rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P13136/1:b..l (detected by 1, t=10502 jiffies, g=245405, q=345) task:kworker/u4:9 state:R running task stack:24200 pid:13136 ppid: 2 flags:0x00004000 Workqueue: bat_events batadv_nc_worker Call Trace: context_switch kernel/sched/core.c:4972 [inline] __schedule+0xa9a/0x4940 kernel/sched/core.c:6253 preempt_schedule_irq+0x4e/0x90 kernel/sched/core.c:6668 irqentry_exit+0x31/0x80 kernel/entry/common.c:425 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: c3 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:ffffc900031efba0 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 1ffff9200063df76 RCX: 96ab8122bc4eac87 RDX: 1ffff11002f0b14b RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8ff72a07 R10: fffffbfff1fee540 R11: 0000000000000000 R12: 0000000000000002 R13: 0000000000000000 R14: ffffffff8bb83ca0 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:268 [inline] rcu_read_lock include/linux/rcupdate.h:688 [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:2298 worker_thread+0x658/0x11f0 kernel/workqueue.c:2445 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: rcu_preempt kthread timer wakeup didn't happen for 10493 jiffies! g245405 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=95393 rcu: rcu_preempt kthread starved for 10494 jiffies! g245405 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:28688 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4972 [inline] __schedule+0xa9a/0x4940 kernel/sched/core.c:6253 schedule+0xd2/0x260 kernel/sched/core.c:6326 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1955 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2128 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 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: 27161 Comm: syz-executor.1 Not tainted 5.16.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:_raw_spin_unlock_irqrestore+0x9/0x70 kernel/locking/spinlock.c:193 Code: fb bf 01 00 00 00 e8 06 fe 08 f8 65 8b 05 df 80 bb 76 85 c0 74 02 5d c3 e8 fb 55 b9 f7 5d c3 66 90 55 48 89 fd 48 83 c7 18 53 <48> 89 f3 48 8b 74 24 10 e8 fa be 15 f8 48 89 ef e8 42 35 16 f8 81 RSP: 0000:ffffc9000447fd70 EFLAGS: 00000086 RAX: dffffc0000000000 RBX: ffff888074e99340 RCX: 0000000000000000 RDX: 1ffff1100e9d326d RSI: 0000000000000046 RDI: ffff8880b9c2a418 RBP: ffff8880b9c2a400 R08: 0000000000000000 R09: 0000000019f16c01 R10: ffffffff8166dccb R11: 0000000000000000 R12: 1774e2d32ee9c5a6 R13: ffff8880b9c2a500 R14: ffff8880b9c2a400 R15: ffffffff875eb030 FS: 0000555557237400(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2c221000 CR3: 00000000463b7000 CR4: 0000000000350ef0 Call Trace: __run_hrtimer kernel/time/hrtimer.c:1681 [inline] __hrtimer_run_queues+0x51a/0xe50 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x40/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0033:0x7fc786d2eb99 Code: 3d ff ff ff 7e 0f 87 23 02 00 00 44 89 d0 c1 e8 10 44 31 d0 83 f0 3d 8d 04 c0 89 c7 c1 ef 04 31 f8 69 c0 2d eb d4 27 41 31 c0 e8 0f 41 31 c0 80 3d eb e7 09 01 00 0f 85 74 ff ff ff bd 01 00 RSP: 002b:00007fffca9f6ed0 EFLAGS: 00000282 RAX: 000000007c683e52 RBX: 00007fc786af8008 RCX: 0000001b2c220000 RDX: 0000001b2c221334 RSI: ffffffff83a3126a RDI: 000000000a0c020d RBP: 0000000000000001 R08: 00000000ffcb2c38 R09: 0000001b2c220220 R10: ffffffff83a31241 R11: 00000000d5eb101d R12: 000000000000d321 R13: 00007fc786e88000 R14: ffffffff83a3126a R15: 00007fc786e93ff0 ---------------- Code disassembly (best guess): 0: c3 retq 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