a30 R12: 0000000000000026
R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffd400024f971
 shmem_write_end+0x425/0x5d0 mm/shmem.c:3281
 generic_perform_write+0x612/0x8f0 mm/filemap.c:4385
 shmem_file_write_iter+0xf8/0x120 mm/shmem.c:3424
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x612/0xba0 fs/read_write.c:687
 ksys_write+0x150/0x270 fs/read_write.c:739
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4eb6ea7407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007fffbb741dd0 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f4eb7632880 RCX: 00007f4eb6ea7407
RDX: 0000000000000026 RSI: 00005650343c1650 RDI: 0000000000000009
RBP: 00005650343c1650 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000026
R13: 00005650343bbb50 R14: 00007f4eb6fefea0 R15: 00005650226599dd
 </TASK>
----------------
Code disassembly (best guess):
   0:	ff 4c 89 e7          	decl   -0x19(%rcx,%rcx,4)
   4:	e8 21 ad 2b 00       	call   0x2bad2a
   9:	e9 37 fc ff ff       	jmp    0xfffffc45
   e:	66 66 66 2e 0f 1f 84 	data16 data16 cs nopw 0x0(%rax,%rax,1)
  15:	00 00 00 00 00
  1a:	90                   	nop
  1b:	90                   	nop
  1c:	90                   	nop
  1d:	90                   	nop
  1e:	90                   	nop
  1f:	90                   	nop
  20:	90                   	nop
  21:	90                   	nop
  22:	90                   	nop
  23:	90                   	nop
  24:	90                   	nop
  25:	90                   	nop
  26:	90                   	nop
  27:	90                   	nop
  28:	90                   	nop
  29:	90                   	nop
* 2a:	f3 0f 1e fa          	endbr64 <-- trapping instruction
  2e:	41 57                	push   %r15
  30:	41 56                	push   %r14
  32:	41 55                	push   %r13
  34:	41 54                	push   %r12
  36:	53                   	push   %rbx
  37:	48 89 f3             	mov    %rsi,%rbx
  3a:	49                   	rex.WB
  3b:	bf 00 00 00 00       	mov    $0x0,%edi