rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P742/1:b..l (detected by 0, t=10502 jiffies, g=419925, q=252) task:kworker/u4:3 state:R running task stack:23488 pid: 742 ppid: 2 flags:0x00004000 Workqueue: bat_events batadv_nc_worker Call Trace: context_switch kernel/sched/core.c:5073 [inline] __schedule+0xa9a/0x4cc0 kernel/sched/core.c:6388 preempt_schedule_irq+0x4e/0x90 kernel/sched/core.c:6696 irqentry_exit+0x31/0x80 kernel/entry/common.c:428 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:lock_acquire+0x1ef/0x510 kernel/locking/lockdep.c:5609 Code: a5 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:ffffc90003467b28 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 1ffff9200068cf67 RCX: 49c910a19c8edcc7 RDX: 1ffff11003729153 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff90037907 R10: fffffbfff2006f20 R11: 0000000000000001 R12: 0000000000000002 R13: 0000000000000000 R14: ffffffff8bd7f2e0 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:268 [inline] rcu_read_lock include/linux/rcupdate.h:694 [inline] batadv_nc_process_nc_paths.part.0+0xec/0x3c0 net/batman-adv/network-coding.c:687 batadv_nc_process_nc_paths net/batman-adv/network-coding.c:679 [inline] batadv_nc_worker+0xc46/0xfa0 net/batman-adv/network-coding.c:728 process_one_work+0x996/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g419925 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=265038 rcu: rcu_preempt kthread starved for 10502 jiffies! g419925 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1 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:28944 pid: 16 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5073 [inline] __schedule+0xa9a/0x4cc0 kernel/sched/core.c:6388 schedule+0xd2/0x1f0 kernel/sched/core.c:6460 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1884 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1971 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2144 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 12244 Comm: syz-executor.4 Not tainted 5.18.0-rc3-syzkaller-00007-g559089e0a93d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:match_held_lock+0x1/0xc0 kernel/locking/lockdep.c:5087 Code: ee 48 c7 c7 80 45 cc 89 e8 9c 40 bc ff 48 c7 c7 e0 45 cc 89 e8 90 40 bc ff e8 06 37 cc ff 31 c0 5d c3 0f 1f 80 00 00 00 00 53 <48> 89 fb 48 83 ec 08 48 39 77 10 74 6a 66 f7 47 22 f0 ff 74 5a 48 RSP: 0018:ffffc90000ff8d00 EFLAGS: 00000093 RAX: 000000000000000a RBX: 0000000000000002 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff8bd7f220 RDI: ffff888075cfed70 RBP: ffffffff8bd7f220 R08: 0000000000000000 R09: ffffffff8db6cb57 R10: fffffbfff1b6d96a R11: 0000000000000000 R12: ffff888075cfe2c0 R13: ffff888075cfed20 R14: 00000000ffffffff R15: ffff888075cfed70 FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000040 CR3: 000000000ba8e000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 000000000000003b DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: __lock_is_held kernel/locking/lockdep.c:5382 [inline] lock_is_held_type+0xa7/0x140 kernel/locking/lockdep.c:5684 lock_is_held include/linux/lockdep.h:283 [inline] rcu_read_lock_sched_held+0x3a/0x70 kernel/rcu/update.c:125 trace_lock_release include/trace/events/lock.h:58 [inline] lock_release+0x522/0x720 kernel/locking/lockdep.c:5652 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline] _raw_spin_unlock_irqrestore+0x16/0x70 kernel/locking/spinlock.c:194 __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+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:lock_release+0x1e/0x720 kernel/locking/lockdep.c:5649 Code: 6d fd ff ff 0f 1f 84 00 00 00 00 00 48 b8 00 00 00 00 00 fc ff df 41 57 41 56 41 55 41 54 49 89 fc 55 53 48 81 ec 90 00 00 00 <48> 8d 6c 24 10 48 89 74 24 08 48 c7 44 24 10 b3 8a b5 41 48 c1 ed RSP: 0018:ffffc900041af668 EFLAGS: 00000282 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff81ca82b9 RDX: 0000000000000000 RSI: ffffffff81c92799 RDI: ffffffff8bd7f2e0 RBP: ffffea00012e2480 R08: 0000000000000000 R09: ffffea00012e2487 R10: fffff9400025c490 R11: 0000000000000000 R12: ffffffff8bd7f2e0 R13: ffffea00012e2488 R14: 0000000000000000 R15: 0000000000000000 page_remove_rmap+0x318/0x1510 mm/rmap.c:1413 zap_pte_range mm/memory.c:1389 [inline] zap_pmd_range mm/memory.c:1497 [inline] zap_pud_range mm/memory.c:1526 [inline] zap_p4d_range mm/memory.c:1547 [inline] unmap_page_range+0xffa/0x3fa0 mm/memory.c:1568 unmap_single_vma+0x198/0x310 mm/memory.c:1613 unmap_vmas+0x16b/0x2f0 mm/memory.c:1645 exit_mmap+0x1c4/0x4a0 mm/mmap.c:3148 __mmput+0x122/0x4b0 kernel/fork.c:1183 mmput+0x56/0x60 kernel/fork.c:1205 exit_mm kernel/exit.c:510 [inline] do_exit+0xa12/0x2a00 kernel/exit.c:782 do_group_exit+0xd2/0x2f0 kernel/exit.c:925 get_signal+0x22df/0x24c0 kernel/signal.c:2864 arch_do_signal_or_restart+0x82/0x20f0 arch/x86/kernel/signal.c:867 exit_to_user_mode_loop kernel/entry/common.c:166 [inline] exit_to_user_mode_prepare+0x15f/0x250 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:294 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f348a2890e9 Code: Unable to access opcode bytes at RIP 0x7f348a2890bf. RSP: 002b:00007f348b3eb218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f348a39bf68 RCX: 00007f348a2890e9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f348a39bf68 RBP: 00007f348a39bf60 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f348a39bf6c R13: 00007ffe9a10b06f R14: 00007f348b3eb300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: a5 movsl %ds:(%rsi),%es:(%rdi) 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