rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P8457/1:b..l
rcu: 	(detected by 0, t=10503 jiffies, g=30269, q=919679 ncpus=2)
task:syz.2.643       state:R  running task     stack:25096 pid:8457  tgid:8457  ppid:5879   task_flags:0x40004c flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7288
 irqentry_exit+0x6f/0x90 kernel/entry/common.c:197
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:206 [inline]
RIP: 0010:unwind_next_frame+0x1c6/0x2390 arch/x86/kernel/unwind_orc.c:494
Code: 24 18 74 08 4c 89 ff e8 18 57 b0 00 4d 8b 27 48 83 f3 01 48 c7 c2 c0 40 88 8b 49 29 dc 0f 84 a2 01 00 00 49 81 fc 00 00 00 81 <0f> 92 c0 49 81 fc ac 72 7d 8b 0f 93 c1 08 c1 0f 85 e8 00 00 00 48
RSP: 0018:ffffc9001c69f238 EFLAGS: 00000202
RAX: 1ffff920038d3e6a RBX: 0000000000000001 RCX: a0a67ed70d672e00
RDX: ffffffff8b8840c0 RSI: ffffffff8be33660 RDI: ffffffff8be33620
RBP: dffffc0000000000 R08: 0000000000000000 R09: ffffffff8172c195
R10: ffffc9001c69f358 R11: ffffffff81ac3820 R12: ffffffff81845a29
R13: ffffc9001c69f358 R14: ffffc9001c69f308 R15: ffffc9001c69f350
 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:47
 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:548
 __call_rcu_common kernel/rcu/tree.c:3123 [inline]
 call_rcu+0x157/0x9c0 kernel/rcu/tree.c:3243
 slab_free_hook mm/slub.c:2381 [inline]
 slab_free mm/slub.c:4680 [inline]
 kmem_cache_free+0x309/0x400 mm/slub.c:4782
 anon_vma_free mm/rmap.c:137 [inline]
 __put_anon_vma+0x12b/0x2d0 mm/rmap.c:2764
 put_anon_vma include/linux/rmap.h:117 [inline]
 unlink_anon_vmas+0x503/0x670 mm/rmap.c:444
 free_pgtables+0x72b/0x9c0 mm/memory.c:413
 exit_mmap+0x444/0xb50 mm/mmap.c:1291
 __mmput+0x118/0x420 kernel/fork.c:1130
 exit_mm+0x1da/0x2c0 kernel/exit.c:582
 do_exit+0x648/0x2300 kernel/exit.c:949
 do_group_exit+0x21c/0x2d0 kernel/exit.c:1102
 __do_sys_exit_group kernel/exit.c:1113 [inline]
 __se_sys_exit_group kernel/exit.c:1111 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1111
 x64_sys_call+0x21f7/0x2200 arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2b0678ebe9
RSP: 002b:00007f2b06adf578 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 000000000000000b RCX: 00007f2b0678ebe9
RDX: 00007f2b06746207 RSI: 0000000000000000 RDI: 000000000000000b
RBP: 0000000000000003 R08: 00007f2b06adfa27 R09: 000000000000000b
R10: 00007f2b069b5fa0 R11: 0000000000000246 R12: 00007f2b069b627c
R13: 00007f2b069b6270 R14: 0000000000001c42 R15: 0000000000000003
 </TASK>