syzbot


INFO: task hung in user_get_super (3)

Status: upstream: reported on 2024/07/19 22:48
Reported-by: syzbot+8ac954867f1a93d70299@syzkaller.appspotmail.com
First crash: 82d, last: 37d
Similar bugs (6)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 INFO: task hung in user_get_super 2 542d 549d 0/3 auto-obsoleted due to no activity on 2023/08/15 03:00
upstream INFO: task hung in user_get_super (2) fs C 437 5h19m 326d 0/28 upstream: reported C repro on 2023/11/19 11:27
linux-5.15 INFO: task hung in user_get_super 6 359d 537d 0/3 auto-obsoleted due to no activity on 2024/01/25 03:23
linux-5.15 INFO: task hung in user_get_super (2) 1 193d 193d 0/3 auto-obsoleted due to no activity on 2024/07/08 17:00
linux-6.1 INFO: task hung in user_get_super (2) 24 20d 325d 0/3 upstream: reported on 2023/11/20 11:19
upstream INFO: task hung in user_get_super fs 1 651d 651d 0/28 auto-obsoleted due to no activity on 2023/04/06 01:17

Sample crash report:
INFO: task syz.0.1250:8776 blocked for more than 144 seconds.
      Not tainted 5.15.164-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.1250      state:D stack:26392 pid: 8776 ppid:  8725 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376
 schedule+0x11b/0x1f0 kernel/sched/core.c:6459
 rwsem_down_write_slowpath+0xf0c/0x16a0 kernel/locking/rwsem.c:1165
 user_get_super+0xd3/0x250 fs/super.c:835
 quotactl_block fs/quota/quota.c:889 [inline]
 __do_sys_quotactl fs/quota/quota.c:953 [inline]
 __se_sys_quotactl+0x490/0x770 fs/quota/quota.c:915
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f5b269b29f9
RSP: 002b:00007f5b24e31038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007f5b26b40f80 RCX: 00007f5b269b29f9
RDX: 0000000000000000 RSI: 0000000020000080 RDI: ffffffff80000200
RBP: 00007f5b26a208ee R08: 0000000000000000 R09: 0000000000000000
R10: 0000000020000100 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f5b26b40f80 R15: 00007ffee1e80f68
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c91fb20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by kworker/1:2/1292:
 #0: ffff888011c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283
 #1: ffffc900052dfd20 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285
2 locks held by getty/3323:
 #0: ffff88802464f098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc90002bab2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158
3 locks held by kworker/0:4/3608:
 #0: ffff888011c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283
 #1: ffffc90002f37d20 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285
 #2: ffff8880793e0240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x2cd/0x4120 drivers/net/netdevsim/fib.c:1478
2 locks held by kworker/u4:11/4704:
2 locks held by syz-executor/5246:
 #0: ffff8880242b80e0 (&type->s_umount_key#116){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:365
 #1: ffffffff8ccbbf88 (jfs_log_mutex){+.+.}-{3:3}, at: lmLogClose+0xae/0x530 fs/jfs/jfs_logmgr.c:1452
2 locks held by syz-executor/6663:
 #0: ffff8880737e20e0 (&type->s_umount_key#116){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:365
 #1: ffffffff8ccbbf88 (jfs_log_mutex){+.+.}-{3:3}, at: lmLogClose+0xae/0x530 fs/jfs/jfs_logmgr.c:1452
1 lock held by syz.4.1226/8667:
 #0: ffff8880737e20e0 (&type->s_umount_key#116){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:703
3 locks held by syz-executor/8762:
 #0: ffff88807c2e0ff0 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0x63/0x1070 net/bluetooth/hci_core.c:1737
 #1: ffff88807c2e0078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_do_close+0x431/0x1070 net/bluetooth/hci_core.c:1782
 #2: ffffffff8db79ea8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1522 [inline]
 #2: ffffffff8db79ea8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xb8/0x220 net/bluetooth/hci_conn.c:1622
1 lock held by syz.0.1250/8776:
 #0: ffff8880737e20e0 (&type->s_umount_key#116){++++}-{3:3}, at: user_get_super+0xd3/0x250 fs/super.c:835
1 lock held by syz.3.1286/8929:
 #0: ffff8880737e20e0 (&type->s_umount_key#116){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:703
3 locks held by syz-executor/9587:
 #0: ffff888049538ff0 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0x63/0x1070 net/bluetooth/hci_core.c:1737
 #1: ffff888049538078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_do_close+0x431/0x1070 net/bluetooth/hci_core.c:1782
 #2: ffffffff8db79ea8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1522 [inline]
 #2: ffffffff8db79ea8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xb8/0x220 net/bluetooth/hci_conn.c:1622
4 locks held by syz-executor/10567:
 #0: ffff888059be4ff0 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0x63/0x1070 net/bluetooth/hci_core.c:1737
 #1: ffff888059be4078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_do_close+0x431/0x1070 net/bluetooth/hci_core.c:1782
 #2: ffffffff8db79ea8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1522 [inline]
 #2: ffffffff8db79ea8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xb8/0x220 net/bluetooth/hci_conn.c:1622
 #3: ffffffff8c9240e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
 #3: ffffffff8c9240e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x280/0x740 kernel/rcu/tree_exp.h:845
1 lock held by syz.0.1759/10734:
 #0: ffff8880737e20e0 (&type->s_umount_key#116){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:703
1 lock held by syz.0.1759/10735:
 #0: ffff8880737e20e0 (&type->s_umount_key#116){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:703
3 locks held by syz-executor/10835:
 #0: ffff888043d08ff0 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0x63/0x1070 net/bluetooth/hci_core.c:1737
 #1: ffff888043d08078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_do_close+0x431/0x1070 net/bluetooth/hci_core.c:1782
 #2: ffffffff8db79ea8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1522 [inline]
 #2: ffffffff8db79ea8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xb8/0x220 net/bluetooth/hci_conn.c:1622
3 locks held by syz-executor/10855:
 #0: ffff88805e078ff0 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0x63/0x1070 net/bluetooth/hci_core.c:1737
 #1: ffff88805e078078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_do_close+0x431/0x1070 net/bluetooth/hci_core.c:1782
 #2: ffffffff8db79ea8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1522 [inline]
 #2: ffffffff8db79ea8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xb8/0x220 net/bluetooth/hci_conn.c:1622

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

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.164-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 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:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt drivers/acpi/processor_idle.c:108 [inline]
NMI backtrace for cpu 1 skipped: idling at acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:562

Crashes (9):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/08/08 02:49 linux-5.15.y 7e89efd3ae1c de12cf65 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in user_get_super
2024/07/27 12:12 linux-5.15.y 7e89efd3ae1c 46eb10b7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in user_get_super
2024/07/23 15:02 linux-5.15.y 7c6d66f0266f e50e8da5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in user_get_super
2024/07/20 08:11 linux-5.15.y 7c6d66f0266f b88348e9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in user_get_super
2024/07/19 22:48 linux-5.15.y 7c6d66f0266f 890ce4f3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in user_get_super
2024/09/03 06:39 linux-5.15.y fa93fa65db6e 8045124c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in user_get_super
2024/09/03 06:34 linux-5.15.y fa93fa65db6e 8045124c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in user_get_super
2024/09/03 06:16 linux-5.15.y fa93fa65db6e 8045124c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in user_get_super
2024/07/28 05:41 linux-5.15.y 7e89efd3ae1c 46eb10b7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in user_get_super
* Struck through repros no longer work on HEAD.