rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P2572/1:b..l P14441/1:b..l rcu: (detected by 0, t=10502 jiffies, g=156277, q=582 ncpus=2) task:syz-executor state:R running task stack:26368 pid:14441 tgid:14441 ppid:5206 flags:0x00004000 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:__nr_to_section include/linux/mmzone.h:1862 [inline] RIP: 0010:__pfn_to_section include/linux/mmzone.h:1970 [inline] RIP: 0010:lookup_page_ext mm/page_ext.c:252 [inline] RIP: 0010:page_ext_get+0xe3/0x310 mm/page_ext.c:536 Code: 3d 00 13 4d 85 e4 0f 84 8a 01 00 00 e8 b6 c1 98 ff 4f 8d 24 ec 48 b8 00 00 00 00 00 fc ff df 4c 89 e2 48 c1 ea 03 80 3c 02 00 <0f> 85 05 02 00 00 4d 8b 24 24 4d 85 e4 0f 84 59 01 00 00 e8 85 c1 RSP: 0018:ffffc90003d7f788 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: 0000000000053ed6 RCX: ffffffff81f1c4a4 RDX: 1ffff11047ffde00 RSI: ffffffff81f1c4ea RDI: 0000000000000007 RBP: 000000000000000a R08: 0000000000000007 R09: 000000000007ffff R10: 000000000000000a R11: 0000000000000000 R12: ffff88823ffef000 R13: 0000000000000000 R14: 00000000018601e1 R15: dffffc0000000000 __set_page_owner+0x96/0x560 mm/page_owner.c:322 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1493 prep_new_page mm/page_alloc.c:1501 [inline] get_page_from_freelist+0x1351/0x2e50 mm/page_alloc.c:3438 __alloc_pages_noprof+0x22b/0x2460 mm/page_alloc.c:4696 alloc_pages_mpol_noprof+0x275/0x610 mm/mempolicy.c:2263 vm_area_alloc_pages mm/vmalloc.c:3584 [inline] __vmalloc_area_node mm/vmalloc.c:3660 [inline] __vmalloc_node_range_noprof+0xa6a/0x1520 mm/vmalloc.c:3841 vmalloc_user_noprof+0x6b/0x90 mm/vmalloc.c:3995 kcov_ioctl+0x4f/0x730 kernel/kcov.c:706 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl fs/ioctl.c:893 [inline] __x64_sys_ioctl+0x193/0x220 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fdeda775b1b RSP: 002b:00007ffc89d27050 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000040000 RCX: 00007fdeda775b1b RDX: 0000000000040000 RSI: ffffffff80086301 RDI: 00000000000000e0 RBP: 00007fdeda9066b8 R08: 00000000000000da R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000009 task:kworker/u8:10 state:R running task stack:23536 pid:2572 tgid:2572 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:lock_acquire+0x1f2/0x560 kernel/locking/lockdep.c:5727 Code: c1 05 6a 1f 9a 7e 83 f8 01 0f 85 ea 02 00 00 9c 58 f6 c4 02 0f 85 d5 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:ffffc90009e47aa0 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 1ffff920013c8f56 RCX: 0000000000000001 RDX: 0000000000000001 RSI: ffffffff8b4cc880 RDI: ffffffff8bb08c00 RBP: 0000000000000200 R08: 0000000000000000 R09: fffffbfff28c4ad8 R10: ffffffff946256c7 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff8ddb5220 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:326 [inline] rcu_read_lock include/linux/rcupdate.h:838 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0x16e/0x10f0 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+0x6c8/0xf20 kernel/workqueue.c:3390 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 10457 jiffies! g156277 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:27584 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 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline] NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:106 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt+0x1a/0x20 drivers/acpi/processor_idle.c:111