rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P28555/1:b..l
rcu: 	(detected by 0, t=10503 jiffies, g=286405, q=2213 ncpus=2)
task:syz.2.6301      state:R  running task     stack:24008 pid:28555 tgid:28554 ppid:25636  task_flags:0x40054c flags:0x00080001
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:539 [inline]
 irqentry_exit+0x14f/0x8b0 kernel/entry/common.c:164
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:unwind_next_frame+0x19a0/0x2550 arch/x86/kernel/unwind_orc.c:677
Code: b6 04 28 84 c0 0f 85 aa 0a 00 00 49 0f bf 04 24 48 01 c6 4c 89 f7 48 89 da eb 3f 48 8d 5f 02 48 83 c7 03 48 89 d8 48 c1 e8 03 <0f> b6 04 28 84 c0 0f 85 a1 0a 00 00 48 89 f8 48 c1 e8 03 0f b6 04
RSP: 0018:ffffc9000332f0b8 EFLAGS: 00000a02
RAX: 1ffffffff21a1cad RBX: ffffffff90d0e568 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff90d0e569
RBP: dffffc0000000000 R08: ffffc9000332f1e7 R09: 0000000000000000
R10: ffffc9000332f1d8 R11: fffff52000665e3d R12: ffffc9000332f648
R13: 1ffff92000665e33 R14: ffffc9000332f188 R15: 1ffffffff21a1cad
 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
 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
 __call_rcu_common kernel/rcu/tree.c:3131 [inline]
 call_rcu+0xee/0x890 kernel/rcu/tree.c:3251
 slab_free_hook mm/slub.c:2653 [inline]
 slab_free mm/slub.c:6251 [inline]
 kmem_cache_free+0x462/0x650 mm/slub.c:6378
 anon_vma_free mm/rmap.c:137 [inline]
 __put_anon_vma+0x12b/0x2d0 mm/rmap.c:2917
 put_anon_vma mm/internal.h:216 [inline]
 unlink_anon_vmas+0x58b/0x730 mm/rmap.c:536
 free_pgtables+0x836/0xb70 mm/memory.c:414
 exit_mmap+0x490/0x9e0 mm/mmap.c:1312
 __mmput+0x118/0x430 kernel/fork.c:1178
 exit_mm+0x1f6/0x2d0 kernel/exit.c:582
 do_exit+0x6a2/0x22c0 kernel/exit.c:964
 do_group_exit+0x21b/0x2d0 kernel/exit.c:1119
 get_signal+0x1284/0x1330 kernel/signal.c:3037
 arch_do_signal_or_restart+0xbc/0x840 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
 exit_to_user_mode_loop+0xa9/0x680 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
 do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc17699ce59
RSP: 002b:00007fc174bf6028 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: ffffffffffffff8d RBX: 00007fc176c15fa0 RCX: 00007fc17699ce59
RDX: 000000000000001c RSI: 00002000000002c0 RDI: 0000000000000006
RBP: 00007fc176a32d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc176c16038 R14: 00007fc176c15fa0 R15: 00007fc176d3fa48
 </TASK>