============================================ WARNING: possible recursive locking detected 5.16.0-rc2-syzkaller #0 Not tainted -------------------------------------------- syz-executor.2/31074 is trying to acquire lock: ffff88802b48b418 (&ctx->timeout_lock){+.+.}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:374 [inline] ffff88802b48b418 (&ctx->timeout_lock){+.+.}-{2:2}, at: io_flush_timeouts fs/io_uring.c:1587 [inline] ffff88802b48b418 (&ctx->timeout_lock){+.+.}-{2:2}, at: __io_commit_cqring_flush+0x108/0x50d fs/io_uring.c:1618 but task is already holding lock: ffff88802b48b418 (&ctx->timeout_lock){+.+.}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:374 [inline] ffff88802b48b418 (&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.2/31074: #0: ffff88802b48b3d8 (&ctx->completion_lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline] #0: ffff88802b48b3d8 (&ctx->completion_lock){+.+.}-{2:2}, at: io_poll_remove_all+0x48/0x235 fs/io_uring.c:5701 #1: ffff88802b48b418 (&ctx->timeout_lock){+.+.}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:374 [inline] #1: ffff88802b48b418 (&ctx->timeout_lock){+.+.}-{2:2}, at: io_poll_remove_all+0x50/0x235 fs/io_uring.c:5702 stack backtrace: CPU: 1 PID: 31074 Comm: syz-executor.2 Not tainted 5.16.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __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_ring_ctx_wait_and_kill+0x1cc/0x322 fs/io_uring.c:9534 io_uring_release+0x42/0x46 fs/io_uring.c:9554 __fput+0x286/0x9f0 fs/file_table.c:280 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop kernel/entry/common.c:175 [inline] exit_to_user_mode_prepare+0x27e/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_fast_syscall_32+0x72/0xf0 arch/x86/entry/common.c:181 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c RIP: 0023:0xf6f2b549 Code: 03 74 c0 01 10 05 03 74 b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000f452559c EFLAGS: 00000206 ORIG_RAX: 00000000000000c0 RAX: 0000000020400000 RBX: 0000000020400000 RCX: 0000000000008000 RDX: 0000000000000003 RSI: 0000000000008011 RDI: 0000000000000003 RBP: 0000000000010000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 ---------------- Code disassembly (best guess): 0: 03 74 c0 01 add 0x1(%rax,%rax,8),%esi 4: 10 05 03 74 b8 01 adc %al,0x1b87403(%rip) # 0x1b8740d a: 10 06 adc %al,(%rsi) c: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi 10: 10 07 adc %al,(%rdi) 12: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi 16: 10 08 adc %cl,(%rax) 18: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi 1c: 00 00 add %al,(%rax) 1e: 00 00 add %al,(%rax) 20: 00 51 52 add %dl,0x52(%rcx) 23: 55 push %rbp 24: 89 e5 mov %esp,%ebp 26: 0f 34 sysenter 28: cd 80 int $0x80 * 2a: 5d pop %rbp <-- trapping instruction 2b: 5a pop %rdx 2c: 59 pop %rcx 2d: c3 retq 2e: 90 nop 2f: 90 nop 30: 90 nop 31: 90 nop 32: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi 39: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi