rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P13697/1:b..l P1042/1:b..l rcu: (detected by 1, t=10502 jiffies, g=60125, q=154 ncpus=2) task:kworker/u4:7 state:R running task stack:24912 pid:1042 ppid:2 flags:0x00004000 Workqueue: bat_events batadv_nc_worker Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0xee1/0x5a10 kernel/sched/core.c:6695 preempt_schedule_irq+0x52/0x90 kernel/sched/core.c:7007 irqentry_exit+0x35/0x80 kernel/entry/common.c:432 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:lock_acquire+0x1ef/0x510 kernel/locking/lockdep.c:5721 Code: c1 05 05 f9 9a 7e 83 f8 01 0f 85 b0 02 00 00 9c 58 f6 c4 02 0f 85 9b 02 00 00 48 85 ed 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 8b 84 24 RSP: 0018:ffffc90004d97ac8 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 1ffff920009b2f5b RCX: 0000000000000001 RDX: 1ffff11003da1158 RSI: ffffffff8a8c9ea0 RDI: ffffffff8ae90b20 RBP: 0000000000000200 R08: 0000000000000000 R09: fffffbfff233c7d0 R10: ffffffff919e3e87 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff8cba7920 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:303 [inline] rcu_read_lock include/linux/rcupdate.h:749 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0x16e/0x10e0 net/batman-adv/network-coding.c:719 process_one_work+0x884/0x15c0 kernel/workqueue.c:2630 process_scheduled_works kernel/workqueue.c:2703 [inline] worker_thread+0x8b9/0x1290 kernel/workqueue.c:2784 kthread+0x33c/0x440 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:304 task:syz-executor.2 state:R running task stack:28368 pid:13697 ppid:5066 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0xee1/0x5a10 kernel/sched/core.c:6695 preempt_schedule_common+0x45/0xc0 kernel/sched/core.c:6864 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3a/0x40 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] copy_pte_range mm/memory.c:1106 [inline] copy_pmd_range mm/memory.c:1167 [inline] copy_pud_range mm/memory.c:1204 [inline] copy_p4d_range mm/memory.c:1228 [inline] copy_page_range+0x12af/0x3d50 mm/memory.c:1326 dup_mmap+0x13f3/0x1d80 kernel/fork.c:758 dup_mm kernel/fork.c:1686 [inline] copy_mm kernel/fork.c:1735 [inline] copy_process+0x6bff/0x73f0 kernel/fork.c:2501 kernel_clone+0xfd/0x920 kernel/fork.c:2909 __do_sys_clone+0xba/0x100 kernel/fork.c:3052 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fc77467cae9 RSP: 002b:00007fc775447078 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007fc77479c050 RCX: 00007fc77467cae9 RDX: 0000000020000080 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fc7746c847a R08: 0000000000000000 R09: 0000000000000000 R10: 00000000200000c0 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007fc77479c050 R15: 00007ffd9caa97b8 rcu: rcu_preempt kthread starved for 10548 jiffies! g60125 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:27792 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0xee1/0x5a10 kernel/sched/core.c:6695 schedule+0xe7/0x1b0 kernel/sched/core.c:6771 schedule_timeout+0x157/0x2c0 kernel/time/timer.c:2167 rcu_gp_fqs_loop+0x1ec/0xa50 kernel/rcu/tree.c:1613 rcu_gp_kthread+0x249/0x380 kernel/rcu/tree.c:1812 kthread+0x33c/0x440 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:304 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 PID: 0 Comm: swapper/1 Not tainted 6.6.0-rc5-syzkaller-00171-gce583d5fb9d3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023 RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:37 [inline] RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:72 [inline] RIP: 0010:acpi_safe_halt+0x1b/0x20 drivers/acpi/processor_idle.c:113 Code: ed c3 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 65 48 8b 04 25 00 bd 03 00 48 8b 00 a8 08 75 0c 66 90 0f 00 2d 17 33 b5 00 fb f4 c3 0f 1f 00 0f b6 47 08 3c 01 74 0b 3c 02 74 05 8b 7f 04 eb 9f RSP: 0018:ffffc9000038fd58 EFLAGS: 00000246 RAX: 0000000000004000 RBX: 0000000000000001 RCX: ffffffff8a3ee92e RDX: 0000000000000001 RSI: ffff888145a68000 RDI: ffff888145a68064 RBP: ffff888145a68064 R08: 0000000000000001 R09: ffffed1017326dbd R10: ffff8880b9936deb R11: 0000000000000000 R12: ffff8881442d4000 R13: ffffffff8d659040 R14: 0000000000000001 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b30124000 CR3: 000000007e369000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: acpi_idle_enter+0xc5/0x160 drivers/acpi/processor_idle.c:707 cpuidle_enter_state+0x82/0x500 drivers/cpuidle/cpuidle.c:267 cpuidle_enter+0x4e/0xa0 drivers/cpuidle/cpuidle.c:388 cpuidle_idle_call kernel/sched/idle.c:215 [inline] do_idle+0x315/0x3f0 kernel/sched/idle.c:282 cpu_startup_entry+0x50/0x60 kernel/sched/idle.c:380 start_secondary+0x20e/0x2a0 arch/x86/kernel/smpboot.c:326 secondary_startup_64_no_verify+0x166/0x16b