============================================ WARNING: possible recursive locking detected 5.16.0-rc2-next-20211125-syzkaller #0 Not tainted -------------------------------------------- kworker/u4:5/1084 is trying to acquire lock: ffff888084c35130 (&runtime->sleep){..-.}-{2:2}, at: io_poll_double_wake+0x2be/0x820 fs/io_uring.c:5461 but task is already holding lock: ffff888084c37130 (&runtime->sleep){..-.}-{2:2}, at: __wake_up_common_lock+0xb4/0x130 kernel/sched/wait.c:137 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&runtime->sleep); lock(&runtime->sleep); *** DEADLOCK *** May be due to missing lock nesting notation 5 locks held by kworker/u4:5/1084: #0: ffff88814a669938 ((wq_completion)bat_events){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff88814a669938 ((wq_completion)bat_events){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff88814a669938 ((wq_completion)bat_events){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline] #0: ffff88814a669938 ((wq_completion)bat_events){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:635 [inline] #0: ffff88814a669938 ((wq_completion)bat_events){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:662 [inline] #0: ffff88814a669938 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_one_work+0x896/0x1690 kernel/workqueue.c:2270 #1: ffffc90004cffdb0 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_one_work+0x8ca/0x1690 kernel/workqueue.c:2274 #2: ffffffff8bb83220 (rcu_read_lock){....}-{1:2}, at: batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:410 [inline] #2: ffffffff8bb83220 (rcu_read_lock){....}-{1:2}, at: batadv_nc_worker+0xf3/0xfa0 net/batman-adv/network-coding.c:723 #3: ffff888022a0f110 (&group->lock){..-.}-{2:2}, at: _snd_pcm_stream_lock_irqsave+0x9f/0xd0 sound/core/pcm_native.c:170 #4: ffff888084c37130 (&runtime->sleep){..-.}-{2:2}, at: __wake_up_common_lock+0xb4/0x130 kernel/sched/wait.c:137 stack backtrace: CPU: 0 PID: 1084 Comm: kworker/u4:5 Not tainted 5.16.0-rc2-next-20211125-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker 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_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:162 io_poll_double_wake+0x2be/0x820 fs/io_uring.c:5461 __wake_up_common+0x147/0x650 kernel/sched/wait.c:108 __wake_up_common_lock+0xd0/0x130 kernel/sched/wait.c:138 snd_pcm_update_state+0x46a/0x540 sound/core/pcm_lib.c:204 snd_pcm_update_hw_ptr0+0xa75/0x1a50 sound/core/pcm_lib.c:465 snd_pcm_period_elapsed_under_stream_lock+0x15a/0x230 sound/core/pcm_lib.c:1817 snd_pcm_period_elapsed+0x28/0x50 sound/core/pcm_lib.c:1849 dummy_hrtimer_callback+0x94/0x1b0 sound/drivers/dummy.c:377 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x609/0xe50 kernel/time/hrtimer.c:1749 hrtimer_run_softirq+0x17b/0x360 kernel/time/hrtimer.c:1766 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:637 irq_exit_rcu+0x5/0x20 kernel/softirq.c:649 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:lock_acquire+0x1ef/0x510 kernel/locking/lockdep.c:5605 Code: 9f a5 7e 83 f8 01 0f 85 b4 02 00 00 9c 58 f6 c4 02 0f 85 9f 02 00 00 48 83 7c 24 08 00 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 8b 84 24 RSP: 0018:ffffc90004cffba0 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 1ffff9200099ff76 RCX: 9b633d47e54f63ec RDX: 1ffff1100394689c RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8ff81947 R10: fffffbfff1ff0328 R11: 0000000000000000 R12: 0000000000000002 R13: 0000000000000000 R14: ffffffff8bb83220 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:268 [inline] rcu_read_lock include/linux/rcupdate.h:694 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline] batadv_nc_worker+0x12d/0xfa0 net/batman-adv/network-coding.c:723 process_one_work+0x9b2/0x1690 kernel/workqueue.c:2299 worker_thread+0x658/0x11f0 kernel/workqueue.c:2446 kthread+0x405/0x4f0 kernel/kthread.c:345 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. hrtimer: interrupt took 27709 ns ---------------- Code disassembly (best guess): 0: 9f lahf 1: a5 movsl %ds:(%rsi),%es:(%rdi) 2: 7e 83 jle 0xffffff87 4: f8 clc 5: 01 0f add %ecx,(%rdi) 7: 85 b4 02 00 00 9c 58 test %esi,0x589c0000(%rdx,%rax,1) e: f6 c4 02 test $0x2,%ah 11: 0f 85 9f 02 00 00 jne 0x2b6 17: 48 83 7c 24 08 00 cmpq $0x0,0x8(%rsp) 1d: 74 01 je 0x20 1f: fb sti 20: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 27: fc ff df * 2a: 48 01 c3 add %rax,%rbx <-- trapping instruction 2d: 48 c7 03 00 00 00 00 movq $0x0,(%rbx) 34: 48 c7 43 08 00 00 00 movq $0x0,0x8(%rbx) 3b: 00 3c: 48 rex.W 3d: 8b .byte 0x8b 3e: 84 .byte 0x84 3f: 24 .byte 0x24