============================================
WARNING: possible recursive locking detected
5.16.0-rc2-syzkaller #0 Not tainted
--------------------------------------------
syz-executor.3/24468 is trying to acquire lock:
ffff8880845f2418 (&ctx->timeout_lock){+.+.}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:374 [inline]
ffff8880845f2418 (&ctx->timeout_lock){+.+.}-{2:2}, at: io_flush_timeouts fs/io_uring.c:1587 [inline]
ffff8880845f2418 (&ctx->timeout_lock){+.+.}-{2:2}, at: __io_commit_cqring_flush+0x108/0x50d fs/io_uring.c:1618

but task is already holding lock:
ffff8880845f2418 (&ctx->timeout_lock){+.+.}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:374 [inline]
ffff8880845f2418 (&ctx->timeout_lock){+.+.}-{2:2}, at: io_poll_remove_all+0x50/0x235 fs/io_uring.c:5702

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&ctx->timeout_lock);
  lock(&ctx->timeout_lock);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

2 locks held by syz-executor.3/24468:
 #0: ffff8880845f23d8 (&ctx->completion_lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline]
 #0: ffff8880845f23d8 (&ctx->completion_lock){+.+.}-{2:2}, at: io_poll_remove_all+0x48/0x235 fs/io_uring.c:5701
 #1: ffff8880845f2418 (&ctx->timeout_lock){+.+.}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:374 [inline]
 #1: ffff8880845f2418 (&ctx->timeout_lock){+.+.}-{2:2}, at: io_poll_remove_all+0x50/0x235 fs/io_uring.c:5702

stack backtrace:
CPU: 0 PID: 24468 Comm: syz-executor.3 Not tainted 5.16.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 print_deadlock_bug kernel/locking/lockdep.c:2956 [inline]
 check_deadlock kernel/locking/lockdep.c:2999 [inline]
 validate_chain kernel/locking/lockdep.c:3788 [inline]
 __lock_acquire.cold+0x149/0x3ab kernel/locking/lockdep.c:5027
 lock_acquire kernel/locking/lockdep.c:5637 [inline]
 lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5602
 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline]
 _raw_spin_lock_irq+0x32/0x50 kernel/locking/spinlock.c:170
 spin_lock_irq include/linux/spinlock.h:374 [inline]
 io_flush_timeouts fs/io_uring.c:1587 [inline]
 __io_commit_cqring_flush+0x108/0x50d fs/io_uring.c:1618
 io_commit_cqring fs/io_uring.c:1626 [inline]
 io_poll_remove_one fs/io_uring.c:5684 [inline]
 io_poll_remove_one.cold+0xd/0x12 fs/io_uring.c:5674
 io_poll_remove_all+0x1af/0x235 fs/io_uring.c:5709
 io_uring_try_cancel_requests+0x66d/0x717 fs/io_uring.c:9668
 io_uring_cancel_generic+0x3b8/0x690 fs/io_uring.c:9833
 io_uring_files_cancel include/linux/io_uring.h:16 [inline]
 do_exit+0x60c/0x2b40 kernel/exit.c:787
 do_group_exit+0x125/0x310 kernel/exit.c:929
 get_signal+0x47d/0x2220 kernel/signal.c:2852
 arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:868
 handle_signal_work kernel/entry/common.c:148 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:172 [inline]
 exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:207
 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]
 syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300
 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fbebf3c4ae9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fbebc919188 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa
RAX: 0000000000000495 RBX: 00007fbebf4d8020 RCX: 00007fbebf3c4ae9
RDX: 0000000000000000 RSI: 000000000000450e RDI: 0000000000000007
RBP: 00007fbebf41ef6d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc2444cc0f R14: 00007fbebc919300 R15: 0000000000022000
 </TASK>