INFO: task hung in tun_chr

INFO: task hung in tun_chr_close (2)
Status: auto-closed as invalid on 2021/05/17 11:47
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 395d, last: 174d

similar bugs (4):
Kernel	Title	Count	Last	Reported	Patched	Status
linux-4.19	INFO: task hung in tun_chr_close	1	352d	352d	0/1	auto-closed as invalid on 2020/12/09 18:55
upstream	INFO: task hung in tun_chr_close	5	678d	1260d	0/22	closed as dup on 2018/02/16 08:24
android-49	INFO: task hung in tun_chr_close	1	1174d	1174d	0/3	auto-closed as invalid on 2019/02/22 14:33
android-44	INFO: task hung in tun_chr_close	1	1184d	1183d	0/2	auto-closed as invalid on 2019/02/22 15:23

Sample crash report:

INFO: task syz-executor.0:16228 blocked for more than 146 seconds.
      Not tainted 5.11.0-rc6-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.0  state:D stack:27304 pid:16228 ppid:  8448 flags:0x00004006
Call Trace:
 context_switch kernel/sched/core.c:4327 [inline]
 __schedule+0x90c/0x21a0 kernel/sched/core.c:5078
 schedule+0xcf/0x270 kernel/sched/core.c:5157
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:5216
 __mutex_lock_common kernel/locking/mutex.c:1033 [inline]
 __mutex_lock+0x81a/0x1110 kernel/locking/mutex.c:1103
 tun_detach drivers/net/tun.c:676 [inline]
 tun_chr_close+0x3a/0x180 drivers/net/tun.c:3354
 __fput+0x283/0x920 fs/file_table.c:280
 task_work_run+0xdd/0x190 kernel/task_work.c:140
 exit_task_work include/linux/task_work.h:30 [inline]
 do_exit+0xc5c/0x2ae0 kernel/exit.c:825
 do_group_exit+0x125/0x310 kernel/exit.c:922
 get_signal+0x427/0x20f0 kernel/signal.c:2773
 arch_do_signal_or_restart+0x2a8/0x1eb0 arch/x86/kernel/signal.c:811
 handle_signal_work kernel/entry/common.c:147 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
 exit_to_user_mode_prepare+0x148/0x250 kernel/entry/common.c:201
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:302
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x465b09
RSP: 002b:00007fac4732b218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 000000000056bf68 RCX: 0000000000465b09
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000056bf68

Crashes (7):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	VM info	Title
ci-upstream-kasan-gce-root	2021/02/06 01:03	upstream	dd86e7fa07a3	23a562df	.config	log	report	info	INFO: task hung in tun_chr_close
ci-upstream-kasan-gce-root	2021/01/26 17:28	upstream	13391c60da33	55a7d4df	.config	log	report	info	INFO: task hung in tun_chr_close
ci-upstream-kasan-gce-root	2020/12/13 20:22	upstream	6bff9bb8a292	b22a7ec3	.config	log	report	info
ci-upstream-kasan-gce-selinux-root	2020/06/29 15:34	upstream	4e99b32169e8	a2cdad9d	.config	log	report
ci-upstream-kasan-gce-386	2020/07/06 12:34	upstream	7cc2a8ea1048	51095195	.config	log	report
ci-upstream-net-this-kasan-gce	2020/09/27 01:32	net	059432495e20	2d5ea0cb	.config	log	report	info
ci-upstream-net-this-kasan-gce	2020/08/21 20:07	net	f6db90964162	6436ce4b	.config	log	report