syzbot


INFO: task hung in lookup_one_unlocked

Status: auto-obsoleted due to no activity on 2023/10/27 11:58
Subsystems: overlayfs
[Documentation on labels]
First crash: 760d, last: 760d

Sample crash report:
INFO: task syz-executor.4:23049 blocked for more than 145 seconds.
      Not tainted 6.5.0-rc3-syzkaller-00275-gffabf7c73176 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.4  state:D stack:27712 pid:23049 ppid:19609  flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0xee1/0x59f0 kernel/sched/core.c:6710
 schedule+0xe7/0x1b0 kernel/sched/core.c:6786
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6845
 rwsem_down_read_slowpath+0x625/0xb20 kernel/locking/rwsem.c:1086
 __down_read_common kernel/locking/rwsem.c:1250 [inline]
 __down_read kernel/locking/rwsem.c:1263 [inline]
 down_read+0xf0/0x470 kernel/locking/rwsem.c:1522
 inode_lock_shared include/linux/fs.h:781 [inline]
 lookup_slow fs/namei.c:1706 [inline]
 lookup_one_unlocked+0x12f/0x160 fs/namei.c:2803
 ovl_lookup_positive_unlocked fs/overlayfs/namei.c:213 [inline]
 ovl_lookup_single+0x129/0xd50 fs/overlayfs/namei.c:239
 ovl_lookup_layer+0x3a9/0x4a0 fs/overlayfs/namei.c:326
 ovl_lookup+0x1325/0x22d0 fs/overlayfs/namei.c:1031
 lookup_one_qstr_excl+0x116/0x180 fs/namei.c:1605
 do_rmdir+0x265/0x400 fs/namei.c:4248
 __do_sys_rmdir fs/namei.c:4278 [inline]
 __se_sys_rmdir fs/namei.c:4276 [inline]
 __x64_sys_rmdir+0xc8/0x110 fs/namei.c:4276
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fcab787cb29
RSP: 002b:00007fcab63fe0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000054
RAX: ffffffffffffffda RBX: 00007fcab799c050 RCX: 00007fcab787cb29
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000200002c0
RBP: 00007fcab78c847a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007fcab799c050 R15: 00007fffc569ea98
 </TASK>

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
 #0: ffffffff8c9a2730 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x2c/0xe20 kernel/rcu/tasks.h:522
1 lock held by rcu_tasks_trace/13:
 #0: ffffffff8c9a2430 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x2c/0xe20 kernel/rcu/tasks.h:522
1 lock held by khungtaskd/27:
 #0: 
ffffffff8c9a3340 (
rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x340 kernel/locking/lockdep.c:6615
2 locks held by getty/4771:
 #0: ffff88814af7f098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: ffffc900020482f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfcb/0x1480 drivers/tty/n_tty.c:2187
2 locks held by kworker/1:15/5244:
 #0: ffff88801287a538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:20 [inline]
 #0: ffff88801287a538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: raw_atomic64_set include/linux/atomic/atomic-arch-fallback.h:2608 [inline]
 #0: ffff88801287a538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: raw_atomic_long_set include/linux/atomic/atomic-long.h:79 [inline]
 #0: ffff88801287a538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:3196 [inline]
 #0: ffff88801287a538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:675 [inline]
 #0: ffff88801287a538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:702 [inline]
 #0: ffff88801287a538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x96a/0x16f0 kernel/workqueue.c:2567
 #1: ffffc9000480fd80 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x99e/0x16f0 kernel/workqueue.c:2571
2 locks held by syz-executor.3/19612:
 #0: ffff88807b34e0e0 (&type->s_umount_key#92){++++}-{3:3}, at: deactivate_super+0xd6/0x100 fs/super.c:360
 #1: ffffffff8c9ae7f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:293 [inline]
 #1: ffffffff8c9ae7f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x69e/0x7e0 kernel/rcu/tree_exp.h:992
2 locks held by kworker/u4:19/20281:
 #0: ffff8880b993c418 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:558
 #1: ffff8880b9928848 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x20c/0x900 kernel/sched/psi.c:987
2 locks held by syz-executor.4/23043:
 #0: ffff888039f3c410 (sb_writers#34){.+.+}-{0:0}, at: filename_create+0x10d/0x530 fs/namei.c:3879
 #1: ffff88808049e9a0 (&sb->s_type->i_mutex_key#40/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:806 [inline]
 #1: ffff88808049e9a0 (&sb->s_type->i_mutex_key#40/1){+.+.}-{3:3}, at: filename_create+0x1c2/0x530 fs/namei.c:3886
3 locks held by syz-executor.4/23049:
 #0: ffff888078e04410 (sb_writers#22){.+.+}-{0:0}, at: do_rmdir+0x202/0x400 fs/namei.c:4243
 #1: ffff8880807172b0 (&ovl_i_mutex_dir_key[depth]#2/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:806 [inline]
 #1: ffff8880807172b0 (&ovl_i_mutex_dir_key[depth]#2/1){+.+.}-{3:3}, at: do_rmdir+0x253/0x400 fs/namei.c:4247
 #2: ffff88808049e9a0 (&sb->s_type->i_mutex_key#41){.+.+}-{3:3}, at: inode_lock_shared include/linux/fs.h:781 [inline]
 #2: ffff88808049e9a0 (&sb->s_type->i_mutex_key#41){.+.+}-{3:3}, at: lookup_slow fs/namei.c:1706 [inline]
 #2: ffff88808049e9a0 (&sb->s_type->i_mutex_key#41){.+.+}-{3:3}, at: lookup_one_unlocked+0x12f/0x160 fs/namei.c:2803
5 locks held by kworker/1:9/23934:
 #0: ffff8880152bd938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:20 [inline]
 #0: ffff8880152bd938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: raw_atomic64_set include/linux/atomic/atomic-arch-fallback.h:2608 [inline]
 #0: ffff8880152bd938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: raw_atomic_long_set include/linux/atomic/atomic-long.h:79 [inline]
 #0: ffff8880152bd938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:3196 [inline]
 #0: ffff8880152bd938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:675 [inline]
 #0: ffff8880152bd938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:702 [inline]
 #0: ffff8880152bd938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x96a/0x16f0 kernel/workqueue.c:2567
 #1: ffffc900046ffd80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x99e/0x16f0 kernel/workqueue.c:2571
 #2: ffff888023116190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:958 [inline]
 #2: ffff888023116190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1c8/0x5230 drivers/usb/core/hub.c:5754
 #3: ffff888071e3d190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:958 [inline]
 #3: ffff888071e3d190 (&dev->mutex){....}-{3:3}, at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1003
 #4: ffff88807e49f160 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:958 [inline]
 #4: ffff88807e49f160 (&dev->mutex){....}-{3:3}, at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1003

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

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted 6.5.0-rc3-syzkaller-00275-gffabf7c73176 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x277/0x380 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x2ac/0x310 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
 watchdog+0xf29/0x11b0 kernel/hung_task.c:379
 kthread+0x33a/0x430 kernel/kthread.c:389
 ret_from_fork+0x2c/0x70 arch/x86/kernel/process.c:145
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:296
RIP: 0000:0x0
Code: Unable to access opcode bytes at 0xffffffffffffffd6.
RSP: 0000:0000000000000000 EFLAGS: 00000000 ORIG_RAX: 0000000000000000
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </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:48 [inline]
NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:86 [inline]
NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt+0x1b/0x20 drivers/acpi/processor_idle.c:112

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/07/29 11:56 upstream ffabf7c73176 92476829 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in lookup_one_unlocked
* Struck through repros no longer work on HEAD.