rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P2571/1:b..l P21678/1:b..l P4674/1:b..l rcu: (detected by 0, t=10502 jiffies, g=111393, q=231 ncpus=2) task:udevd state:R running task stack:24176 pid:4674 tgid:4674 ppid:1 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0xe37/0x5490 kernel/sched/core.c:6529 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:6708 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] wp_page_copy mm/memory.c:3453 [inline] do_wp_page+0x15fd/0x3430 mm/memory.c:3744 handle_pte_fault mm/memory.c:5554 [inline] __handle_mm_fault+0x2474/0x5650 mm/memory.c:5681 handle_mm_fault+0x498/0xa60 mm/memory.c:5849 do_user_addr_fault+0x60d/0x13f0 arch/x86/mm/fault.c:1338 handle_page_fault arch/x86/mm/fault.c:1481 [inline] exc_page_fault+0x5c/0xc0 arch/x86/mm/fault.c:1539 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x562d15d50e9c RSP: 002b:00007ffcdd4b55f8 EFLAGS: 00010246 RAX: 0000562d299f6138 RBX: 0000562d299f6130 RCX: 000000000000001f RDX: 0000562d299d0e00 RSI: 0000562d299c2010 RDI: 0000562d299f6240 RBP: 0000562d299f6240 R08: 0000000000000000 R09: ae95a2961732cd02 R10: d00103b0a134fd1f R11: 0000000000000007 R12: 0000000000000000 R13: 0000000200000001 R14: 0000000000000000 R15: 0000000000000000 task:udevd state:R running task stack:28464 pid:21678 tgid:21678 ppid:4674 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0xe37/0x5490 kernel/sched/core.c:6529 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:6708 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] wp_page_copy mm/memory.c:3453 [inline] do_wp_page+0x15fd/0x3430 mm/memory.c:3744 handle_pte_fault mm/memory.c:5554 [inline] __handle_mm_fault+0x2474/0x5650 mm/memory.c:5681 handle_mm_fault+0x498/0xa60 mm/memory.c:5849 do_user_addr_fault+0x60d/0x13f0 arch/x86/mm/fault.c:1338 handle_page_fault arch/x86/mm/fault.c:1481 [inline] exc_page_fault+0x5c/0xc0 arch/x86/mm/fault.c:1539 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7f9779cc72a4 RSP: 002b:00007ffcdd4b5380 EFLAGS: 00010206 RAX: 0000000000000003 RBX: 0000000000000003 RCX: 0000562d299eb0e0 RDX: 000056284b4c293c RSI: 0000000000000000 RDI: 0000562d299dccf0 RBP: 0000562d299dcce0 R08: 0000000000000007 R09: ae95a2961732cd02 R10: de738169618cfccf R11: 0000000000000007 R12: 0000000000000000 R13: 0000562d299dcd10 R14: 00007f9779df1aa0 R15: 0000562d299c22c0 task:kworker/u8:11 state:R running task stack:22256 pid:2571 tgid:2571 ppid:2 flags:0x00004000 Workqueue: bat_events batadv_nc_worker Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0xe37/0x5490 kernel/sched/core.c:6529 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:6851 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:lockdep_enabled kernel/locking/lockdep.c:115 [inline] RIP: 0010:lock_release+0xee/0x6f0 kernel/locking/lockdep.c:5772 Code: 00 fc ff df 48 89 ea 48 c1 ea 03 0f b6 14 02 48 89 e8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 03 05 00 00 8b 3d 5a 02 b4 0e <85> ff 0f 84 e5 02 00 00 65 8b 05 3b c1 98 7e 85 c0 0f 85 d6 02 00 RSP: 0018:ffffc90008f17ac8 EFLAGS: 00000246 RAX: 0000000000000003 RBX: 1ffff920011e2f5b RCX: ffffffff8169c9f9 RDX: 0000000000000000 RSI: ffffffff8bb11820 RDI: 0000000000000001 RBP: ffffffff901dcc98 R08: 0000000000000000 R09: fffffbfff203b333 R10: ffffffff901d999f R11: 0000000000000000 R12: ffffffff8ddba6a0 R13: 000000000003d8cc R14: 000000000003d8cc R15: dffffc0000000000 