syzbot


INFO: task hung in __sync_dirty_buffer

Status: upstream: reported C repro on 2020/10/11 09:03
Subsystems: ext4 nilfs2
[Documentation on labels]
Reported-by: syzbot+d0c2e06c668c2060c48f@syzkaller.appspotmail.com
First crash: 1287d, last: 412d
Fix bisection: failed (error log, bisect log)
  
Similar bugs (4)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.14 INFO: task hung in __sync_dirty_buffer ext4 nilfs2 C error 9 423d 1300d 0/1 upstream: reported C repro on 2020/09/29 05:34
linux-6.1 INFO: task hung in __sync_dirty_buffer 2 347d 370d 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 341d 378d 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 314d 962d 22/26 fixed on 2023/07/01 16:05
Fix bisection attempts (13)
Created Duration User Patch Repo Result
2021/10/21 04:05 10m bisect fix linux-4.19.y error job log (0)
2021/09/21 03:36 28m bisect fix linux-4.19.y job log (0) log
2021/08/22 03:06 29m bisect fix linux-4.19.y job log (0) log
2021/07/23 02:31 35m bisect fix linux-4.19.y job log (0) log
2021/06/22 20:15 28m bisect fix linux-4.19.y job log (0) log
2021/04/23 00:49 32m bisect fix linux-4.19.y job log (0) log
2021/03/23 19:39 31m bisect fix linux-4.19.y job log (0) log
2021/02/21 18:05 30m bisect fix linux-4.19.y job log (0) log
2021/02/18 08:18 19m bisect fix linux-4.19.y error job log (0)
2021/02/08 11:03 0m bisect fix linux-4.19.y error job log (0)
2021/01/09 10:20 33m bisect fix linux-4.19.y job log (0) log
2020/12/10 09:32 35m bisect fix linux-4.19.y job log (0) log
2020/11/10 09:02 29m bisect fix linux-4.19.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-executor851:8114 blocked for more than 140 seconds.
      Not tainted 4.19.211-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor851 D25664  8114   8113 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2828 [inline]
 __schedule+0x887/0x2040 kernel/sched/core.c:3517
 schedule+0x8d/0x1b0 kernel/sched/core.c:3561
 io_schedule+0xb5/0x120 kernel/sched/core.c:5181
 bit_wait_io+0x12/0x90 kernel/sched/wait_bit.c:207
 __wait_on_bit_lock+0xb5/0x170 kernel/sched/wait_bit.c:89
 out_of_line_wait_on_bit_lock+0xd2/0x100 kernel/sched/wait_bit.c:116
 wait_on_bit_lock_io include/linux/wait_bit.h:208 [inline]
 __lock_buffer+0x52/0x60 fs/buffer.c:65
 lock_buffer include/linux/buffer_head.h:374 [inline]
 __sync_dirty_buffer+0x2a6/0x320 fs/buffer.c:3178
 __ext4_handle_dirty_metadata+0x234/0x590 fs/ext4/ext4_jbd2.c:300
 ext4_finish_convert_inline_dir fs/ext4/inline.c:1173 [inline]
 ext4_convert_inline_data_nolock+0x967/0xd10 fs/ext4/inline.c:1249
 ext4_try_add_inline_entry+0x338/0x570 fs/ext4/inline.c:1322
 ext4_add_entry+0x33c/0xbb0 fs/ext4/namei.c:2117
 ext4_mkdir+0x6f5/0xe10 fs/ext4/namei.c:2711
 vfs_mkdir+0x508/0x7a0 fs/namei.c:3819
 do_mkdirat+0x262/0x2d0 fs/namei.c:3842
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f996efc7259
Code: Bad RIP value.
RSP: 002b:00007ffe888d18d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 0030656c69662f2e RCX: 00007f996efc7259
RDX: 0000000000000000 RSI: 0000000020000540 RDI: 0000000000000004
RBP: 0000000000000000 R08: 00007f996f035ec0 R09: 00007f996f035ec0
R10: 00007f996f035ec0 R11: 0000000000000246 R12: 00007ffe888d1900
R13: 0000000000000000 R14: 431bde82d7b634db R15: 0000000000000000

