syzbot


INFO: task hung in user_get_super

Status: auto-obsoleted due to no activity on 2023/04/06 01:17
Subsystems: fs
[Documentation on labels]
First crash: 710d, last: 710d
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 601d 608d 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 458 17d 385d 0/28 upstream: reported C repro on 2023/11/19 11:27
linux-5.15 INFO: task hung in user_get_super 6 418d 596d 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 253d 253d 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) 25 35d 384d 0/3 upstream: reported on 2023/11/20 11:19
linux-5.15 INFO: task hung in user_get_super (3) 9 96d 141d 0/3 upstream: reported on 2024/07/19 22:48

Sample crash report:
INFO: task syz-executor.2:13117 blocked for more than 143 seconds.
      Not tainted 6.2.0-rc1-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.2  state:D stack:24488 pid:13117 ppid:5122   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x995/0xe20 kernel/sched/core.c:6555
 schedule+0xcb/0x190 kernel/sched/core.c:6631
 rwsem_down_read_slowpath+0x5f9/0x930 kernel/locking/rwsem.c:1095
 __down_read_common+0x54/0x2a0 kernel/locking/rwsem.c:1260
 user_get_super+0x13e/0x270 fs/super.c:856
 quotactl_block fs/quota/quota.c:890 [inline]
 __do_sys_quotactl fs/quota/quota.c:954 [inline]
 __se_sys_quotactl+0x44d/0x6f0 fs/quota/quota.c:916
 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+0x63/0xcd
RIP: 0033:0x7f65fb08c0a9
RSP: 002b:00007f65fbe91168 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007f65fb1abf80 RCX: 00007f65fb08c0a9
RDX: 0000000000000000 RSI: 0000000020000040 RDI: 0000000000000000
RBP: 00007f65fb0e7ae9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffddcff8a3f R14: 00007f65fbe91300 R15: 0000000000022000
 </TASK>

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
 #0: ffffffff8d326e90 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x30/0xd00 kernel/rcu/tasks.h:507
1 lock held by rcu_tasks_trace/13:
 #0: ffffffff8d327690 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x30/0xd00 kernel/rcu/tasks.h:507
1 lock held by khungtaskd/28:
 #0: ffffffff8d326cc0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
1 lock held by klogd/4423:
 #0: ffff8880b993a1d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x25/0x110 kernel/sched/core.c:537
2 locks held by getty/4754:
 #0: ffff88814bc18098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
 #1: ffffc900015b02f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x53b/0x1650 drivers/tty/n_tty.c:2177
6 locks held by syz-executor.5/11643:
1 lock held by syz-executor.2/13117:
 #0: ffff88807de1a0e0 (&type->s_umount_key#99){++++}-{3:3}, at: user_get_super+0x13e/0x270 fs/super.c:856
1 lock held by syz-executor.2/13188:
 #0: ffff88807de1a0e0 (&type->s_umount_key#99){++++}-{3:3}, at: user_get_super+0x13e/0x270 fs/super.c:856
1 lock held by syz-executor.2/13247:
 #0: ffff88807de1a0e0 (&type->s_umount_key#99){++++}-{3:3}, at: user_get_super+0x13e/0x270 fs/super.c:856

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

NMI backtrace for cpu 1
CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.2.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1b1/0x290 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x46f/0x4f0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x1ba/0x420 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
 watchdog+0xcd5/0xd20 kernel/hung_task.c:377
 kthread+0x266/0x300 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 15 Comm: ksoftirqd/0 Not tainted 6.2.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
RIP: 0010:select_task_rq_fair+0x3dd/0x730
Code: 44 24 28 eb 15 0f 1f 84 00 00 00 00 00 48 8b 6d 00 48 85 ed 0f 84 47 01 00 00 4c 8d 6d 3c 4d 89 ef 49 c1 ef 03 43 0f b6 04 27 <84> c0 0f 85 cd 00 00 00 41 8b 45 00 85 db 0f 84 7f 00 00 00 a8 10
RSP: 0018:ffffc90000147848 EFLAGS: 00000803
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: ffffffff8aedcc40 RDI: ffffffff8b4bc160
RBP: ffff888012ba8000 R08: dffffc0000000000 R09: fffffbfff20fc231
R10: fffffbfff20fc231 R11: 1ffffffff20fc230 R12: dffffc0000000000
R13: ffff888012ba803c R14: 0000000000000000 R15: 1ffff11002575007
FS:  0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005654b4641120 CR3: 000000000d08e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 select_task_rq kernel/sched/core.c:3504 [inline]
 try_to_wake_up+0x5dd/0xab0 kernel/sched/core.c:4201
 autoremove_wake_function kernel/sched/wait.c:419 [inline]
 wake_bit_function+0xf7/0x240 kernel/sched/wait_bit.c:31
 __wake_up_common+0x2aa/0x4e0 kernel/sched/wait.c:107
 __wake_up_common_lock kernel/sched/wait.c:138 [inline]
 __wake_up kernel/sched/wait.c:160 [inline]
 __wake_up_bit kernel/sched/wait_bit.c:126 [inline]
 wake_up_bit+0x1fa/0x2d0 kernel/sched/wait_bit.c:149
 unlock_buffer fs/buffer.c:77 [inline]
 end_buffer_write_sync+0xff/0x180 fs/buffer.c:173
 end_bio_bh_io_sync+0xb1/0x110 fs/buffer.c:2655
 req_bio_endio block/blk-mq.c:794 [inline]
 blk_update_request+0x51c/0x1040 block/blk-mq.c:926
 blk_mq_end_request+0x39/0x70 block/blk-mq.c:1053
 blk_complete_reqs block/blk-mq.c:1131 [inline]
 blk_done_softirq+0x119/0x160 block/blk-mq.c:1136
 __do_softirq+0x277/0x738 kernel/softirq.c:571
 run_ksoftirqd+0xa2/0x100 kernel/softirq.c:934
 smpboot_thread_fn+0x533/0xa10 kernel/smpboot.c:164
 kthread+0x266/0x300 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2022/12/29 01:00 upstream 1b929c02afd3 44712fbc .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in user_get_super
* Struck through repros no longer work on HEAD.