syzbot


INFO: task hung in grab_super

Status: upstream: reported on 2024/04/06 01:06
Reported-by: syzbot+a6b2cae9bca1698dd825@syzkaller.appspotmail.com
First crash: 80d, last: 80d
Similar bugs (9)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-414 INFO: task hung in grab_super 4 2064d 1902d 0/1 auto-closed as invalid on 2019/04/28 15:34
linux-4.14 INFO: task hung in grab_super C error 241 577d 1893d 0/1 upstream: reported C repro on 2019/04/19 12:37
android-414 INFO: task hung in grab_super (2) 2 1803d 1825d 0/1 auto-closed as invalid on 2019/11/15 12:55
android-49 INFO: task hung in grab_super 1 2142d 2142d 0/3 auto-closed as invalid on 2019/02/22 13:19
linux-5.15 INFO: task hung in grab_super 1 84d 84d 0/3 upstream: reported on 2024/04/01 06:22
upstream INFO: task hung in grab_super udf C 209 519d 2168d 0/27 closed as dup on 2018/07/18 11:42
linux-4.19 INFO: task hung in grab_super vfs udf C error 249 501d 1894d 0/1 upstream: reported C repro on 2019/04/18 03:33
upstream INFO: task hung in grab_super (2) fs 1 384d 384d 0/27 auto-obsoleted due to no activity on 2023/09/05 02:19
android-49 INFO: task hung in grab_super (2) 1 1770d 1770d 0/3 auto-closed as invalid on 2019/12/19 00:51

Sample crash report:
INFO: task syz-executor.3:13062 blocked for more than 143 seconds.
      Not tainted 6.1.84-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.3  state:D stack:26920 pid:13062 ppid:5401   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x142d/0x4550 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 rwsem_down_write_slowpath+0xea1/0x14b0 kernel/locking/rwsem.c:1189
 grab_super+0x59/0x1a0 fs/super.c:386
 sget_fc+0x1b4/0x630 fs/super.c:613
 get_tree_bdev+0x26b/0x620 fs/super.c:1323
 vfs_get_tree+0x88/0x270 fs/super.c:1562
 do_new_mount+0x2ba/0xb40 fs/namespace.c:3051
 do_mount fs/namespace.c:3394 [inline]
 __do_sys_mount fs/namespace.c:3602 [inline]
 __se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3579
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f50d547de69
RSP: 002b:00007f50d61720c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f50d55abf80 RCX: 00007f50d547de69
RDX: 0000000020000040 RSI: 0000000020000140 RDI: 00000000200000c0
RBP: 00007f50d54ca47a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f50d55abf80 R15: 00007fffa3ff2848
 </TASK>

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
 #0: ffffffff8d12ab50 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:516
1 lock held by rcu_tasks_trace/13:
 #0: ffffffff8d12b350 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:516
1 lock held by khungtaskd/28:
 #0: ffffffff8d12a980 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #0: ffffffff8d12a980 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #0: ffffffff8d12a980 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6494
4 locks held by kworker/u4:3/46:
2 locks held by getty/3302:
 #0: ffff888022a15098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
 #1: ffffc900031262f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a7/0x1db0 drivers/tty/n_tty.c:2188
2 locks held by syz-executor.2/5361:
 #0: ffff888072f2c0e0 (&type->s_umount_key#58){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:362
 #1: ffffffff8d12ff78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline]
 #1: ffffffff8d12ff78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x4f0/0x930 kernel/rcu/tree_exp.h:962
2 locks held by kworker/0:16/7112:
 #0: ffff888012472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #1: ffffc90005e0fd20 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
1 lock held by syz-executor.1/12087:
1 lock held by syz-executor.1/13009:
 #0: ffff888037d380e0 (&type->s_umount_key#56/1){+.+.}-{3:3}, at: alloc_super+0x217/0x930 fs/super.c:228
2 locks held by syz-executor.3/13062:
 #0: ffff888140ca2690 (&bdev->bd_fsfreeze_mutex){+.+.}-{3:3}, at: get_tree_bdev+0x197/0x620 fs/super.c:1313
 #1: ffff888037d380e0 (&type->s_umount_key#58){++++}-{3:3}, at: grab_super+0x59/0x1a0 fs/super.c:386
1 lock held by syz-executor.3/14307:
1 lock held by syz-executor.1/16614:
 #0: ffffffff8d12fe40 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x48/0x5f0 kernel/rcu/tree.c:4018

