syzbot


INFO: task hung in xfs_buf_item_unpin

Status: auto-obsoleted due to no activity on 2023/08/21 23:02
Reported-by: syzbot+4eb75e297b6d0240b632@syzkaller.appspotmail.com
First crash: 367d, last: 355d
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in xfs_buf_item_unpin xfs C error done 147 103d 410d 0/26 auto-obsoleted due to no activity on 2024/03/11 08:02
linux-6.1 INFO: task hung in xfs_buf_item_unpin 10 285d 396d 0/3 auto-obsoleted due to no activity on 2023/10/11 09:07

Sample crash report:
INFO: task kworker/0:1H:149 blocked for more than 143 seconds.
      Not tainted 5.15.108-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:1H    state:D stack:    0 pid:  149 ppid:     2 flags:0x00000008
Workqueue: xfs-log/loop2 xlog_ioend_work
Call trace:
 __switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518
 context_switch kernel/sched/core.c:5026 [inline]
 __schedule+0xf10/0x1e38 kernel/sched/core.c:6372
 schedule+0x11c/0x1c8 kernel/sched/core.c:6455
 schedule_timeout+0xb8/0x344 kernel/time/timer.c:1860
 __down_common+0x2a4/0x4e0 kernel/locking/semaphore.c:224
 __down+0x18/0x24 kernel/locking/semaphore.c:241
 down+0x98/0xec kernel/locking/semaphore.c:62
 xfs_buf_lock+0x1f8/0x798 fs/xfs/xfs_buf.c:1080
 xfs_buf_item_unpin+0x1ec/0x808 fs/xfs/xfs_buf_item.c:546
 xfs_trans_committed_bulk+0x2b0/0x70c fs/xfs/xfs_trans.c:780
 xlog_cil_committed+0x22c/0xc20 fs/xfs/xfs_log_cil.c:631
 xlog_cil_process_committed+0x11c/0x174 fs/xfs/xfs_log_cil.c:659
 xlog_state_shutdown_callbacks+0x23c/0x324 fs/xfs/xfs_log.c:516
 xlog_force_shutdown+0x1a8/0x208 fs/xfs/xfs_log.c:3896
 xfs_do_force_shutdown+0x118/0x5e8 fs/xfs/xfs_fsops.c:529
 xlog_ioend_work+0xc0/0x114 fs/xfs/xfs_log.c:1364
 process_one_work+0x790/0x11b8 kernel/workqueue.c:2306
 worker_thread+0x910/0x1034 kernel/workqueue.c:2453
 kthread+0x37c/0x45c kernel/kthread.c:319
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870
INFO: task syz-executor.2:4355 blocked for more than 145 seconds.
      Not tainted 5.15.108-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.2  state:D stack:    0 pid: 4355 ppid:  4101 flags:0x00000009
Call trace:
 __switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518
 context_switch kernel/sched/core.c:5026 [inline]
 __schedule+0xf10/0x1e38 kernel/sched/core.c:6372
 schedule+0x11c/0x1c8 kernel/sched/core.c:6455
 xlog_wait+0x154/0x1d0 fs/xfs/xfs_log_priv.h:625
 xlog_wait_on_iclog+0x39c/0x684 fs/xfs/xfs_log.c:885
 xlog_force_lsn+0x5d4/0x7bc fs/xfs/xfs_log.c:3423
 xfs_log_force_seq+0x310/0x81c fs/xfs/xfs_log.c:3460
 __xfs_trans_commit+0x8cc/0xe98 fs/xfs/xfs_trans.c:890
 xfs_trans_commit+0x24/0x34 fs/xfs/xfs_trans.c:925
 xfs_sync_sb_buf+0x150/0x1ec fs/xfs/libxfs/xfs_sb.c:1100
 xfs_ioc_setlabel fs/xfs/xfs_ioctl.c:1875 [inline]
 xfs_file_ioctl+0x1ef4/0x297c fs/xfs/xfs_ioctl.c:1964
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl fs/ioctl.c:860 [inline]
 __arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:860
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:596
 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:614
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffff800014aa1660 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:268
2 locks held by kworker/u4:2/148:
 #0: ffff0000c0029138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x66c/0x11b8 kernel/workqueue.c:2279
 #1: ffff0001b481ec48 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x438/0x66c kernel/sched/psi.c:891
2 locks held by kworker/0:1H/149:
 #0: ffff00011d6b4d38 ((wq_completion)xfs-log/loop2){+.+.}-{0:0}, at: process_one_work+0x66c/0x11b8 kernel/workqueue.c:2279
 #1: ffff80001a3f7c00 ((work_completion)(&iclog->ic_end_io_work)){+.+.}-{0:0}, at: process_one_work+0x6ac/0x11b8 kernel/workqueue.c:2281
1 lock held by udevd/3585:
2 locks held by getty/3733:
 #0: ffff0000d31bb098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x40/0x50 drivers/tty/tty_ldsem.c:340
 #1: ffff80001a27b2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x414/0x1200 drivers/tty/n_tty.c:2147
1 lock held by syz-executor.4/4109:
 #0: ffff800014aa5be8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
 #0: ffff800014aa5be8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x320/0x660 kernel/rcu/tree_exp.h:840
2 locks held by kworker/0:9/4175:
 #0: ffff0000c0021d38 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x66c/0x11b8 kernel/workqueue.c:2279
 #1: ffff80001d8c7c00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x6ac/0x11b8 kernel/workqueue.c:2281
1 lock held by syz-executor.2/4355:
 #0: ffff00011fcd0460 (sb_writers#12){.+.+}-{0:0}, at: mnt_want_write_file+0x64/0x1e8 fs/namespace.c:421
3 locks held by kworker/u4:12/4752:
2 locks held by syz-executor.1/8240:
4 locks held by syz-executor.3/8249:

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


Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/04/23 23:01 linux-5.15.y 3299fb36854f 2b32bd34 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in xfs_buf_item_unpin
2023/04/12 09:34 linux-5.15.y d86dfc4d95cd 1a1596b6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: task hung in xfs_buf_item_unpin
* Struck through repros no longer work on HEAD.