rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P1088/1:b..l rcu: (detected by 0, t=10503 jiffies, g=12149, q=1095 ncpus=2) task:kworker/u8:5 state:R running task stack:24208 pid:1088 tgid:1088 ppid:2 flags:0x00004000 Workqueue: bat_events batadv_nc_worker Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0x1800/0x4a60 kernel/sched/core.c:6529 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:6851 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x264/0x550 kernel/locking/lockdep.c:5763 Code: 2b 00 74 08 4c 89 f7 e8 0a 02 8b 00 f6 44 24 61 02 0f 85 85 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25 RSP: 0018:ffffc900042a7980 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff92000854f3c RCX: 5c136068470f1900 RDX: dffffc0000000000 RSI: ffffffff8c0ae6e0 RDI: ffffffff8c606a80 RBP: ffffc900042a7ad0 R08: ffffffff93731847 R09: 1ffffffff26e6308 R10: dffffc0000000000 R11: fffffbfff26e6309 R12: 1ffff92000854f38 R13: dffffc0000000000 R14: ffffc900042a79e0 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:326 [inline] rcu_read_lock include/linux/rcupdate.h:838 [inline] batadv_nc_process_nc_paths+0xd6/0x3a0 net/batman-adv/network-coding.c:687 batadv_nc_worker+0x42a/0x610 net/batman-adv/network-coding.c:728 process_one_work kernel/workqueue.c:3231 [inline] process_scheduled_works+0xa2e/0x1830 kernel/workqueue.c:3312 worker_thread+0x86d/0xd40 kernel/workqueue.c:3390 kthread+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/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 10526 jiffies! g12149 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:26448 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0x1800/0x4a60 kernel/sched/core.c:6529 __schedule_loop kernel/sched/core.c:6606 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6621 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2581 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2034 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2236 kthread+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/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: 5804 Comm: syz-executor.3 Not tainted 6.11.0-rc3-syzkaller-00306-gdf6cbc62cc9b #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 RIP: 0010:check_wait_context kernel/locking/lockdep.c:4793 [inline] RIP: 0010:__lock_acquire+0x7f5/0x2040 kernel/locking/lockdep.c:5092 Code: ff 65 8b 05 f9 aa 92 7e b3 02 85 c0 75 21 48 8b 44 24 58 0f b6 04 10 84 c0 0f 85 66 14 00 00 48 8b 44 24 18 83 38 00 0f 94 c3 <00> db 80 c3 02 48 8b 44 24 38 0f b6 04 10 84 c0 0f 85 9c 12 00 00 RSP: 0018:ffffc900042979f0 EFLAGS: 00000046 RAX: ffff88802125e4c4 RBX: 0000000000000001 RCX: 0000000000000003 RDX: dffffc0000000000 RSI: ffff88802125e4e0 RDI: 0000000000000000 RBP: 00000000ffffffff R08: ffffffff93731877 R09: 1ffffffff26e630e R10: dffffc0000000000 R11: fffffbfff26e630f R12: 0000000000000000 R13: ffff88802125e4d8 R14: 1ffff1100424bca0 R15: ffff88802125e500 FS: 00007fc6aaf736c0(0000) GS:ffff8880b9300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc6aaf72f00 CR3: 000000006f708000 CR4: 0000000000350ef0 Call Trace: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759 __might_fault+0xc6/0x120 mm/memory.c:6388 rseq_get_rseq_cs kernel/rseq.c:161 [inline] rseq_ip_fixup kernel/rseq.c:281 [inline] __rseq_handle_notify_resume+0x120/0x14e0 kernel/rseq.c:329 rseq_handle_notify_resume include/linux/rseq.h:38 [inline] rseq_signal_deliver include/linux/rseq.h:47 [inline] setup_rt_frame arch/x86/kernel/signal.c:212 [inline] handle_signal arch/x86/kernel/signal.c:267 [inline] arch_do_signal_or_restart+0x3ab/0x860 arch/x86/kernel/signal.c:312 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc6aa27cae9 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:00007fc6aaf730c8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 00007fc6aa39bf80 RCX: 00007fc6aa27cae9 RDX: 000000002006b000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fc6aa2c847a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fc6aa39bf80 R15: 00007ffdf15374b8 sched: RT throttling activated