rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4960/1:b..l P737/1:b..l (detected by 1, t=10502 jiffies, g=10677, q=231) task:kworker/u4:5 state:R running task stack: 0 pid: 737 ppid: 2 flags:0x00000008 Workqueue: bat_events batadv_nc_worker Call trace: __switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518 context_switch kernel/sched/core.c:5030 [inline] __schedule+0xf10/0x1e48 kernel/sched/core.c:6376 preempt_schedule_irq+0x90/0x274 kernel/sched/core.c:6780 arm64_preempt_schedule_irq+0x174/0x2c4 arch/arm64/kernel/entry-common.c:260 el1_interrupt+0x40/0x58 arch/arm64/kernel/entry-common.c:463 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:470 el1h_64_irq+0x78/0x7c arch/arm64/kernel/entry.S:580 check_kcov_mode kernel/kcov.c:163 [inline] write_comp_data kernel/kcov.c:218 [inline] __sanitizer_cov_trace_const_cmp4+0x5c/0xb0 kernel/kcov.c:284 process_one_work+0x790/0x11b8 kernel/workqueue.c:2310 worker_thread+0x910/0x1034 kernel/workqueue.c:2457 kthread+0x37c/0x45c kernel/kthread.c:334 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870 task:syz-executor.1 state:R running task stack: 0 pid: 4960 ppid: 3978 flags:0x00000004 Call trace: __switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518 context_switch kernel/sched/core.c:5030 [inline] __schedule+0xf10/0x1e48 kernel/sched/core.c:6376 preempt_schedule_common+0x140/0x260 kernel/sched/core.c:6552 preempt_schedule+0x64/0x84 kernel/sched/core.c:6577 __local_bh_enable_ip+0x254/0x470 kernel/softirq.c:390 local_bh_enable+0x28/0x1d0 include/linux/bottom_half.h:32 rcu_read_unlock_bh include/linux/rcupdate.h:809 [inline] ip_finish_output2+0xe78/0x131c net/ipv4/ip_output.c:229 __ip_finish_output+0x1b0/0x458 ip_finish_output+0x40/0x218 net/ipv4/ip_output.c:316 NF_HOOK_COND include/linux/netfilter.h:291 [inline] ip_output+0x330/0x49c net/ipv4/ip_output.c:430 dst_output include/net/dst.h:443 [inline] ip_local_out net/ipv4/ip_output.c:126 [inline] __ip_queue_xmit+0xe70/0x1930 net/ipv4/ip_output.c:532 ip_queue_xmit+0x5c/0x78 net/ipv4/ip_output.c:546 __tcp_transmit_skb+0x1944/0x31e8 net/ipv4/tcp_output.c:1402 tcp_transmit_skb net/ipv4/tcp_output.c:1420 [inline] tcp_connect+0x19fc/0x3e34 net/ipv4/tcp_output.c:3889 tcp_v4_connect+0xc48/0x15fc net/ipv4/tcp_ipv4.c:314 __inet_stream_connect+0x204/0xc00 net/ipv4/af_inet.c:669 inet_stream_connect+0x74/0xb0 net/ipv4/af_inet.c:733 __sys_connect_file net/socket.c:1918 [inline] __sys_connect+0x268/0x290 net/socket.c:1935 __do_sys_connect net/socket.c:1945 [inline] __se_sys_connect net/socket.c:1942 [inline] __arm64_sys_connect+0x7c/0x94 net/socket.c:1942 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584 rcu: rcu_preempt kthread starved for 10508 jiffies! g10677 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack: 0 pid: 15 ppid: 2 flags:0x00000008 Call trace: __switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518 context_switch kernel/sched/core.c:5030 [inline] __schedule+0xf10/0x1e48 kernel/sched/core.c:6376 schedule+0x11c/0x1c8 kernel/sched/core.c:6459 schedule_timeout+0x1d8/0x344 kernel/time/timer.c:1914 rcu_gp_fqs_loop+0x26c/0x13d4 kernel/rcu/tree.c:1972 rcu_gp_kthread+0xc4/0x2c4 kernel/rcu/tree.c:2145 kthread+0x37c/0x45c kernel/kthread.c:334 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870 rcu: Stack dump where RCU GP kthread last ran: Task dump for CPU 0: task:syz-executor.2 state:R running task stack: 0 pid: 4961 ppid: 4333 flags:0x00000001 Call trace: __switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518 0xffff0000d9801b40