rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P18183/1:b..l
rcu: 	(detected by 0, t=10503 jiffies, g=57653, q=446102 ncpus=2)
task:syz.1.3379      state:R  running task     stack:26088 pid:18183 tgid:18182 ppid:17523  task_flags:0x40054c flags:0x00080001
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7256
 irqentry_exit+0x6f/0x90 kernel/entry/common.c:211
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:rcu_read_unlock include/linux/rcupdate.h:895 [inline]
RIP: 0010:class_rcu_destructor include/linux/rcupdate.h:1195 [inline]
RIP: 0010:unwind_next_frame+0x1957/0x2390 arch/x86/kernel/unwind_orc.c:680
Code: c0 0f 85 9b 03 00 00 c6 03 01 4c 8b 7c 24 48 4c 8b 64 24 20 41 0f b6 04 2c 84 c0 0f 85 2d 03 00 00 41 c7 06 00 00 00 00 31 db <e8> f4 a2 d2 09 85 c0 74 3a e8 4b a8 32 00 84 c0 75 31 e8 e2 a2 d2
RSP: 0018:ffffc900046771f8 EFLAGS: 00000206
RAX: ffffc90004678000 RBX: ffffffff90168001 RCX: ffffc900046779f0
RDX: ffffc90004677301 RSI: dffffc0000000000 RDI: ffffc900046772d0
RBP: dffffc0000000000 R08: ffffc900046779d8 R09: 0000000000000000
R10: ffffc90004677318 R11: fffff520008cee65 R12: ffffc900046779e8
R13: ffffc90004670000 R14: ffffc900046772c8 R15: ffffffff81738d25
 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:56
 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:559
 __call_rcu_common kernel/rcu/tree.c:3123 [inline]
 call_rcu+0x157/0x9c0 kernel/rcu/tree.c:3243
 slab_free_hook mm/slub.c:2503 [inline]
 slab_free mm/slub.c:6630 [inline]
 kmem_cache_free+0x4b5/0x690 mm/slub.c:6740
 exit_mmap+0x537/0xb40 mm/mmap.c:1305
 __mmput+0x118/0x430 kernel/fork.c:1133
 exit_mm+0x1da/0x2c0 kernel/exit.c:582
 do_exit+0x648/0x2300 kernel/exit.c:954
 do_group_exit+0x21c/0x2d0 kernel/exit.c:1107
 get_signal+0x1285/0x1340 kernel/signal.c:3034
 arch_do_signal_or_restart+0xa0/0x790 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop+0x72/0x130 kernel/entry/common.c:40
 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
 do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb65fb8efc9
RSP: 002b:00007fb6609c6038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: 0000000000000001 RBX: 00007fb65fde5fa0 RCX: 00007fb65fb8efc9
RDX: 0000000000000001 RSI: 0000200000001b00 RDI: 0000000000000006
RBP: 00007fb65fc11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000002120 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb65fde6038 R14: 00007fb65fde5fa0 R15: 00007fff8a78fdf8
 </TASK>