syzbot


INFO: task hung in __sync_dirty_buffer

Status: upstream: reported C repro on 2020/09/29 05:34
Subsystems: ext4 nilfs2
[Documentation on labels]
Reported-by: syzbot+113a4a32dcf5b9c53b61@syzkaller.appspotmail.com
First crash: 1333d, last: 457d
Fix bisection: failed (error log, bisect log)
  
Similar bugs (4)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 INFO: task hung in __sync_dirty_buffer ext4 nilfs2 C error 25 445d 1321d 0/1 upstream: reported C repro on 2020/10/11 09:03
linux-6.1 INFO: task hung in __sync_dirty_buffer 2 380d 403d 0/3 auto-obsoleted due to no activity on 2023/08/23 09:07
linux-5.15 INFO: task hung in __sync_dirty_buffer 10 374d 412d 0/3 auto-obsoleted due to no activity on 2023/08/22 15:19
upstream INFO: task hung in __sync_dirty_buffer ext4 C inconclusive error 832 347d 995d 22/26 fixed on 2023/07/01 16:05
Fix bisection attempts (22)
Created Duration User Patch Repo Result
2022/10/13 02:08 0m bisect fix linux-4.14.y error job log (0)
2022/08/25 00:44 33m bisect fix linux-4.14.y job log (0) log
2022/07/26 00:16 28m bisect fix linux-4.14.y job log (0) log
2022/06/19 07:43 21m bisect fix linux-4.14.y job log (0) log
2022/04/28 17:17 20m bisect fix linux-4.14.y job log (0) log
2022/03/29 16:52 25m bisect fix linux-4.14.y job log (0) log
2022/02/25 21:56 33m bisect fix linux-4.14.y job log (0) log
2022/01/26 20:42 25m bisect fix linux-4.14.y job log (0) log
2021/12/27 20:17 24m bisect fix linux-4.14.y job log (0) log
2021/11/27 19:48 23m bisect fix linux-4.14.y job log (0) log
2021/10/28 19:20 27m bisect fix linux-4.14.y job log (0) log
2021/09/25 11:05 26m bisect fix linux-4.14.y job log (0) log
2021/08/26 10:37 24m bisect fix linux-4.14.y job log (0) log
2021/07/27 10:10 23m bisect fix linux-4.14.y job log (0) log
2021/06/27 09:08 26m bisect fix linux-4.14.y job log (0) log
2021/04/27 11:01 38m bisect fix linux-4.14.y job log (0) log
2021/03/28 09:09 29m bisect fix linux-4.14.y job log (0) log
2021/02/26 08:38 30m bisect fix linux-4.14.y job log (0) log
2021/01/27 08:00 38m bisect fix linux-4.14.y job log (0) log
2020/12/28 06:39 33m bisect fix linux-4.14.y job log (0) log
2020/11/28 06:04 35m bisect fix linux-4.14.y job log (0) log
2020/10/29 05:33 30m bisect fix linux-4.14.y job log (0) log

Sample crash report:
         will be removed in v5.15!
======================================================
EXT4-fs (loop0): warning: checktime reached, running e2fsck is recommended
EXT4-fs (loop0): mounted filesystem without journal. Opts: ,errors=continue
INFO: task syz-executor267:7990 blocked for more than 140 seconds.
      Not tainted 4.14.305-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor267 D26720  7990   7989 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2811 [inline]
 __schedule+0x88b/0x1de0 kernel/sched/core.c:3386
 schedule+0x8d/0x1b0 kernel/sched/core.c:3430
 io_schedule+0xb5/0x120 kernel/sched/core.c:5034
 bit_wait_io+0x12/0x90 kernel/sched/wait_bit.c:249
 __wait_on_bit_lock+0xc2/0x1d0 kernel/sched/wait_bit.c:89
 out_of_line_wait_on_bit_lock+0xbc/0xd0 kernel/sched/wait_bit.c:116
 wait_on_bit_lock_io include/linux/wait_bit.h:213 [inline]
 __lock_buffer+0x43/0x50 fs/buffer.c:72
 lock_buffer include/linux/buffer_head.h:408 [inline]
 __sync_dirty_buffer+0x214/0x290 fs/buffer.c:3235
 __ext4_handle_dirty_metadata+0x169/0x480 fs/ext4/ext4_jbd2.c:300
 ext4_finish_convert_inline_dir fs/ext4/inline.c:1190 [inline]
 ext4_convert_inline_data_nolock+0x8d8/0xc60 fs/ext4/inline.c:1266
 ext4_try_add_inline_entry+0x2a5/0x4a0 fs/ext4/inline.c:1339
 ext4_add_entry+0x2ee/0xa40 fs/ext4/namei.c:2138
 ext4_mkdir+0x5cf/0xbd0 fs/ext4/namei.c:2732
 vfs_mkdir+0x463/0x6e0 fs/namei.c:3851
 SYSC_mkdirat fs/namei.c:3874 [inline]
 SyS_mkdirat+0x1fd/0x270 fs/namei.c:3858
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x5e/0xd3
RIP: 0033:0x7f5eb5779259
RSP: 002b:00007ffe31127f08 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 0030656c69662f2e RCX: 00007f5eb5779259
RDX: 0000000000000000 RSI: 0000000020000540 RDI: 0000000000000004
RBP: 0000000000000000 R08: 00007f5eb57e7ec0 R09: 00007f5eb57e7ec0
R10: 00007f5eb57e7ec0 R11: 0000000000000246 R12: 00007ffe31127f30
R13: 0000000000000000 R14: 431bde82d7b634db R15: 0000000000000000

