syzbot

INFO: task syz-executor:288 blocked for more than 122 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D
 stack:0     pid:288   tgid:288   ppid:1      flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:6016 [inline]
 __schedule+0x1399/0x1fa0 kernel/sched/core.c:7870
 __schedule_loop kernel/sched/core.c:7951 [inline]
 schedule+0xc5/0x240 kernel/sched/core.c:7966
 synchronize_rcu_expedited+0x6eb/0x970 kernel/rcu/tree_exp.h:994
 namespace_unlock+0x248/0x430 fs/namespace.c:1710
 do_umount fs/namespace.c:1937 [inline]
 path_umount+0xecd/0xf50 fs/namespace.c:2020
 ksys_umount fs/namespace.c:2043 [inline]
 __do_sys_umount fs/namespace.c:2048 [inline]
 __se_sys_umount fs/namespace.c:2046 [inline]
 __x64_sys_umount+0x12e/0x180 fs/namespace.c:2046
 x64_sys_call+0x2ab8/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:167
 do_syscall_x64 arch/x86/entry/common.c:47 [inline]
 do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f4675f9d9d7
RSP: 002b:00007ffd5912b428 EFLAGS: 00000246
 ORIG_RAX: 00000000000000a6
RAX: ffffffffffffffda RBX: 00007f4676032050 RCX: 00007f4675f9d9d7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd5912b4e0
RBP: 00007ffd5912b4e0 R08: 00007ffd5912c4e0 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd5912c570
R13: 00007f4676032050 R14: 000000000001b720 R15: 00007ffd5912c5b0
 </TASK>
INFO: task syz-executor:291 blocked for more than 123 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:S stack:0     pid:291   tgid:291   ppid:1      flags:0x00004002