Showing all locks held in the system:
1 lock held by khungtaskd/1570:
 #0: 00000000771a61f9 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4441
1 lock held by in:imklog/7726:
 #0: 000000004947c36d (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x26f/0x310 fs/file.c:767
3 locks held by syz-executor851/8114:
 #0: 00000000ab4d2a4e (sb_writers#3){.+.+}, at: sb_start_write include/linux/fs.h:1579 [inline]
 #0: 00000000ab4d2a4e (sb_writers#3){.+.+}, at: mnt_want_write+0x3a/0xb0 fs/namespace.c:360
 #1: 00000000bfca778b (&type->i_mutex_dir_key#3/1){+.+.}, at: inode_lock_nested include/linux/fs.h:783 [inline]
 #1: 00000000bfca778b (&type->i_mutex_dir_key#3/1){+.+.}, at: filename_create+0x15a/0x490 fs/namei.c:3638
 #2: 0000000075efa324 (&ei->xattr_sem){++++}, at: ext4_write_lock_xattr fs/ext4/xattr.h:141 [inline]
 #2: 0000000075efa324 (&ei->xattr_sem){++++}, at: ext4_try_add_inline_entry+0xfc/0x570 fs/ext4/inline.c:1280

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

NMI backtrace for cpu 1
CPU: 1 PID: 1570 Comm: khungtaskd Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fc/0x2ef lib/dump_stack.c:118
 nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1a6/0x1f0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline]
 watchdog+0x991/0xe60 kernel/hung_task.c:287
 kthread+0x33f/0x460 kernel/kthread.c:259
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 10 Comm: rcu_preempt Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023
RIP: 0010:bytes_is_nonzero mm/kasan/kasan.c:167 [inline]
RIP: 0010:memory_is_nonzero mm/kasan/kasan.c:184 [inline]
RIP: 0010:memory_is_poisoned_n mm/kasan/kasan.c:210 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/kasan.c:241 [inline]
RIP: 0010:check_memory_region_inline mm/kasan/kasan.c:257 [inline]
RIP: 0010:check_memory_region+0xcb/0x170 mm/kasan/kasan.c:267
Code: 0e 80 38 00 74 f2 48 85 c0 0f 85 9c 00 00 00 5b 5d 41 5c c3 48 85 d2 74 f6 48 01 ea eb 09 48 83 c0 01 48 39 d0 74 e8 80 38 00 <74> f2 eb d8 41 bc 08 00 00 00 48 89 ea 45 29 dc 4e 8d 5c 25 00 eb
RSP: 0018:ffff8880b5a67b10 EFLAGS: 00000046
RAX: fffffbfff19ae805 RBX: fffffbfff19ae806 RCX: ffffffff814afa31
RDX: fffffbfff19ae806 RSI: 0000000000000004 RDI: ffffffff8cd74028
RBP: fffffbfff19ae805 R08: 0000000000000001 R09: fffffbfff19ae805
R10: ffffffff8cd7402b R11: 0000000000000000 R12: 0000000000000000
R13: ffff8880b5a4e280 R14: ffffffff89f889d8 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3f70d1a000 CR3: 00000000a108b000 CR4: 00000000003406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 atomic_inc include/asm-generic/atomic-instrumented.h:109 [inline]
 __lock_acquire+0x251/0x3ff0 kernel/locking/lockdep.c:3308
 lock_acquire+0x170/0x3c0 kernel/locking/lockdep.c:3908
 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
 _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:144
 spin_lock include/linux/spinlock.h:329 [inline]
 rcu_gp_init kernel/rcu/tree.c:1939 [inline]
 rcu_gp_kthread+0x505/0x21c0 kernel/rcu/tree.c:2178
 kthread+0x33f/0x460 kernel/kthread.c:259
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415

