syzbot


INFO: task hung in deactivate_super

Status: auto-obsoleted due to no activity on 2023/11/29 20:11
Reported-by: syzbot+906f296f4af9381c2650@syzkaller.appspotmail.com
First crash: 327d, last: 239d
Similar bugs (7)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-49 INFO: task hung in deactivate_super 3 2104d 2121d 0/3 auto-closed as invalid on 2019/02/22 12:34
linux-6.1 INFO: task hung in deactivate_super 4 242d 291d 0/3 auto-obsoleted due to no activity on 2023/11/26 12:17
linux-4.14 INFO: task hung in deactivate_super 1 1814d 1814d 0/1 auto-closed as invalid on 2019/10/25 08:42
upstream INFO: task hung in deactivate_super exfat 36 1925d 2028d 0/26 closed as dup on 2018/10/27 13:17
upstream INFO: task hung in deactivate_super (2) reiserfs C inconclusive done 121 44d 383d 26/26 fixed on 2024/04/08 19:23
linux-6.1 INFO: task hung in deactivate_super (2) 1 62d 62d 0/3 upstream: reported on 2024/02/14 05:27
linux-4.19 INFO: task hung in deactivate_super 4 416d 517d 0/1 upstream: reported on 2022/11/16 10:48

Sample crash report:
INFO: task syz-executor.5:3523 blocked for more than 143 seconds.
      Not tainted 5.15.127-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.5  state:D stack:20344 pid: 3523 ppid:     1 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5026 [inline]
 __schedule+0x12c4/0x4590 kernel/sched/core.c:6372
 schedule+0x11b/0x1f0 kernel/sched/core.c:6455
 rwsem_down_write_slowpath+0xebb/0x15c0 kernel/locking/rwsem.c:1157
 __down_write_common kernel/locking/rwsem.c:1284 [inline]
 __down_write kernel/locking/rwsem.c:1293 [inline]
 down_write+0x164/0x170 kernel/locking/rwsem.c:1542
 deactivate_super+0xa9/0xe0 fs/super.c:365
 cleanup_mnt+0x44e/0x500 fs/namespace.c:1143
 task_work_run+0x129/0x1a0 kernel/task_work.c:164
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop+0x106/0x130 kernel/entry/common.c:175
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:208
 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline]
 syscall_exit_to_user_mode+0x5d/0x250 kernel/entry/common.c:301
 do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7fbf9a3dfe17
RSP: 002b:00007ffd5ed9e268 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007fbf9a3dfe17
RDX: 0000000000000000 RSI: 000000000000000a RDI: 00007ffd5ed9e320
RBP: 00007ffd5ed9e320 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffd5ed9f3e0
R13: 00007fbf9a4293b9 R14: 0000000000092765 R15: 0000000000000004
 </TASK>
INFO: task syz-executor.0:10703 blocked for more than 143 seconds.
      Not tainted 5.15.127-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.0  state:D stack:24344 pid:10703 ppid:  3522 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5026 [inline]
 __schedule+0x12c4/0x4590 kernel/sched/core.c:6372
 schedule+0x11b/0x1f0 kernel/sched/core.c:6455
 jfs_flush_journal+0x72b/0xec0 fs/jfs/jfs_logmgr.c:1572
 jfs_sync_fs+0x7c/0xa0 fs/jfs/super.c:689
 dquot_quota_sync+0xd7/0x490 fs/quota/dquot.c:704
 iterate_supers+0x127/0x1e0 fs/super.c:705
 quota_sync_all fs/quota/quota.c:68 [inline]
 __do_sys_quotactl fs/quota/quota.c:936 [inline]
 __se_sys_quotactl+0x347/0x770 fs/quota/quota.c:915
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f24019ccae9
RSP: 002b:00007f23fff4e0c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007f2401aebf80 RCX: 00007f24019ccae9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000100
RBP: 00007f2401a1847a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f2401aebf80 R15: 00007ffd2c6faab8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c91f0a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by getty/3245:
 #0: ffff88814ad71098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc90002bb62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158
1 lock held by syz-executor.5/3523:
 #0: ffff88807e20c0e0 (&type->s_umount_key#88){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:365
1 lock held by syz-executor.0/10703:
 #0: ffff88807e20c0e0 (&type->s_umount_key#88){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:703
1 lock held by syz-executor.2/10754:
 #0: ffff88807e20c0e0 (&type->s_umount_key#88){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:703
1 lock held by syz-executor.1/10790:
 #0: ffff88807e20c0e0 (&type->s_umount_key#88){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:703
1 lock held by syz-executor.0/10821:
 #0: ffff88807e20c0e0 (&type->s_umount_key#88){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:703
1 lock held by syz-executor.0/10837:
 #0: ffff88807e20c0e0 (&type->s_umount_key#88){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:703

=============================================

NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.15.127-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline]
 watchdog+0xe72/0xeb0 kernel/hung_task.c:295
 kthread+0x3f6/0x4f0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
NMI backtrace for cpu 0 skipped: idling at acpi_safe_halt drivers/acpi/processor_idle.c:109 [inline]
NMI backtrace for cpu 0 skipped: idling at acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:570

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/08/21 20:10 linux-5.15.y f6f7927ac664 6b415825 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in deactivate_super
2023/08/16 20:07 linux-5.15.y f6f7927ac664 39990d51 .config console log report info ci2-linux-5-15-kasan INFO: task hung in deactivate_super
2023/07/19 20:55 linux-5.15.y d54cfc420586 4547cdf9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in deactivate_super
2023/05/25 04:05 linux-5.15.y 1fe619a7d252 4bce1a3e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in deactivate_super
* Struck through repros no longer work on HEAD.