syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P16/4:b..l P7723/1:b..l P29/4:b..l
rcu: 	(detected by 1, t=10502 jiffies, g=21377, q=225 ncpus=2)
task:ktimers/1       state:R  running task     stack:23104 pid:29    tgid:29    ppid:2      task_flags:0x4208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x145f/0x5070 kernel/sched/core.c:6863
 __schedule_loop kernel/sched/core.c:6945 [inline]
 schedule_rtlock+0x30/0x70 kernel/sched/core.c:7024
 rtlock_slowlock_locked+0x3819/0x4010 kernel/locking/rtmutex.c:1868
 rtlock_slowlock kernel/locking/rtmutex.c:1895 [inline]
 rtlock_lock kernel/locking/spinlock_rt.c:43 [inline]
 __rt_spin_lock kernel/locking/spinlock_rt.c:49 [inline]
 rt_spin_lock+0x158/0x3e0 kernel/locking/spinlock_rt.c:57
 spin_lock include/linux/spinlock_rt.h:44 [inline]
 kcov_remote_start+0x12d/0x710 kernel/kcov.c:886
 kcov_remote_start_common include/linux/kcov.h:50 [inline]
 ieee80211_rx_list+0x763/0x2fd0 net/mac80211/rx.c:5521
 ieee80211_rx_napi+0x1a8/0x3d0 net/mac80211/rx.c:5562
 ieee80211_rx include/net/mac80211.h:5216 [inline]
 ieee80211_handle_queued_frames+0xe8/0x1e0 net/mac80211/main.c:452
 tasklet_action_common+0x2bf/0x540 kernel/softirq.c:925
 handle_softirqs+0x1df/0x650 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 run_ktimerd+0x69/0x100 kernel/softirq.c:1138
 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
task:syz-executor    state:S stack:21592 pid:7723  tgid:7723  ppid:7707   task_flags:0x400140 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x145f/0x5070 kernel/sched/core.c:6863
 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7190
 irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:unwind_next_frame+0xd34/0x23d0 arch/x86/include/asm/stacktrace.h:-1
Code: 89 dd 49 c1 ed 03 48 b8 00 00 00 00 00 fc ff df 41 80 7c 05 00 00 74 08 48 89 df e8 d6 f6 ad 00 48 89 5c 24 60 4c 89 64 24 18 <49> 8d 5c 24 f8 4d 8b 66 10 48 b8 00 00 00 00 00 fc ff df 48 8b 4c
RSP: 0018:ffffc9001c577198 EFLAGS: 00000246
RAX: dffffc0000000000 RBX: ffffc9001c577278 RCX: ffffffff8ef2409c
RDX: ffffffff8f68677a RSI: 0000000000000002 RDI: ffffffff8b3f5780
RBP: 1ffff920038aee4e R08: 0000000000000001 R09: ffffffff8d5ae940
R10: ffffc9001c5772b8 R11: ffffffff81ab9860 R12: ffffc9001c577b78
R13: 1ffff920038aee4f R14: ffffc9001c577268 R15: ffffc9001c570000
 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:556
 __call_rcu_common kernel/rcu/tree.c:3119 [inline]
 call_rcu+0xee/0x890 kernel/rcu/tree.c:3239
 destroy_inode fs/inode.c:401 [inline]
 evict+0x931/0xae0 fs/inode.c:861
 proc_invalidate_siblings_dcache+0x42c/0x6c0 fs/proc/inode.c:152
 release_task+0x11d4/0x16d0 kernel/exit.c:291
 wait_task_zombie kernel/exit.c:1274 [inline]
 wait_consider_task+0x1944/0x2e10 kernel/exit.c:1501
 do_wait_thread kernel/exit.c:1564 [inline]
 __do_wait+0x156/0x740 kernel/exit.c:1682
 do_wait+0x1e8/0x4f0 kernel/exit.c:1716
 kernel_wait4+0x1af/0x280 kernel/exit.c:1875
 __do_sys_wait4 kernel/exit.c:1903 [inline]
 __se_sys_wait4 kernel/exit.c:1899 [inline]
 __x64_sys_wait4+0x133/0x1e0 kernel/exit.c:1899
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd5cbe35897
RSP: 002b:00007fffb5923920 EFLAGS: 00000293 ORIG_RAX: 000000000000003d
RAX: ffffffffffffffda RBX: 000000000000003a RCX: 00007fd5cbe35897
RDX: 0000000040000001 RSI: 00007fffb592398c RDI: 00000000ffffffff
RBP: 00007fffb592398c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000001388