rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P2971/1:b..l P29980/1:b..l (detected by 1, t=10502 jiffies, g=228221, q=159) task:kworker/u4:16 state:R running task stack:23600 pid:29980 ppid: 2 flags:0x00004000 Workqueue: bat_events batadv_nc_worker Call Trace: context_switch kernel/sched/core.c:4972 [inline] __schedule+0xb72/0x1460 kernel/sched/core.c:6253 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6668 irqentry_exit+0x56/0x90 kernel/entry/common.c:425 asm_sysvec_apic_timer_interrupt+0x12/0x20 RIP: 0010:rcu_lock_acquire+0xa/0x30 include/linux/rcupdate.h:268 Code: 72 ff ff ff 48 89 df e8 a4 5f e6 f7 e9 65 ff ff ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 e8 db f0 9b f7 e8 d6 f0 9b f7 <48> c7 c7 00 de b1 8c 31 f6 31 d2 b9 02 00 00 00 45 31 c0 45 31 c9 RSP: 0018:ffffc90004307b88 EFLAGS: 00000293 RAX: ffffffff89e88d3a RBX: ffff8880228d6880 RCX: ffff888058ca1d00 RDX: 0000000000000000 RSI: 0000000000000080 RDI: ffffffff8cb1de00 RBP: 0000000000000000 R08: ffffffff89e882b4 R09: fffffbfff1ff3df8 R10: fffffbfff1ff3df8 R11: 0000000000000000 R12: ffff8880228d6890 R13: ffff88805cad8c80 R14: ffff8880791b8000 R15: ffffffff89e885b0 rcu_read_lock include/linux/rcupdate.h:688 [inline] batadv_nc_process_nc_paths+0xc6/0x360 net/batman-adv/network-coding.c:691 batadv_nc_worker+0x3de/0x5b0 net/batman-adv/network-coding.c:732 process_one_work+0x853/0x1140 kernel/workqueue.c:2298 worker_thread+0xac1/0x1320 kernel/workqueue.c:2445 kthread+0x468/0x490 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 task:udevd state:R running task stack:22192 pid: 2971 ppid: 1 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4972 [inline] __schedule+0xb72/0x1460 kernel/sched/core.c:6253 preempt_schedule_common kernel/sched/core.c:6419 [inline] preempt_schedule+0x14d/0x190 kernel/sched/core.c:6444 preempt_schedule_thunk+0x16/0x18 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x36/0x40 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:389 [inline] lockref_put_or_lock+0x6f/0xb0 lib/lockref.c:178 fast_dput fs/dcache.c:750 [inline] dput+0x2f5/0x6e0 fs/dcache.c:875 __fput+0x5ed/0x870 fs/file_table.c:293 task_work_run+0x146/0x1c0 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+0x209/0x220 kernel/entry/common.c:207 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline] syscall_exit_to_user_mode+0x2e/0x70 kernel/entry/common.c:300 do_syscall_64+0x53/0xd0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f037e447fc3 RSP: 002b:00007fff2777f998 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f037e447fc3 RDX: 0000000000000000 RSI: 000000000000125f RDI: 000000000000000c RBP: 000055ee69700a80 R08: 0000000000000008 R09: 000055ee69717a60 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff2777fb88 R13: 000000000000000c R14: 0000000000000000 R15: 0000000000000000 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g228221 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=129037 rcu: rcu_preempt kthread starved for 10502 jiffies! g228221 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:I stack:26576 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4972 [inline] __schedule+0xb72/0x1460 kernel/sched/core.c:6253 schedule+0x12b/0x1f0 kernel/sched/core.c:6326 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x1fd/0x770 kernel/rcu/tree.c:1955 rcu_gp_kthread+0xa5/0x350 kernel/rcu/tree.c:2128 kthread+0x468/0x490 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 19332 Comm: syz-executor.2 Not tainted 5.16.