rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P7944/1:b..l rcu: (detected by 0, t=10502 jiffies, g=73397, q=1824 ncpus=2) task:udevd state:R running task stack:24160 pid:7944 tgid:7944 ppid:5192 task_flags:0x40014c flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x1585/0x5340 kernel/sched/core.c:6907 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7234 irqentry_exit+0x599/0x620 kernel/entry/common.c:239 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_acquire+0x20b/0x2e0 kernel/locking/lockdep.c:5872 Code: e9 30 ff ff ff e8 f5 23 17 0a f7 c3 00 02 00 00 0f 84 38 ff ff ff 65 48 8b 05 71 71 9f 11 48 3b 44 24 30 75 33 fb 48 83 c4 38 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 56 0a 1a 0a cc 48 8d 3d 6e 0d 95 RSP: 0018:ffffc9000c8a72d8 EFLAGS: 00000286 RAX: 6d1c6ae69dc13900 RBX: 0000000000000246 RCX: 0000000000000046 RDX: 00000000a8a5d556 RSI: ffffffff8e2832c1 RDI: ffffffff8c29bf80 RBP: 0000000000000000 R08: ffffffff8176da45 R09: ffffffff8e9602e0 R10: ffffc9000c8a7438 R11: ffffffff81b11580 R12: 0000000000000002 R13: ffffffff8e9602e0 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:312 [inline] rcu_read_lock include/linux/rcupdate.h:850 [inline] class_rcu_constructor include/linux/rcupdate.h:1193 [inline] unwind_next_frame+0xc2/0x23c0 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4501 [inline] slab_alloc_node mm/slub.c:4830 [inline] kmem_cache_alloc_noprof+0x2bc/0x650 mm/slub.c:4837 kmem_alloc_batch lib/debugobjects.c:371 [inline] fill_pool+0x156/0x590 lib/debugobjects.c:420 debug_objects_fill_pool lib/debugobjects.c:742 [inline] debug_object_activate+0x4a3/0x580 lib/debugobjects.c:831 debug_rcu_head_queue kernel/rcu/rcu.h:236 [inline] __call_rcu_common kernel/rcu/tree.c:3116 [inline] call_rcu+0x43/0x890 kernel/rcu/tree.c:3251 slab_free_hook mm/slub.c:2651 [inline] slab_free mm/slub.c:6124 [inline] kmem_cache_free+0x439/0x630 mm/slub.c:6254 tear_down_vmas+0x312/0x520 mm/mmap.c:1264 exit_mmap+0x4b6/0xa10 mm/mmap.c:1322 __mmput+0x118/0x430 kernel/fork.c:1174 exit_mm+0x168/0x220 kernel/exit.c:581 do_exit+0x62e/0x2320 kernel/exit.c:959 do_group_exit+0x21b/0x2d0 kernel/exit.c:1112 __do_sys_exit_group kernel/exit.c:1123 [inline] __se_sys_exit_group kernel/exit.c:1121 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1121 x64_sys_call+0x221a/0x2240 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff2ecaf16c5 RSP: 002b:00007ffd1209dd38 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 000056003a646ff0 RCX: 00007ff2ecaf16c5 RDX: 00000000000000e7 RSI: fffffffffffffe68 RDI: 0000000000000000 RBP: 000056003a646910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd1209dd80 R14: 0000000000000000 R15: 0000000000000000