syzbot


INFO: task hung in lock_buffer

Status: auto-obsoleted due to no activity on 2023/08/22 15:19
Reported-by: syzbot+32673b66035b3fda5955@syzkaller.appspotmail.com
First crash: 617d, last: 598d
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in lock_buffer ext4 21 588d 661d 0/28 auto-obsoleted due to no activity on 2023/08/03 10:57
linux-5.15 INFO: task hung in lock_buffer 13 578d 621d 0/3 auto-obsoleted due to no activity on 2023/08/22 15:17

Sample crash report:
INFO: task syz-executor.4:6777 blocked for more than 144 seconds.
      Not tainted 6.1.25-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.4  state:D stack:0     pid:6777  ppid:4348   flags:0x00000009
Call trace:
 __switch_to+0x320/0x754 arch/arm64/kernel/process.c:553
 context_switch kernel/sched/core.c:5241 [inline]
 __schedule+0xee4/0x1c98 kernel/sched/core.c:6554
 schedule+0xc4/0x170 kernel/sched/core.c:6630
 io_schedule+0x8c/0x188 kernel/sched/core.c:8774
 bit_wait_io+0x1c/0xac kernel/sched/wait_bit.c:209
 __wait_on_bit_lock+0xcc/0x1e8 kernel/sched/wait_bit.c:90
 out_of_line_wait_on_bit_lock+0x194/0x21c kernel/sched/wait_bit.c:117
 wait_on_bit_lock_io include/linux/wait_bit.h:208 [inline]
 __lock_buffer fs/buffer.c:69 [inline]
 lock_buffer+0xf8/0x14c include/linux/buffer_head.h:397
 __sync_dirty_buffer+0x6c/0x300 fs/buffer.c:2732
 sync_dirty_buffer+0x24/0x34 fs/buffer.c:2758
 __ext4_handle_dirty_metadata+0x188/0x70c fs/ext4/ext4_jbd2.c:381
 ext4_convert_inline_data_nolock+0x66c/0xbc4 fs/ext4/inline.c:1255
 ext4_convert_inline_data+0x388/0x508 fs/ext4/inline.c:2066
 ext4_fallocate+0x124/0x1df0 fs/ext4/extents.c:4702
 vfs_fallocate+0x478/0x5b4 fs/open.c:323
 ioctl_preallocate+0x278/0x324 fs/ioctl.c:290
 do_vfs_ioctl+0x1ad8/0x26f8 fs/ioctl.c:849
 __do_sys_ioctl fs/ioctl.c:868 [inline]
 __se_sys_ioctl fs/ioctl.c:856 [inline]
 __arm64_sys_ioctl+0xe4/0x1c8 fs/ioctl.c:856
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206
 el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
 #0: ffff800015754930 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x44/0xcf4 kernel/rcu/tasks.h:510
1 lock held by rcu_tasks_trace/13:
 #0: ffff800015755130 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x44/0xcf4 kernel/rcu/tasks.h:510
1 lock held by khungtaskd/28:
 #0: ffff800015754760 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:305
2 locks held by kworker/u4:2/39:
 #0: ffff0000c0029138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x664/0x1404 kernel/workqueue.c:2262
 #1: ffff80001afd7c20 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work+0x6a8/0x1404 kernel/workqueue.c:2264
2 locks held by getty/3987:
 #0: ffff0000d3ed1098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340
 #1: ffff80001ca202f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x414/0x1210 drivers/tty/n_tty.c:2177
3 locks held by kworker/0:4/4405:
2 locks held by kworker/u4:6/4649:
 #0: ffff0000c0029138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x664/0x1404 kernel/workqueue.c:2262
 #1: ffff80001fe87c20 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work+0x6a8/0x1404 kernel/workqueue.c:2264
3 locks held by kworker/u4:12/5129:
3 locks held by syz-executor.4/6777:
 #0: ffff00012c140460 (sb_writers#3){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2950 [inline]
 #0: ffff00012c140460 (sb_writers#3){.+.+}-{0:0}, at: vfs_fallocate+0x404/0x5b4 fs/open.c:322
 #1: ffff0000dd252218 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: inode_lock include/linux/fs.h:756 [inline]
 #1: ffff0000dd252218 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: ext4_fallocate+0x11c/0x1df0 fs/ext4/extents.c:4701
 #2: ffff0000dd251ee0 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_lock_xattr fs/ext4/xattr.h:155 [inline]
 #2: ffff0000dd251ee0 (&ei->xattr_sem){++++}-{3:3}, at: ext4_convert_inline_data+0x2d8/0x508 fs/ext4/inline.c:2064
1 lock held by syz-executor.5/9043:
1 lock held by syz-executor.0/9049:
 #0: ffff0000e0718810 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:756 [inline]
 #0: ffff0000e0718810 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release net/socket.c:651 [inline]
 #0: ffff0000e0718810 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: sock_close+0x80/0x1fc net/socket.c:1370
2 locks held by syz-executor.4/9057:
5 locks held by syz-executor.2/9059:

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


Crashes (14):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/04/26 01:08 linux-6.1.y f17b0ab65d17 65320f8e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in lock_buffer
2023/04/24 20:07 linux-6.1.y f17b0ab65d17 fdc18293 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in lock_buffer
2023/04/21 19:57 linux-6.1.y f17b0ab65d17 2b32bd34 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in lock_buffer
2023/04/20 04:14 linux-6.1.y 0102425ac76b a219f34e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in lock_buffer
2023/04/11 12:27 linux-6.1.y 543aff194ab6 71147e29 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in lock_buffer
2023/04/11 02:52 linux-6.1.y 543aff194ab6 71147e29 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in lock_buffer
2023/04/10 13:02 linux-6.1.y 543aff194ab6 71147e29 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in lock_buffer
2023/04/10 06:29 linux-6.1.y 543aff194ab6 71147e29 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in lock_buffer
2023/04/10 03:03 linux-6.1.y 543aff194ab6 71147e29 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in lock_buffer
2023/04/09 21:30 linux-6.1.y 543aff194ab6 71147e29 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in lock_buffer
2023/04/08 16:13 linux-6.1.y 543aff194ab6 71147e29 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in lock_buffer
2023/04/08 15:17 linux-6.1.y 543aff194ab6 71147e29 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in lock_buffer
2023/04/08 13:47 linux-6.1.y 543aff194ab6 71147e29 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 INFO: task hung in lock_buffer
2023/04/07 03:51 linux-6.1.y 543aff194ab6 00ce4c67 .config console log report info ci2-linux-6-1-kasan-arm64 INFO: task hung in lock_buffer
* Struck through repros no longer work on HEAD.