rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5357/1:b..l rcu: (detected by 0, t=10503 jiffies, g=77605, q=306 ncpus=2) task:kworker/u8:9 state:R running task stack:24320 pid:5357 tgid:5357 ppid:2 flags:0x00004000 Workqueue: bat_events batadv_nc_worker Call Trace: context_switch kernel/sched/core.c:5322 [inline] __schedule+0xef5/0x5750 kernel/sched/core.c:6682 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7004 irqentry_exit+0x36/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire.part.0+0x155/0x380 kernel/locking/lockdep.c:5790 Code: b8 ff ff ff ff 65 0f c1 05 f0 d5 97 7e 83 f8 01 0f 85 d0 01 00 00 9c 58 f6 c4 02 0f 85 e5 01 00 00 48 85 ed 0f 85 b6 01 00 00 <48> b8 00 00 00 00 00 fc ff df 48 01 c3 48 c7 03 00 00 00 00 48 c7 RSP: 0018:ffffc900048a7aa8 EFLAGS: 00000206 RAX: 0000000000000046 RBX: 1ffff92000914f56 RCX: 0000000000000001 RDX: 0000000000000001 RSI: ffffffff8b6cd340 RDI: ffffffff8bd1a800 RBP: 0000000000000200 R08: 0000000000000000 R09: fffffbfff2dc5388 R10: ffffffff96e29c47 R11: 0000000000000000 R12: 0000000000000000 R13: ffffffff8e1b8340 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:337 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0x16a/0x1060 net/batman-adv/network-coding.c:719 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: rcu_preempt kthread starved for 10530 jiffies! g77605 f0x0 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:27360 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5322 [inline] __schedule+0xef5/0x5750 kernel/sched/core.c:6682 __schedule_loop kernel/sched/core.c:6759 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6774 schedule_timeout+0x136/0x2a0 kernel/time/timer.c:2615 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2045 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2247 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 8399 Comm: syz.3.222 Not tainted 6.12.0-rc3-syzkaller-00087-gc964ced77262 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] RIP: 0010:cpumask_test_cpu include/linux/cpumask.h:570 [inline] RIP: 0010:cpu_online include/linux/cpumask.h:1117 [inline] RIP: 0010:trace_lock_release include/trace/events/lock.h:69 [inline] RIP: 0010:lock_release+0x9c/0x6f0 kernel/locking/lockdep.c:5836 Code: 00 31 c0 0f 1f 44 00 00 49 c7 c6 cc db 03 00 65 41 8b 2e 83 fd 07 0f 87 21 05 00 00 89 ed be 08 00 00 00 48 89 e8 48 c1 e8 06 <48> 8d 3c c5 c8 49 5f 90 e8 07 59 84 00 48 0f a3 2d 37 a4 f4 0e 0f RSP: 0018:ffffc90003be7c60 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 1ffff9200077cf8e RCX: ffffc9000fc56000 RDX: 0000000000040000 RSI: 0000000000000008 RDI: ffffffff8e1b8340 RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff8e1b8340 R13: ffff888078a3da00 R14: 000000000003dbcc R15: 0000000000000001 FS: 00007f216ab146c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f216ab14650 CR3: 0000000027a52000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_lock_release include/linux/rcupdate.h:347 [inline] rcu_read_unlock include/linux/rcupdate.h:880 [inline] group_send_sig_info+0xf7/0x300 kernel/signal.c:1446 bpf_send_signal_common+0x2e8/0x3a0 kernel/trace/bpf_trace.c:857 ____bpf_send_signal kernel/trace/bpf_trace.c:862 [inline] bpf_send_signal+0x19/0x30 kernel/trace/bpf_trace.c:860 bpf_prog_7ba5217f62dcd359+0x41/0x45 bpf_dispatcher_nop_func include/linux/bpf.h:1257 [inline] __bpf_prog_run include/linux/filter.h:701 [inline] bpf_prog_run include/linux/filter.h:708 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2318 [inline] bpf_trace_run2+0x231/0x590 kernel/trace/bpf_trace.c:2359 trace_sys_enter include/trace/events/syscalls.h:18 [inline] syscall_trace_enter+0x1b2/0x240 kernel/entry/common.c:61 syscall_enter_from_user_mode_work include/linux/entry-common.h:168 [inline] syscall_enter_from_user_mode include/linux/entry-common.h:198 [inline] do_syscall_64+0x1ee/0x250 arch/x86/entry/common.c:79 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2169d19959 Code: 64 c7 00 16 00 00 00 b8 ff ff ff ff c3 0f 1f 40 00 90 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 c7 c0 0f 00 00 00 0f 05 <0f> 1f 80 00 00 00 00 48 81 ec 48 01 00 00 49 89 d0 64 48 8b 04 25 RSP: 002b:00007f216ab13b40 EFLAGS: 00000246 ORIG_RAX: 000000000000000f RAX: ffffffffffffffda RBX: 00007f2169f35f88 RCX: 00007f2169d19959 RDX: 00007f216ab13b40 RSI: 00007f216ab13c70 RDI: 0000000000000011 RBP: 00007f2169f35f80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f2169f35f8c R13: 0000000000000000 R14: 00007ffc279b31b0 R15: 00007ffc279b3298