rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 0, t=10502 jiffies, g=247065, q=137 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4295223896-4295213394), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10502 jiffies! g247065 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:28656 pid: 16 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5146 [inline] __schedule+0xa00/0x4b50 kernel/sched/core.c:6458 schedule+0xd2/0x1f0 kernel/sched/core.c:6530 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1935 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1999 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2187 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:302 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: 26867 Comm: kworker/u4:1 Not tainted 5.19.0-rc5-syzkaller-00187-ge8a4e1c1bb69 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022 Workqueue: bat_events batadv_nc_worker RIP: 0010:__kasan_check_read+0x4/0x10 mm/kasan/shadow.c:31 Code: 0f 0b 48 83 c4 60 5b 5d 41 5c c3 48 05 00 80 00 00 48 89 fb 48 39 c7 0f 82 65 7f 6d 07 eb e1 cc cc cc cc cc cc cc 48 8b 0c 24 <89> f6 31 d2 e9 b3 fa ff ff 0f 1f 00 48 8b 0c 24 89 f6 ba 01 00 00 RSP: 0018:ffffc900001e0d18 EFLAGS: 00000046 RAX: 0000000000000007 RBX: 0000000000000016 RCX: ffffffff815ed2b0 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff91124550 RBP: ffffffff91124550 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: dffffc0000000000 R13: ffffffff89ced860 R14: 1ffff9200003c1ad R15: ffff888016d29b40 FS: 0000000000000000(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fab0e3691b8 CR3: 0000000061fc9000 CR4: 0000000000350ee0 Call Trace: instrument_atomic_read include/linux/instrumented.h:71 [inline] atomic_read include/linux/atomic/atomic-instrumented.h:27 [inline] queued_spin_is_locked include/asm-generic/qspinlock.h:57 [inline] debug_spin_unlock kernel/locking/spinlock_debug.c:100 [inline] do_raw_spin_unlock+0x50/0x230 kernel/locking/spinlock_debug.c:140 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:150 [inline] _raw_spin_unlock_irqrestore+0x1e/0x70 kernel/locking/spinlock.c:194 debug_object_deactivate lib/debugobjects.c:754 [inline] debug_object_deactivate+0x264/0x300 lib/debugobjects.c:720 debug_hrtimer_deactivate kernel/time/hrtimer.c:425 [inline] debug_deactivate kernel/time/hrtimer.c:481 [inline] __run_hrtimer kernel/time/hrtimer.c:1653 [inline] __hrtimer_run_queues+0x3f8/0xe50 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1112 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:lock_acquire+0x1ef/0x570 kernel/locking/lockdep.c:5633 Code: 1e a4 7e 83 f8 01 0f 85 e8 02 00 00 9c 58 f6 c4 02 0f 85 fb 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:ffffc900030efb98 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 1ffff9200061df75 RCX: 6efa2c88428065f8 RDX: 1ffff1100ead38ab RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff90680907 R10: fffffbfff20d0120 R11: 0000000000000001 R12: 0000000000000002 R13: 0000000000000000 R14: ffffffff8bd86660 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:269 [inline] rcu_read_lock include/linux/rcupdate.h:695 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0x12d/0xfa0 net/batman-adv/network-coding.c:719 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:302 ---------------- Code disassembly (best guess): 0: 0f 0b ud2 2: 48 83 c4 60 add $0x60,%rsp 6: 5b pop %rbx 7: 5d pop %rbp 8: 41 5c pop %r12 a: c3 retq b: 48 05 00 80 00 00 add $0x8000,%rax 11: 48 89 fb mov %rdi,%rbx 14: 48 39 c7 cmp %rax,%rdi 17: 0f 82 65 7f 6d 07 jb 0x76d7f82 1d: eb e1 jmp 0x0 1f: cc int3 20: cc int3 21: cc int3 22: cc int3 23: cc int3 24: cc int3 25: cc int3 26: 48 8b 0c 24 mov (%rsp),%rcx * 2a: 89 f6 mov %esi,%esi <-- trapping instruction 2c: 31 d2 xor %edx,%edx 2e: e9 b3 fa ff ff jmpq 0xfffffae6 33: 0f 1f 00 nopl (%rax) 36: 48 8b 0c 24 mov (%rsp),%rcx 3a: 89 f6 mov %esi,%esi 3c: ba .byte 0xba 3d: 01 00 add %eax,(%rax)