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:lock_is_held_type+0x127/0x190 kernel/locking/lockdep.c:5682 Code: 48 c7 c7 40 18 6f 8a e8 e7 10 00 00 b8 ff ff ff ff 65 0f c1 05 ea 1c f8 75 83 f8 01 75 40 48 c7 04 24 00 00 00 00 9c 8f 04 24 04 24 00 02 00 00 75 46 41 f7 c4 00 02 00 00 74 01 fb 65 48 8b RSP: 0018:ffffc90000007c18 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000080010003 RDX: ffff88807d6cba00 RSI: 0000000000010003 RDI: 0000000000000000 RBP: 0000000000000001 R08: ffffffff8173bb35 R09: fffffbfff1bfd566 R10: fffffbfff1bfd566 R11: 0000000000000000 R12: 0000000000000046 R13: ffff88807d6cba00 R14: 00000000ffffffff R15: ffffffff8cb1dd60 FS: 00007fe684fe2700(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000040 CR3: 0000000024a19000 CR4: 00000000003506f0 Call Trace: lock_is_held include/linux/lockdep.h:283 [inline] rcu_read_lock_sched_held+0x89/0x130 kernel/rcu/update.c:125 trace_hrtimer_cancel+0xab/0x260 include/trace/events/timer.h:290 debug_deactivate kernel/time/hrtimer.c:482 [inline] __run_hrtimer kernel/time/hrtimer.c:1653 [inline] __hrtimer_run_queues+0x301/0xa60 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x3b3/0x1040 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] __sysvec_apic_timer_interrupt+0xf9/0x270 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xd4/0x130 kernel/locking/spinlock.c:194 Code: 9c 8f 44 24 20 42 80 3c 23 00 74 08 4c 89 f7 e8 02 d9 c1 f7 f6 44 24 21 02 75 4e 41 f7 c7 00 02 00 00 74 01 fb bf 01 00 00 00 87 12 4d f7 65 8b 05 d8 5b f5 75 85 c0 74 3f 48 c7 04 24 0e 36 RSP: 0018:ffffc900045afca0 EFLAGS: 00000206 RAX: 8fb0b90288256300 RBX: 1ffff920008b5f98 RCX: ffffffff90bb6903 RDX: dffffc0000000000 RSI: 0000000000000001 RDI: 0000000000000001 RBP: ffffc900045afd30 R08: ffffffff818b1ab0 R09: fffffbfff1966079 R10: fffffbfff1966079 R11: 0000000000000000 R12: dffffc0000000000 R13: 1ffff920008b5f94 R14: ffffc900045afcc0 R15: 0000000000000246 do_settimeofday64+0x68b/0x810 kernel/time/timekeeping.c:1323 __do_sys_clock_settime kernel/time/posix-timers.c:1079 [inline] __se_sys_clock_settime kernel/time/posix-timers.c:1067 [inline] __x64_sys_clock_settime+0x23d/0x280 kernel/time/posix-timers.c:1067 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fe68666ce99 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:00007fe684fe2168 EFLAGS: 00000246 ORIG_RAX: 00000000000000e3 RAX: ffffffffffffffda RBX: 00007fe68677ff60 RCX: 00007fe68666ce99 RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000000 RBP: 00007fe6866c6ff1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff13bf2c3f R14: 00007fe684fe2300 R15: 0000000000022000 ---------------- Code disassembly (best guess), 3 bytes skipped: 0: ff 48 89 decl -0x77(%rax) 3: df e8 fucomip %st(0),%st 5: a4 movsb %ds:(%rsi),%es:(%rdi) 6: 5f pop %rdi 7: e6 f7 out %al,$0xf7 9: e9 65 ff ff ff jmpq 0xffffff73 e: 66 2e 0f 1f 84 00 00 nopw %cs:0x0(%rax,%rax,1) 15: 00 00 00 18: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 1d: e8 db f0 9b f7 callq 0xf79bf0fd 22: e8 d6 f0 9b f7 callq 0xf79bf0fd * 27: 48 c7 c7 00 de b1 8c mov $0xffffffff8cb1de00,%rdi <-- trapping instruction 2e: 31 f6 xor %esi,%esi 30: 31 d2 xor %edx,%edx 32: b9 02 00 00 00 mov $0x2,%ecx 37: 45 31 c0 xor %r8d,%r8d 3a: 45 31 c9 xor %r9d,%r9d