rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P8235 P8233 (detected by 1, t=10503 jiffies, g=6553, q=208) syz-executor.1 R running task 24720 8235 8234 0x0000400a Call Trace: context_switch kernel/sched/core.c:3388 [inline] __schedule+0x9a8/0xcc0 kernel/sched/core.c:4081 preempt_schedule_notrace+0xdb/0x120 kernel/sched/core.c:4309 ___preempt_schedule_notrace+0x16/0x27 arch/x86/entry/thunk_64.S:51 rcu_is_watching+0x82/0xa0 kernel/rcu/tree.c:923 rcu_read_unlock include/linux/rcupdate.h:667 [inline] memcg_kmem_get_cache+0x301/0x590 mm/memcontrol.c:2808 slab_pre_alloc_hook mm/slab.h:572 [inline] slab_alloc mm/slab.c:3306 [inline] kmem_cache_alloc+0x86/0x2e0 mm/slab.c:3484 vm_area_dup kernel/fork.c:359 [inline] dup_mmap+0x587/0xe00 kernel/fork.c:544 dup_mm+0x9e/0x340 kernel/fork.c:1360 copy_mm kernel/fork.c:1416 [inline] copy_process+0x1e49/0x5510 kernel/fork.c:2072 _do_fork+0x13e/0x660 kernel/fork.c:2421 __do_sys_clone kernel/fork.c:2576 [inline] __se_sys_clone kernel/fork.c:2557 [inline] __x64_sys_clone+0x20b/0x250 kernel/fork.c:2557 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x458c4a Code: f7 d8 64 89 04 25 d4 02 00 00 64 4c 8b 0c 25 10 00 00 00 31 d2 4d 8d 91 d0 02 00 00 31 f6 bf 11 00 20 01 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 f5 00 00 00 85 c0 41 89 c5 0f 85 fc 00 00 RSP: 002b:00007ffc19d943f0 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007ffc19d943f0 RCX: 0000000000458c4a RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007ffc19d94430 R08: 0000000000000001 R09: 00000000021b4940 R10: 00000000021b4c10 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000000 R15: 00007ffc19d94480 syz-executor.0 R running task 24552 8233 8232 0x8000400a Call Trace: sched_show_task+0x40f/0x560 kernel/sched/core.c:5954 rcu_print_detail_task_stall_rnp kernel/rcu/tree_stall.h:190 [inline] print_other_cpu_stall kernel/rcu/tree_stall.h:398 [inline] check_cpu_stall kernel/rcu/tree_stall.h:538 [inline] rcu_pending kernel/rcu/tree.c:2827 [inline] rcu_sched_clock_irq+0x16b1/0x1ad0 kernel/rcu/tree.c:2271 update_process_times+0x12d/0x180 kernel/time/timer.c:1726 tick_sched_handle kernel/time/tick-sched.c:167 [inline] tick_sched_timer+0x263/0x420 kernel/time/tick-sched.c:1310 __run_hrtimer kernel/time/hrtimer.c:1514 [inline] __hrtimer_run_queues+0x403/0x840 kernel/time/hrtimer.c:1576 hrtimer_interrupt+0x38c/0xda0 kernel/time/hrtimer.c:1638 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1110 [inline] smp_apic_timer_interrupt+0x109/0x280 arch/x86/kernel/apic/apic.c:1135 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829 RIP: 0010:free_thread_stack+0x177/0x590 kernel/fork.c:284 Code: 80 3c 28 00 74 08 48 89 df e8 25 a4 69 00 48 8b 3b be fc ff ff ff e8 28 04 00 00 43 80 3c 2e 00 74 08 4c 89 e7 e8 09 a4 69 00 <49> 8b 1c 24 48 83 c3 08 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 RSP: 0018:ffffc90001e57848 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: ffffffff81487433 RBX: ffff888090d99408 RCX: ffff88809f3ee180 RDX: 0000000000000000 RSI: 00000000fffffffc RDI: ffffea00026290c0 RBP: ffffc90001e57880 R08: 000000000003a768 R09: ffffed10121542bf R10: ffffed10121542bf R11: 0000000000000000 R12: ffff888090d994a0 R13: dffffc0000000000 R14: 1ffff110121b3294 R15: ffff888090aa15e8 release_task_stack kernel/fork.c:440 [inline] put_task_stack+0xa3/0x130 kernel/fork.c:451 finish_task_switch+0x3f1/0x550 kernel/sched/core.c:3256 context_switch kernel/sched/core.c:3388 [inline] __schedule+0x9a8/0xcc0 kernel/sched/core.c:4081 preempt_schedule_notrace+0xdb/0x120 kernel/sched/core.c:4309 ___preempt_schedule_notrace+0x16/0x27 arch/x86/entry/thunk_64.S:51 rcu_is_watching+0x82/0xa0 kernel/rcu/tree.c:923 rcu_read_unlock include/linux/rcupdate.h:667 [inline] memcg_kmem_get_cache+0x301/0x590 mm/memcontrol.c:2808 slab_pre_alloc_hook mm/slab.h:572 [inline] slab_alloc mm/slab.c:3306 [inline] kmem_cache_alloc+0x86/0x2e0 mm/slab.c:3484 anon_vma_alloc mm/rmap.c:83 [inline] anon_vma_fork+0xf7/0x540 mm/rmap.c:361 dup_mmap+0x6b8/0xe00 kernel/fork.c:559 dup_mm+0x9e/0x340 kernel/fork.c:1360 copy_mm kernel/fork.c:1416 [inline] copy_process+0x1e49/0x5510 kernel/fork.c:2072 _do_fork+0x13e/0x660 kernel/fork.c:2421 __do_sys_clone kernel/fork.c:2576 [inline] __se_sys_clone kernel/fork.c:2557 [inline] __x64_sys_clone+0x20b/0x250 kernel/fork.c:2557 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x458c4a Code: f7 d8 64 89 04 25 d4 02 00 00 64 4c 8b 0c 25 10 00 00 00 31 d2 4d 8d 91 d0 02 00 00 31 f6 bf 11 00 20 01 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 f5 00 00 00 85 c0 41 89 c5 0f 85 fc 00 00 RSP: 002b:00007ffe000e6530 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007ffe000e6530 RCX: 0000000000458c4a RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007ffe000e6570 R08: 0000000000000001 R09: 000000000132f940 R10: 000000000132fc10 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000000 R15: 00007ffe000e65c0 rcu: rcu_preempt kthread starved for 10550 jiffies! g6553 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: RCU grace-period kthread stack dump: rcu_preempt R running task 29032 10 2 0x80004000 Call Trace: context_switch kernel/sched/core.c:3385 [inline] __schedule+0x9a0/0xcc0 kernel/sched/core.c:4081 schedule+0x181/0x210 kernel/sched/core.c:4155 schedule_timeout+0x14f/0x240 kernel/time/timer.c:1895 rcu_gp_fqs_loop kernel/rcu/tree.c:1661 [inline] rcu_gp_kthread+0xed8/0x1770 kernel/rcu/tree.c:1821 kthread+0x332/0x350 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352