syzbot


INFO: task hung in bfs_lookup (3)

Status: auto-obsoleted due to no activity on 2024/06/22 13:07
Subsystems: bfs
[Documentation on labels]
First crash: 347d, last: 334d
Similar bugs (5)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 INFO: task hung in bfs_lookup origin:upstream C error 1 33d 33d 0/3 upstream: reported C repro on 2025/02/28 02:48
upstream INFO: task hung in bfs_lookup (4) bfs 1 263d 263d 0/28 auto-obsoleted due to no activity on 2024/10/11 22:29
linux-4.19 INFO: task hung in bfs_lookup 1 846d 846d 0/1 auto-obsoleted due to no activity on 2023/04/07 07:53
upstream INFO: task hung in bfs_lookup bfs 1 715d 715d 0/28 auto-obsoleted due to no activity on 2023/07/17 03:03
upstream INFO: task hung in bfs_lookup (2) bfs 2 527d 571d 0/28 auto-obsoleted due to no activity on 2024/01/21 21:34

Sample crash report:
INFO: task syz-executor.4:7531 blocked for more than 143 seconds.
      Not tainted 6.9.0-rc6-syzkaller-00131-gf03359bca01b #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.4  state:D stack:25232 pid:7531  tgid:7525  ppid:6294   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5409 [inline]
 __schedule+0x1796/0x4a00 kernel/sched/core.c:6746
 __schedule_loop kernel/sched/core.c:6823 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6838
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6895
 __mutex_lock_common kernel/locking/mutex.c:684 [inline]
 __mutex_lock+0x6a4/0xd70 kernel/locking/mutex.c:752
 bfs_lookup+0x139/0x270 fs/bfs/dir.c:136
 __lookup_slow+0x28c/0x3f0 fs/namei.c:1692
 lookup_slow+0x53/0x70 fs/namei.c:1709
 walk_component+0x2e1/0x410 fs/namei.c:2004
 lookup_last fs/namei.c:2461 [inline]
 path_lookupat+0x16f/0x450 fs/namei.c:2485
 filename_lookup+0x256/0x610 fs/namei.c:2514
 user_path_at_empty+0x42/0x60 fs/namei.c:2921
 user_path_at include/linux/namei.h:57 [inline]
 do_sys_truncate+0xa7/0x190 fs/open.c:132
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb3ec27dd29
RSP: 002b:00007fb3ed04d0c8 EFLAGS: 00000246 ORIG_RAX: 000000000000004c
RAX: ffffffffffffffda RBX: 00007fb3ec3ac050 RCX: 00007fb3ec27dd29
RDX: 0000000000000000 RSI: 0000000000000031 RDI: 0000000020000000
RBP: 00007fb3ec2ca47e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007fb3ec3ac050 R15: 00007ffcebf130e8
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/u8:1/11:
1 lock held by ksoftirqd/0/15:
 #0: ffff8880b943e658 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:559
3 locks held by kworker/1:0/24:
 #0: ffff888015080948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3242 [inline]
 #0: ffff888015080948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x8e0/0x17c0 kernel/workqueue.c:3348
 #1: ffffc900001e7d00 (slab_caches_to_rcu_destroy_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3243 [inline]
 #1: ffffc900001e7d00 (slab_caches_to_rcu_destroy_work){+.+.}-{0:0}, at: process_scheduled_works+0x91b/0x17c0 kernel/workqueue.c:3348
 #2: ffffffff8e33a000 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x4c/0x550 kernel/rcu/tree.c:4073
1 lock held by khungtaskd/29:
 #0: ffffffff8e334da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline]
 #0: ffffffff8e334da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline]
 #0: ffffffff8e334da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6614
3 locks held by kworker/u8:9/2870:
2 locks held by getty/4825:
 #0: ffff88802b3e20a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000312b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b5/0x1e10 drivers/tty/n_tty.c:2201
3 locks held by syz-executor.1/5091:
2 locks held by syz-executor.4/7526:
2 locks held by syz-executor.4/7531:
 #0: ffff8880682f8168 (&type->i_mutex_dir_key#26){.+.+}-{3:3}, at: inode_lock_shared include/linux/fs.h:805 [inline]
 #0: ffff8880682f8168 (&type->i_mutex_dir_key#26){.+.+}-{3:3}, at: lookup_slow+0x45/0x70 fs/namei.c:1708
 #1: ffff888066b7dcd8 (&info->bfs_lock){+.+.}-{3:3}, at: bfs_lookup+0x139/0x270 fs/bfs/dir.c:136
1 lock held by udevd/8228:
 #0: ffff8880b943e658 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:559
2 locks held by syz-executor.4/9565:
4 locks held by syz-executor.0/9586:
2 locks held by syz-executor.0/9621:
 #0: ffff88802ac40420 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:409
 #1: ffff88804a5f0e00 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: inode_lock include/linux/fs.h:795 [inline]
 #1: ffff88804a5f0e00 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: open_last_lookups fs/namei.c:3563 [inline]
 #1: ffff88804a5f0e00 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: path_openat+0x7d3/0x3240 fs/namei.c:3796
2 locks held by syz-executor.0/9623:
 #0: ffff88802ac40420 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:409
 #1: ffff88804a5f0e00 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: inode_lock include/linux/fs.h:795 [inline]
 #1: ffff88804a5f0e00 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: open_last_lookups fs/namei.c:3563 [inline]
 #1: ffff88804a5f0e00 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: path_openat+0x7d3/0x3240 fs/namei.c:3796
2 locks held by syz-executor.0/9624:
 #0: ffff88802ac40420 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:409
 #1: ffff88804a5f0e00 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: inode_lock include/linux/fs.h:795 [inline]
 #1: ffff88804a5f0e00 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: open_last_lookups fs/namei.c:3563 [inline]
 #1: ffff88804a5f0e00 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: path_openat+0x7d3/0x3240 fs/namei.c:3796
2 locks held by syz-executor.0/9629:
 #0: ffff88802ac40420 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:409
 #1: ffff88804a5f0e00 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:830 [inline]
 #1: ffff88804a5f0e00 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: filename_create+0x260/0x540 fs/namei.c:3892
2 locks held by syz-executor.0/9632:
 #0: ffff88802ac40420 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:409
 #1: ffff88804a5f0e00 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: inode_lock include/linux/fs.h:795 [inline]
 #1: ffff88804a5f0e00 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: open_last_lookups fs/namei.c:3563 [inline]
 #1: ffff88804a5f0e00 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: path_openat+0x7d3/0x3240 fs/namei.c:3796
2 locks held by syz-executor.0/9633:
 #0: ffff8880b953e658 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:559
 #1: ffff8880b9528948 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x441/0x770 kernel/sched/psi.c:988
2 locks held by dhcpcd-run-hook/9635:

