rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5004/1:b..l P6928/1:b..l (detected by 0, t=10502 jiffies, g=182149, q=65 ncpus=2) task:syz-executor state:R running task stack:22144 pid:6928 ppid:6904 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6873 irqentry_exit+0x63/0x70 kernel/entry/common.c:439 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:lock_acquire+0x20f/0x490 kernel/locking/lockdep.c:5666 Code: 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 0f 85 f5 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 66 43 c7 44 3d 09 00 00 43 c6 44 3d 0b RSP: 0018:ffffc90003a67200 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 0000000000000000 RCX: cc0f94acc5b79900 RDX: 0000000000000000 RSI: ffffffff8a8c1700 RDI: ffffffff8adef3a0 RBP: ffffc90003a67310 R08: dffffc0000000000 R09: fffffbfff215c449 R10: fffffbfff215c449 R11: 1ffffffff215c448 R12: 0000000000000001 R13: 1ffff9200074ce4c R14: 0000000000000246 R15: dffffc0000000000 rcu_lock_acquire include/linux/rcupdate.h:350 [inline] rcu_read_lock include/linux/rcupdate.h:791 [inline] get_obj_cgroup_from_current mm/memcontrol.c:3019 [inline] __memcg_kmem_charge_page+0x104/0x380 mm/memcontrol.c:3123 __alloc_pages+0x215/0x4e0 mm/page_alloc.c:5631 __pte_alloc_one include/asm-generic/pgalloc.h:63 [inline] pte_alloc_one+0x80/0x2f0 arch/x86/mm/pgtable.c:33 __pte_alloc+0x21/0x150 mm/memory.c:468 copy_pte_range mm/memory.c:1042 [inline] copy_pmd_range mm/memory.c:1177 [inline] copy_pud_range mm/memory.c:1214 [inline] copy_p4d_range mm/memory.c:1238 [inline] copy_page_range+0x32c2/0x39e0 mm/memory.c:1336 dup_mmap kernel/fork.c:697 [inline] dup_mm kernel/fork.c:1541 [inline] copy_mm+0xde3/0x15c0 kernel/fork.c:1590 copy_process+0x1953/0x4020 kernel/fork.c:2351 kernel_clone+0x225/0x8b0 kernel/fork.c:2757 __do_sys_clone kernel/fork.c:2898 [inline] __se_sys_clone kernel/fork.c:2882 [inline] __x64_sys_clone+0x17c/0x1d0 kernel/fork.c:2882 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f389d185713 RSP: 002b:00007ffd8ca7fe58 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f389d185713 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 0000555558c1a7d0 R11: 0000000000000246 R12: 0000000000000000 R13: 00000000000927c0 R14: 0000000000106604 R15: 00007ffd8ca7fff0 task:kworker/u4:9 state:R running task stack:22320 pid:5004 ppid:2 flags:0x00004000 Workqueue: bat_events batadv_nc_worker Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6873 irqentry_exit+0x63/0x70 kernel/entry/common.c:439 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:cpu_max_bits_warn include/linux/cpumask.h:110 [inline] RIP: 0010:cpumask_check include/linux/cpumask.h:117 [inline] RIP: 0010:cpumask_test_cpu include/linux/cpumask.h:444 [inline] RIP: 0010:cpu_online include/linux/cpumask.h:1030 [inline] RIP: 0010:trace_lock_acquire include/trace/events/lock.h:24 [inline] RIP: 0010:lock_acquire+0xb3/0x490 kernel/locking/lockdep.c:5633 Code: c6 44 3d 0b f3 0f 1f 44 00 00 65 44 8b 35 85 23 9f 7e 48 c7 c0 b0 6e 1f 8e 48 c1 e8 03 42 0f b6 04 38 84 c0 0f 85 87 02 00 00 <44> 3b 35 76 78 bc 0c 0f 83 8c 01 00 00 45 89 f4 41 c1 ee 06 4a 8d RSP: 0018:ffffc90003d17ac0 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000002 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8cb2aca0 RBP: ffffc90003d17bc8 R08: 0000000000000000 R09: 0000000000000000 R10: fffffbfff1c3ed96 R11: 1ffffffff1c3ed95 R12: dffffc0000000000 R13: 1ffff920007a2f64 R14: 0000000000000001 R15: dffffc0000000000 rcu_lock_acquire include/linux/rcupdate.h:350 [inline] rcu_read_lock include/linux/rcupdate.h:791 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0xeb/0x600 net/batman-adv/network-coding.c:719 process_one_work+0x898/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: rcu_preempt kthread starved for 10170 jiffies! g182149 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:26912 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1965 rcu_gp_fqs_loop+0x2f2/0x1310 kernel/rcu/tree.c:1706 rcu_gp_kthread+0x95/0x380 kernel/rcu/tree.c:1905 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 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:51 [inline] NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline] NMI backtrace for cpu 1 skipped: idling at default_idle+0xb/0x10 arch/x86/kernel/process.c:741