rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P7665/1:b..l rcu: (detected by 1, t=10502 jiffies, g=175345, q=243 ncpus=2) task:kworker/u4:8 state:R running task stack:23040 pid:7665 tgid:7665 ppid:2 flags:0x00004000 Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet Call Trace: context_switch kernel/sched/core.c:5400 [inline] __schedule+0xf12/0x5c00 kernel/sched/core.c:6727 preempt_schedule_irq+0x52/0x90 kernel/sched/core.c:7047 irqentry_exit+0x36/0x80 kernel/entry/common.c:348 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:batadv_iv_ogm_schedule_buff+0xc41/0x14f0 net/batman-adv/bat_iv_ogm.c:843 Code: 85 4f 08 00 00 48 8b 1b 48 81 fb 20 47 db 92 0f 84 dc 02 00 00 e8 3f 37 37 f7 48 8d 7b 78 48 89 f8 48 c1 e8 03 42 80 3c 30 00 <0f> 85 0b 08 00 00 41 80 3f 00 48 8b 6b 78 0f 85 07 08 00 00 49 3b RSP: 0018:ffffc90008fffb88 EFLAGS: 00000246 RAX: 1ffff11005e3e00f RBX: ffff88802f1f0000 RCX: ffffffff8a50edcb RDX: ffff8880907ebb80 RSI: ffffffff8a50eb21 RDI: ffff88802f1f0078 RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000007 R11: ffffffff8acf1fe0 R12: ffff88807f246820 R13: ffff88807f26e000 R14: dffffc0000000000 R15: ffffed100fe4dc0f batadv_iv_ogm_schedule net/batman-adv/bat_iv_ogm.c:868 [inline] batadv_iv_ogm_schedule net/batman-adv/bat_iv_ogm.c:861 [inline] batadv_iv_send_outstanding_bat_ogm_packet+0x31e/0x8c0 net/batman-adv/bat_iv_ogm.c:1712 process_one_work+0x886/0x15d0 kernel/workqueue.c:2633 process_scheduled_works kernel/workqueue.c:2706 [inline] worker_thread+0x8b9/0x1290 kernel/workqueue.c:2787 kthread+0x2c6/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 rcu: rcu_preempt kthread starved for 10526 jiffies! g175345 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:28080 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5400 [inline] __schedule+0xf12/0x5c00 kernel/sched/core.c:6727 __schedule_loop kernel/sched/core.c:6802 [inline] schedule+0xe9/0x270 kernel/sched/core.c:6817 schedule_timeout+0x137/0x290 kernel/time/timer.c:2183 rcu_gp_fqs_loop+0x1ec/0xb10 kernel/rcu/tree.c:1631 rcu_gp_kthread+0x24b/0x380 kernel/rcu/tree.c:1830 kthread+0x2c6/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 12067 Comm: syz-executor.1 Not tainted 6.8.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 RIP: 0010:preempt_count_sub+0x50/0x160 kernel/sched/core.c:5889 Code: b6 14 11 38 d0 7c 08 84 d2 0f 85 d3 00 00 00 8b 0d a5 a8 48 11 85 c9 75 1b 65 8b 05 82 34 a9 7e 89 c2 81 e2 ff ff ff 7f 39 da <7c> 13 81 fb fe 00 00 00 76 69 f7 db 65 01 1d 65 34 a9 7e 5b c3 90 RSP: 0018:ffffc90000007978 EFLAGS: 00000002 RAX: 0000000080010003 RBX: 0000000000000001 RCX: 0000000000000000 RDX: 0000000000010003 RSI: ffffffff813a574a RDI: 0000000000000001 RBP: ffffc90000007df0 R08: 0000000000000006 R09: ffffc90000007d90 R10: ffffc90000007df0 R11: 0000000000000002 R12: ffffc90000000000 R13: ffffc90000008000 R14: ffffc90000007df8 R15: ffffc90000007d90 FS: 00007f19c57366c0(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b31031000 CR3: 000000008e2f0000 CR4: 0000000000350ef0 Call Trace: unwind_next_frame+0x1244/0x2390 arch/x86/kernel/unwind_orc.c:672 arch_stack_walk+0xfa/0x170 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x96/0xd0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x50 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:314 [inline] __kasan_slab_alloc+0x81/0x90 mm/kasan/common.c:340 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slub.c:3813 [inline] slab_alloc_node mm/slub.c:3860 [inline] kmem_cache_alloc+0x136/0x320 mm/slub.c:3867 __sigqueue_alloc+0x244/0x6b0 kernel/signal.c:427 __send_signal_locked+0x138/0x11b0 kernel/signal.c:1118 do_send_sig_info kernel/signal.c:1300 [inline] group_send_sig_info+0x2a2/0x300 kernel/signal.c:1451 do_bpf_send_signal+0x9a/0x1d0 kernel/trace/bpf_trace.c:838 irq_work_single+0x1b5/0x260 kernel/irq_work.c:221 irq_work_run_list+0x92/0xc0 kernel/irq_work.c:252 irq_work_run+0x58/0xd0 kernel/irq_work.c:261 __sysvec_irq_work+0x82/0x3a0 arch/x86/kernel/irq_work.c:22 sysvec_irq_work+0x90/0xb0 arch/x86/kernel/irq_work.c:17 asm_sysvec_irq_work+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:202 Code: 90 f3 0f 1e fa 53 48 8b 74 24 08 48 89 fb 48 83 c7 18 e8 fa d6 d6 f6 48 89 df e8 f2 4e d7 f6 e8 dd 64 fd f6 fb bf 01 00 00 00 f2 ee c8 f6 65 8b 05 b3 23 72 75 85 c0 74 02 5b c3 e8 20 e2 6e RSP: 0018:ffffc9000b897cf8 EFLAGS: 00000202 RAX: 0000000002b43e9b RBX: ffff888028a0a500 RCX: 1ffffffff1e75691 RDX: 0000000000000000 RSI: ffffffff8accade0 RDI: 0000000000000001 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff8f3ae717 R11: 0000000000000001 R12: ffff888028a0a998 R13: 0000000000000021 R14: ffff888028a0a900 R15: 1ffff92001712fae spin_unlock_irq include/linux/spinlock.h:401 [inline] get_signal+0x1899/0x2790 kernel/signal.c:2896 arch_do_signal_or_restart+0x90/0x7f0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:105 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:201 [inline] syscall_exit_to_user_mode+0x156/0x2b0 kernel/entry/common.c:212 do_syscall_64+0xe0/0x250 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x63/0x6b RIP: 0033:0x7f19c4a7cda9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f19c57360c8 EFLAGS: 00000246 RAX: 0000000000000006 RBX: 00007f19c4bac050 RCX: 00007f19c4a7cda9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000040 RBP: 00007f19c4ac947a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007f19c4bac050 R15: 00007ffda1551718