Crashes (25):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/02/20 17:24 linux-4.19.y 3f8a27f9e27b bcdf85f8 .config console log report syz C [disk image] [vmlinux] [mounted in repro] ci2-linux-4-19 INFO: task hung in __sync_dirty_buffer
2023/02/20 01:12 linux-4.19.y 3f8a27f9e27b bcdf85f8 .config console log report syz C [disk image] [vmlinux] [mounted in repro] ci2-linux-4-19 INFO: task hung in __sync_dirty_buffer
2023/01/22 04:35 linux-4.19.y 3f8a27f9e27b cc0f9968 .config console log report syz C [disk image] [vmlinux] [mounted in repro #1] [mounted in repro #2] ci2-linux-4-19 INFO: task hung in __sync_dirty_buffer
2022/12/11 09:44 linux-4.19.y 3f8a27f9e27b 67be1ae7 .config console log report syz C [disk image] [vmlinux] [mounted in repro] ci2-linux-4-19 INFO: task hung in __sync_dirty_buffer
2022/06/25 17:44 linux-4.19.y 3f8a27f9e27b a371c43c .config console log report syz C ci2-linux-4-19 INFO: task hung in __sync_dirty_buffer
2022/05/20 03:12 linux-4.19.y 3f8a27f9e27b cb1ac2e7 .config console log report syz C ci2-linux-4-19 INFO: task hung in __sync_dirty_buffer
2021/05/23 19:44 linux-4.19.y 1e986fe9ad15 3c7fef33 .config console log report syz C ci2-linux-4-19 INFO: task hung in __sync_dirty_buffer
2021/05/18 12:54 linux-4.19.y 3c8c23092588 a343ba6b .config console log report syz C ci2-linux-4-19 INFO: task hung in __sync_dirty_buffer
2020/10/11 09:02 linux-4.19.y a1b977b49b66 4a77ae0b .config console log report syz C ci2-linux-4-19
2023/03/05 21:36 linux-4.19.y 3f8a27f9e27b f8902b57 .config console log report info [disk image] [vmlinux] ci2-linux-4-19 INFO: task hung in __sync_dirty_buffer
2023/02/27 21:07 linux-4.19.y 3f8a27f9e27b 9189cb53 .config console log report info [disk image] [vmlinux] ci2-linux-4-19 INFO: task hung in __sync_dirty_buffer
2023/02/14 22:21 linux-4.19.y 3f8a27f9e27b e62ba3c1 .config console log report info [disk image] [vmlinux] ci2-linux-4-19 INFO: task hung in __sync_dirty_buffer
2023/02/12 07:19 linux-4.19.y 3f8a27f9e27b 93e26d60 .config console log report info [disk image] [vmlinux] ci2-linux-4-19 INFO: task hung in __sync_dirty_buffer
2023/01/29 13:45 linux-4.19.y 3f8a27f9e27b 9dfcf09c .config console log report info [disk image] [vmlinux] ci2-linux-4-19 INFO: task hung in __sync_dirty_buffer
2023/01/27 23:15 linux-4.19.y 3f8a27f9e27b 9dfcf09c .config console log report info [disk image] [vmlinux] ci2-linux-4-19 INFO: task hung in __sync_dirty_buffer
2023/01/27 22:54 linux-4.19.y 3f8a27f9e27b 9dfcf09c .config console log report info [disk image] [vmlinux] ci2-linux-4-19 INFO: task hung in __sync_dirty_buffer
2023/01/25 00:13 linux-4.19.y 3f8a27f9e27b 9dfcf09c .config console log report info [disk image] [vmlinux] ci2-linux-4-19 INFO: task hung in __sync_dirty_buffer
2023/01/23 00:14 linux-4.19.y 3f8a27f9e27b cc0f9968 .config console log report info [disk image] [vmlinux] ci2-linux-4-19 INFO: task hung in __sync_dirty_buffer
2023/01/19 05:23 linux-4.19.y 3f8a27f9e27b 4620c2d9 .config console log report info [disk image] [vmlinux] ci2-linux-4-19 INFO: task hung in __sync_dirty_buffer
2023/01/17 19:55 linux-4.19.y 3f8a27f9e27b 42660d9e .config console log report info [disk image] [vmlinux] ci2-linux-4-19 INFO: task hung in __sync_dirty_buffer
2023/01/04 22:39 linux-4.19.y 3f8a27f9e27b 1dac8c7a .config console log report info [disk image] [vmlinux] ci2-linux-4-19 INFO: task hung in __sync_dirty_buffer
2022/12/17 10:12 linux-4.19.y 3f8a27f9e27b 05494336 .config console log report info [disk image] [vmlinux] ci2-linux-4-19 INFO: task hung in __sync_dirty_buffer
2022/11/27 13:52 linux-4.19.y 3f8a27f9e27b f4470a7b .config console log report info [disk image] [vmlinux] ci2-linux-4-19 INFO: task hung in __sync_dirty_buffer
2022/05/19 22:14 linux-4.19.y 3f8a27f9e27b cb1ac2e7 .config console log report info ci2-linux-4-19 INFO: task hung in __sync_dirty_buffer
2021/04/23 08:27 linux-4.19.y 2965db2e004c 590921a5 .config console log report info ci2-linux-4-19 INFO: task hung in __sync_dirty_buffer
* Struck through repros no longer work on HEAD.