rcu_lock_release include/linux/rcupdate.h:336 [inline] rcu_read_unlock include/linux/rcupdate.h:869 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline] batadv_nc_worker+0x88c/0x1060 net/batman-adv/network-coding.c:719 process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3231 process_scheduled_works kernel/workqueue.c:3312 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3393 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 10568 jiffies! g111393 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:27680 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0xe37/0x5490 kernel/sched/core.c:6529 __schedule_loop kernel/sched/core.c:6606 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6621 schedule_timeout+0x136/0x2a0 kernel/time/timer.c:2581 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2034 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2236 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: 21618 Comm: syz.4.1281 Not tainted 6.11.0-syzkaller-02574-ga430d95c5efa #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 RIP: 0010:hlock_class+0x56/0x130 kernel/locking/lockdep.c:227 Code: 20 66 81 e3 ff 1f 0f b7 db be 08 00 00 00 48 89 d8 48 c1 e8 06 48 8d 3c c5 00 d7 9c 96 e8 12 ba 81 00 48 0f a3 1d 7a f4 33 15 <73> 13 48 69 c3 c8 00 00 00 5b 48 05 20 db 9c 96 c3 cc cc cc cc 48 RSP: 0018:ffffc9000471fa80 EFLAGS: 00000047 RAX: 0000000000000001 RBX: 00000000000000b5 RCX: ffffffff8168e27e RDX: fffffbfff2d39ae3 RSI: 0000000000000008 RDI: ffffffff969cd710 RBP: ffffffff969cf4e8 R08: 0000000000000000 R09: fffffbfff2d39ae2 R10: ffffffff969cd717 R11: 0000000000000000 R12: dffffc0000000000 R13: ffff88803443a930 R14: 0000000000000002 R15: ffff888034439e00 FS: 00007f8028b156c0(0000) GS:ffff8880b8900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000562d299dccf0 CR3: 00000000591b4000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lookup_chain_cache_add kernel/locking/lockdep.c:3780 [inline] validate_chain kernel/locking/lockdep.c:3836 [inline] __lock_acquire+0x1620/0x3cb0 kernel/locking/lockdep.c:5142 lock_acquire kernel/locking/lockdep.c:5759 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5724 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 __lock_task_sighand+0xc2/0x340 kernel/signal.c:1412 lock_task_sighand include/linux/sched/signal.h:746 [inline] do_send_sig_info kernel/signal.c:1300 [inline] group_send_sig_info+0x290/0x300 kernel/signal.c:1451 bpf_send_signal_common+0x2e8/0x3a0 kernel/trace/bpf_trace.c:881 ____bpf_send_signal kernel/trace/bpf_trace.c:886 [inline] bpf_send_signal+0x19/0x30 kernel/trace/bpf_trace.c:884 bpf_prog_7ba5217f62dcd359+0x40/0x44 bpf_dispatcher_nop_func include/linux/bpf.h:1243 [inline] __bpf_prog_run include/linux/filter.h:691 [inline] bpf_prog_run include/linux/filter.h:698 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2406 [inline] bpf_trace_run2+0x231/0x590 kernel/trace/bpf_trace.c:2447 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: 0033:0x7f8027d19879 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:00007f8028b14b40 EFLAGS: 00000246 ORIG_RAX: 000000000000000f RAX: ffffffffffffffda RBX: 00007f8027f35f88 RCX: 00007f8027d19879 RDX: 00007f8028b14b40 RSI: 00007f8028b14c70 RDI: 0000000000000011 RBP: 00007f8027f35f80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f8027f35f8c R13: 0000000000000000 R14: 00007ffe11fd1730 R15: 00007ffe11fd1818