rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P11968/1:b..l
rcu: 	(detected by 0, t=10503 jiffies, g=79593, q=919550 ncpus=2)
task:syz.2.1749      state:R  running task     stack:26048 pid:11968 tgid:11967 ppid:5638   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5388 [inline]
 __schedule+0x1821/0x5740 kernel/sched/core.c:7189
 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7513
 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline]
 irqentry_exit+0x14f/0x760 kernel/entry/common.c:164
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:110 [inline]
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:238 [inline]
RIP: 0010:unwind_next_frame+0x2b7/0x2550 arch/x86/kernel/unwind_orc.c:510
Code: ff df 0f 84 17 04 00 00 4a 8d 14 ad a4 37 43 90 45 29 e8 4a 8d 1c 82 48 83 c3 fc 49 89 d5 48 39 da 0f 86 1c 02 00 00 49 29 d5 <49> c1 fd 02 4a 8d 04 6d 00 00 00 00 4c 01 e8 48 8d 14 46 48 bd 00
RSP: 0018:ffffc90003b97178 EFLAGS: 00000246
RAX: ffffffff90489924 RBX: ffffffff90489928 RCX: ffffffff9048992c
RDX: ffffffff90489928 RSI: ffffffff90c4120e RDI: ffffffff8c28ae80
RBP: ffffffff9048992c R08: 0000000000000001 R09: ffffffff8e95cd60
R10: ffffc90003b972f8 R11: fffff52000772e61 R12: ffffffff816d8ab2
R13: 0000000000000000 R14: ffffc90003b972a8 R15: ffffffff90489928
 __unwind_start+0x5b8/0x760 arch/x86/kernel/unwind_orc.c:787
 unwind_start arch/x86/include/asm/unwind.h:64 [inline]
 arch_stack_walk+0xe3/0x150 arch/x86/kernel/stacktrace.c:24
 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57
 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556
 slab_free_hook mm/slub.c:2650 [inline]
 slab_free mm/slub.c:6250 [inline]
 kmem_cache_free+0x44f/0x650 mm/slub.c:6377
 tear_down_vmas+0x312/0x520 mm/mmap.c:1262
 exit_mmap+0x4b6/0x9e0 mm/mmap.c:1320
 __mmput+0x118/0x430 kernel/fork.c:1178
 copy_process+0x3086/0x4440 kernel/fork.c:2560
 kernel_clone+0x284/0x8f0 kernel/fork.c:2721
 __do_sys_clone3 kernel/fork.c:3025 [inline]
 __se_sys_clone3+0x33c/0x360 kernel/fork.c:3004
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fba18f9cdd9
RSP: 002b:00007fba19e47ef8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b3
RAX: ffffffffffffffda RBX: 0000000000000058 RCX: 00007fba18f9cdd9
RDX: 00007fba19e47f10 RSI: 0000000000000058 RDI: 00007fba19e47f10
RBP: 00007fba19032d69 R08: 0000000000000000 R09: 0000000000000058
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fba19216038 R14: 00007fba19215fa0 R15: 00007fba1933fa48
 </TASK>