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

NMI backtrace for cpu 0
CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.1.84-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 nmi_cpu_backtrace+0x4e1/0x560 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x1b0/0x3f0 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+0xf88/0xfd0 kernel/hung_task.c:377
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:307
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 16633 Comm: syz-executor.0 Not tainted 6.1.84-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
RIP: 0010:rcu_read_lock_sched_held+0x8/0x130 kernel/rcu/update.c:120
Code: 00 00 e9 fb f5 22 00 66 2e 0f 1f 84 00 00 00 00 00 90 e9 bb f9 22 00 66 2e 0f 1f 84 00 00 00 00 00 90 55 48 89 e5 41 57 41 56 <41> 54 53 48 83 e4 e0 48 83 ec 60 65 48 8b 04 25 28 00 00 00 48 89
RSP: 0018:ffffc9000612fa08 EFLAGS: 00000002
RAX: 0000000000000001 RBX: ffff88814b32e800 RCX: ffff888041935940
RDX: 1ffffffff1fd3608 RSI: ffffffff8fe9b05c RDI: ffff8880377a5940
RBP: ffffc9000612fa18 R08: ffffffff8fe9b040 R09: ffffffff8fe9b048
R10: ffffffff8fe9b058 R11: ffffffff8fe9b050 R12: 0000000000000000
R13: dffffc0000000000 R14: ffffffff8cff2ac0 R15: ffff8880377a5940
FS:  0000555556ecb480(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6257bc4d58 CR3: 000000002c15e000 CR4: 00000000003526e0
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 task_css_set include/linux/cgroup.h:496 [inline]
 task_dfl_cgroup include/linux/cgroup.h:565 [inline]
 task_psi_group+0x50/0x1a0 kernel/sched/psi.c:889
 psi_task_change+0xd2/0x270 kernel/sched/psi.c:922
 psi_enqueue kernel/sched/stats.h:141 [inline]
 enqueue_task+0x2fd/0x3a0 kernel/sched/core.c:2056
 activate_task kernel/sched/core.c:2088 [inline]
 wake_up_new_task+0x4f5/0xca0 kernel/sched/core.c:4742
 kernel_clone+0x4ed/0x920 kernel/fork.c:2713
 __do_sys_clone3 kernel/fork.c:2981 [inline]
 __se_sys_clone3+0x373/0x410 kernel/fork.c:2965
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f6256ea9c59
Code: ff ff eb d2 e8 f8 62 fd ff 0f 1f 84 00 00 00 00 00 b8 ea ff ff ff 48 85 ff 74 2c 48 85 d2 74 27 49 89 c8 b8 b3 01 00 00 0f 05 <48> 85 c0 7c 18 74 01 c3 31 ed 48 83 e4 f0 4c 89 c7 ff d2 48 89 c7
RSP: 002b:00007ffc89ac0028 EFLAGS: 00000206 ORIG_RAX: 00000000000001b3
RAX: ffffffffffffffda RBX: 00007f6256e52350 RCX: 00007f6256ea9c59
RDX: 00007f6256e52350 RSI: 0000000000000058 RDI: 00007ffc89ac0070
RBP: 00007f6257bc46c0 R08: 00007f6257bc46c0 R09: 00007ffc89ac0157
R10: 0000000000000008 R11: 0000000000000206 R12: ffffffffffffffb0
R13: 000000000000006e R14: 00007ffc89ac0070 R15: 00007ffc89ac0158
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/04/06 01:05 linux-6.1.y 347385861c50 77230c29 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in grab_super
* Struck through repros no longer work on HEAD.