rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4328/1:b..l (detected by 0, t=10503 jiffies, g=7945, q=62) task:kworker/u4:7 state:R running task stack:26528 pid: 4328 ppid: 2 flags:0x00004000 Workqueue: bat_events batadv_nc_worker Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6780 irqentry_exit+0x63/0x70 kernel/entry/common.c:432 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:lock_acquire+0x1f2/0x3f0 kernel/locking/lockdep.c:5627 Code: 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 0f 85 f6 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 66 43 c7 44 3d 09 00 00 43 c6 44 3d 0b RSP: 0018:ffffc9000322faa0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 0000000000000000 RCX: ebe10223dfd24d00 RDX: 0000000000000000 RSI: ffffffff8a0b2460 RDI: ffffffff8a59a700 RBP: ffffc9000322fbc0 R08: dffffc0000000000 R09: fffffbfff1ff3619 R10: fffffbfff1ff3619 R11: 1ffffffff1ff3618 R12: ffffffff8c11c060 R13: 1ffff92000645f60 R14: 0000000000000246 R15: dffffc0000000000 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:312 rcu_read_lock include/linux/rcupdate.h:739 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline] batadv_nc_worker+0xc9/0x5c0 net/batman-adv/network-coding.c:723 process_one_work+0x863/0x1000 kernel/workqueue.c:2310 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 rcu: rcu_preempt kthread starved for 10529 jiffies! g7945 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:27848 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376 schedule+0x11b/0x1e0 kernel/sched/core.c:6459 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914 rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972 rcu_gp_kthread+0x98/0x350 kernel/rcu/tree.c:2145 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 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: 4420 Comm: syz.4.52 Not tainted 5.15.184-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:lockdep_recursion_finish kernel/locking/lockdep.c:436 [inline] RIP: 0010:lock_acquire+0x1a2/0x3f0 kernel/locking/lockdep.c:5625 Code: 74 24 1c 89 da 48 8b 4c 24 28 4c 8b 44 24 30 6a 00 6a 00 ff 75 10 ff 74 24 38 e8 99 03 00 00 48 83 c4 20 48 c7 c7 60 24 0b 8a 89 57 45 08 b8 ff ff ff ff 65 0f c1 05 9c 92 a6 7e 83 f8 01 0f RSP: 0018:ffffc90000dd0c80 EFLAGS: 00000082 RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff815bfd00 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8a0b2460 RBP: ffffc90000dd0d88 R08: dffffc0000000000 R09: fffffbfff1ff361b R10: fffffbfff1ff361b R11: 1ffffffff1ff361a R12: ffff888023552518 R13: 1ffff920001ba19c R14: 0000000000000046 R15: dffffc0000000000 FS: 00007f39d26366c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c2bb75d CR3: 000000002bea1000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa4/0xf0 kernel/locking/spinlock.c:162 __lock_task_sighand+0x12a/0x290 kernel/signal.c:1404 lock_task_sighand include/linux/sched/signal.h:710 [inline] do_send_sig_info kernel/signal.c:1293 [inline] group_send_sig_info+0x1ac/0x220 kernel/signal.c:1442 do_bpf_send_signal+0x7b/0x150 kernel/trace/bpf_trace.c:779 irq_work_single kernel/irq_work.c:155 [inline] irq_work_run_list+0x1bb/0x330 kernel/irq_work.c:177 irq_work_run+0x63/0xe0 kernel/irq_work.c:186 __sysvec_irq_work+0x98/0x240 arch/x86/kernel/irq_work.c:22 instr_sysvec_irq_work arch/x86/kernel/irq_work.c:17 [inline] sysvec_irq_work+0x98/0xc0 arch/x86/kernel/irq_work.c:17 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713 RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:27 [inline] RIP: 0010:static_key_false include/linux/jump_label.h:212 [inline] RIP: 0010:native_write_msr arch/x86/include/asm/msr.h:156 [inline] RIP: 0010:wrmsr arch/x86/include/asm/msr.h:263 [inline] RIP: 0010:native_apic_msr_write+0x35/0x50 arch/x86/include/asm/apic.h:208 Code: 74 2a 83 ff 30 74 25 eb 10 81 ff d0 00 00 00 74 1b 81 ff e0 00 00 00 74 13 c1 ef 04 81 c7 00 08 00 00 89 f9 89 f0 31 d2 0f 30 <66> 90 c3 89 f6 31 d2 e9 cf 3d c8 02 66 2e 0f 1f 84 00 00 00 00 00 RSP: 0018:ffffc900032cfcb0 EFLAGS: 00000246 RAX: 00000000000000f6 RBX: ffffffff8bbafa10 RCX: 000000000000083f RDX: 0000000000000000 RSI: 00000000000000f6 RDI: 000000000000083f RBP: 0000000000000000 R08: dffffc0000000000 R09: ffffed10172267a7 R10: ffffed10172267a7 R11: 1ffff110172267a6 R12: ffff8880b9133b01 R13: dffffc0000000000 R14: dffffc0000000000 R15: 0000000000000020 arch_irq_work_raise+0x82/0xd0 arch/x86/kernel/irq_work.c:31 irq_work_queue+0x95/0x140 kernel/irq_work.c:75 bpf_send_signal_common+0x2b2/0x420 kernel/trace/bpf_trace.c:820 ____bpf_send_signal kernel/trace/bpf_trace.c:829 [inline] bpf_send_signal+0x15/0x20 kernel/trace/bpf_trace.c:827 bpf_prog_7ba5217f62dcd359+0x38/0xf28 bpf_dispatcher_nop_func include/linux/bpf.h:790 [inline] __bpf_prog_run include/linux/filter.h:628 [inline] bpf_prog_run include/linux/filter.h:635 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:1878 [inline] bpf_trace_run2+0x15b/0x2d0 kernel/trace/bpf_trace.c:1915 __bpf_trace_sys_enter+0x60/0x70 include/trace/events/syscalls.h:18 trace_sys_enter+0x65/0x80 include/trace/events/syscalls.h:18 syscall_trace_enter+0x115/0x180 kernel/entry/common.c:77 do_syscall_64+0x24/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f39d476ab39 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:00007f39d2635b40 EFLAGS: 00000246 ORIG_RAX: 000000000000000f RAX: ffffffffffffffda RBX: 00007f39d49f5fa8 RCX: 00007f39d476ab39 RDX: 00007f39d2635b40 RSI: 00007f39d2635c70 RDI: 0000000000000011 RBP: 00007f39d49f5fa0 R08: 0027c191472df9d2 R09: 0000000000000000 R10: 0000200000000000 R11: 0000000000000246 R12: 00007f39d49f5fac R13: 0000000000000000 R14: 00007ffcb5afe200 R15: 00007ffcb5afe2e8