Showing all locks held in the system:
1 lock held by khungtaskd/1533:
 #0:  (tasklist_lock){.+.+}, at: [<ffffffff8702d99c>] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548
1 lock held by in:imklog/7714:
 #0:  (&f->f_pos_lock){+.+.}, at: [<ffffffff818d8ebb>] __fdget_pos+0x1fb/0x2b0 fs/file.c:819
3 locks held by syz-executor267/7990:
 #0:  (sb_writers#3){.+.+}, at: [<ffffffff818e1f2a>] sb_start_write include/linux/fs.h:1551 [inline]
 #0:  (sb_writers#3){.+.+}, at: [<ffffffff818e1f2a>] mnt_want_write+0x3a/0xb0 fs/namespace.c:386
 #1:  (&type->i_mutex_dir_key#3/1){+.+.}, at: [<ffffffff818a97fa>] inode_lock_nested include/linux/fs.h:754 [inline]
 #1:  (&type->i_mutex_dir_key#3/1){+.+.}, at: [<ffffffff818a97fa>] filename_create+0x12a/0x3f0 fs/namei.c:3676
 #2:  (&ei->xattr_sem){++++}, at: [<ffffffff81b9a462>] ext4_write_lock_xattr fs/ext4/xattr.h:154 [inline]
 #2:  (&ei->xattr_sem){++++}, at: [<ffffffff81b9a462>] ext4_try_add_inline_entry+0xc2/0x4a0 fs/ext4/inline.c:1297

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

NMI backtrace for cpu 0
CPU: 0 PID: 1533 Comm: khungtaskd Not tainted 4.14.305-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1b2/0x281 lib/dump_stack.c:58
 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x13a/0x180 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline]
 watchdog+0x5b9/0xb40 kernel/hung_task.c:274
 kthread+0x30d/0x420 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:406
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4618 Comm: systemd-journal Not tainted 4.14.305-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023
task: ffff8880a1ad86c0 task.stack: ffff8880a1ae0000
RIP: 0010:mark_held_locks+0xc3/0xf0 kernel/locking/lockdep.c:2859
RSP: 0018:ffff8880a1ae7de8 EFLAGS: 00000092
RAX: 0000000000000001 RBX: ffff8880a1ad86c0 RCX: 0000000000000000
RDX: 1ffff1101435b1e8 RSI: 0000000000000001 RDI: ffff8880a1ad8f40
RBP: ffffffff817ee4f0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000286
R13: ffff8880a1ad86c0 R14: 00000000ffffff9c R15: 00005563a42a59a3
FS:  00007f854c54a8c0(0000) GS:ffff8880ba500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8549919018 CR3: 00000000a1827000 CR4: 00000000003406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __trace_hardirqs_on_caller kernel/locking/lockdep.c:2883 [inline]
 trace_hardirqs_on_caller+0x3a8/0x580 kernel/locking/lockdep.c:2930
 kmem_cache_free+0x160/0x2b0 mm/slab.c:3759
 __put_cred+0x1a1/0x210 kernel/cred.c:151
 put_cred include/linux/cred.h:274 [inline]
 SYSC_faccessat fs/open.c:444 [inline]
 SyS_faccessat+0x52a/0x680 fs/open.c:353
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x5e/0xd3
RIP: 0033:0x7f854b8059c7
RSP: 002b:00007ffe4883d118 EFLAGS: 00000246 ORIG_RAX: 0000000000000015
RAX: ffffffffffffffda RBX: 00007ffe48840140 RCX: 00007f854b8059c7
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00005563a42a59a3
RBP: 00007ffe4883d260 R08: 00005563a429b3e5 R09: 0000000000000018
R10: 0000000000000069 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00005563a45078a0 R15: 00007ffe4883d750
Code: 45 d5 a8 04 74 0c 4c 89 ef e8 0a ef ff ff 85 c0 74 11 83 c3 01 41 39 9d 80 08 00 00 7f af b8 01 00 00 00 48 83 c4 08 5b 5d 41 5c <41> 5d 41 5e 41 5f c3 89 34 24 e8 7e 8f 3d 00 8b 34 24 e9 5f ff 

Crashes (9):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/02/22 09:56 linux-4.14.y a8ad60f2af58 42a4d508 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-4-14 INFO: task hung in __sync_dirty_buffer
2023/01/17 01:11 linux-4.14.y c4215ee4771b a63719e7 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro #1] [mounted in repro #2] ci2-linux-4-14 INFO: task hung in __sync_dirty_buffer
2022/12/29 11:29 linux-4.14.y c4215ee4771b 44712fbc .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-4-14 INFO: task hung in __sync_dirty_buffer
2022/10/28 10:14 linux-4.14.y 41f36d7859a7 5c716ff6 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-4-14 INFO: task hung in __sync_dirty_buffer
2022/06/25 22:09 linux-4.14.y f051383ef03b a371c43c .config console log report syz C ci2-linux-4-14 INFO: task hung in __sync_dirty_buffer
2022/05/20 07:43 linux-4.14.y dffb5c6ff09c cb1ac2e7 .config console log report syz C ci2-linux-4-14 INFO: task hung in __sync_dirty_buffer
2021/05/28 08:54 linux-4.14.y ad8397a84e1e 858ea628 .config console log report syz C ci2-linux-4-14 INFO: task hung in __sync_dirty_buffer
2021/05/16 12:06 linux-4.14.y 7d7d1c0ab3eb f54a5c09 .config console log report syz C ci2-linux-4-14 INFO: task hung in __sync_dirty_buffer
2020/09/29 05:33 linux-4.14.y cbfa1702aaf6 1b88c6d5 .config console log report syz C ci2-linux-4-14
* Struck through repros no longer work on HEAD.