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

NMI backtrace for cpu 1
CPU: 1 PID: 29 Comm: khungtaskd Not tainted 6.9.0-rc6-syzkaller-00131-gf03359bca01b #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+0x241/0x360 lib/dump_stack.c:114
 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline]
 watchdog+0xfde/0x1020 kernel/hung_task.c:380
 kthread+0x2f0/0x390 kernel/kthread.c:388
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 5093 Comm: kworker/0:3 Not tainted 6.9.0-rc6-syzkaller-00131-gf03359bca01b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Workqueue: events nsim_dev_trap_report_work
RIP: 0010:chacha_permute+0x4d8/0x1050 lib/crypto/chacha.c:62
Code: 89 44 24 10 41 31 c7 41 c1 c7 07 44 89 74 24 48 44 89 e0 44 01 f0 89 44 24 54 31 c3 c1 c3 07 89 f0 41 89 fc 01 f8 89 44 24 20 <41> 31 c3 41 c1 c3 07 44 89 5c 24 0c 8b 84 24 84 00 00 00 3b 84 24
RSP: 0018:ffffc900038e7548 EFLAGS: 00000083
RAX: 00000000a29afbea RBX: 0000000028358ccc RCX: 0000000012c006e0
RDX: 0000000087d9ae75 RSI: 00000000c4223cfa RDI: 00000000de78bef0
RBP: 000000008404c65c R08: 00000000d9289866 R09: 000000007f36fd43
R10: 0000000044655dbc R11: 00000000f15d46c0 R12: 00000000de78bef0
R13: 0000000067026236 R14: 0000000082a67d82 R15: 00000000f0ccd0fb
FS:  0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fda1a8d66e4 CR3: 000000006794e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 chacha_block_generic+0x9f/0x1340 lib/crypto/chacha.c:83
 chacha20_block include/crypto/chacha.h:36 [inline]
 crng_fast_key_erasure drivers/char/random.c:305 [inline]
 crng_make_state+0x38d/0xa80 drivers/char/random.c:371
 _get_random_bytes+0xd7/0x2c0 drivers/char/random.c:385
 eth_random_addr include/linux/etherdevice.h:232 [inline]
 nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:755 [inline]
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline]
 nsim_dev_trap_report_work+0x301/0xaa0 drivers/net/netdevsim/dev.c:850
 process_one_work kernel/workqueue.c:3267 [inline]
 process_scheduled_works+0xa10/0x17c0 kernel/workqueue.c:3348
 worker_thread+0x86d/0xd70 kernel/workqueue.c:3429
 kthread+0x2f0/0x390 kernel/kthread.c:388
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Crashes (20):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/05/03 13:05 upstream f03359bca01b dd26401e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in bfs_lookup
2024/04/30 14:09 upstream 98369dccd2f8 27e33c58 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: task hung in bfs_lookup
2024/04/28 02:12 upstream 5d12ed4bea43 07b455f9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: task hung in bfs_lookup
2024/04/22 05:55 upstream 48cf398f15fc af24b050 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in bfs_lookup
2024/04/21 18:57 upstream 977b1ef51866 af24b050 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in bfs_lookup
2024/04/21 17:50 upstream 977b1ef51866 af24b050 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in bfs_lookup
2024/04/21 16:22 upstream 977b1ef51866 af24b050 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in bfs_lookup
2024/04/20 15:33 upstream 13a2e429f644 af24b050 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in bfs_lookup
2024/04/20 15:32 upstream 13a2e429f644 af24b050 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in bfs_lookup
2024/04/20 15:32 upstream 13a2e429f644 af24b050 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in bfs_lookup
2024/04/20 15:31 upstream 13a2e429f644 af24b050 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in bfs_lookup
2024/04/20 15:29 upstream 13a2e429f644 af24b050 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in bfs_lookup
2024/04/20 15:29 upstream 13a2e429f644 af24b050 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in bfs_lookup
2024/04/20 15:28 upstream 13a2e429f644 af24b050 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in bfs_lookup
2024/04/20 15:27 upstream 13a2e429f644 af24b050 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in bfs_lookup
2024/04/20 15:26 upstream 13a2e429f644 af24b050 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in bfs_lookup
2024/04/20 15:25 upstream 13a2e429f644 af24b050 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in bfs_lookup
2024/04/20 14:44 upstream 13a2e429f644 af24b050 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in bfs_lookup
2024/04/22 09:05 linux-next 7b4f2bc91c15 af24b050 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in bfs_lookup
2024/04/21 16:56 linux-next 7b4f2bc91c15 af24b050 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in bfs_lookup
* Struck through repros no longer work on HEAD.