syzbot


INFO: task hung in __sync_dirty_buffer

Status: auto-obsoleted due to no activity on 2023/08/22 15:19
Reported-by: syzbot+fe0a0d156f3505e58f99@syzkaller.appspotmail.com
First crash: 414d, last: 377d
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 459d 1335d 0/1 upstream: reported C repro on 2020/09/29 05:34
linux-4.19 INFO: task hung in __sync_dirty_buffer ext4 nilfs2 C error 25 448d 1323d 0/1 upstream: reported C repro on 2020/10/11 09:03
linux-6.1 INFO: task hung in __sync_dirty_buffer 2 382d 406d 0/3 auto-obsoleted due to no activity on 2023/08/23 09:07
upstream INFO: task hung in __sync_dirty_buffer ext4 C inconclusive error 832 349d 998d 22/26 fixed on 2023/07/01 16:05

Sample crash report:
INFO: task syz-executor.2:11220 blocked for more than 143 seconds.
      Not tainted 5.15.111-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.2  state:D stack:23712 pid:11220 ppid:  3547 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5026 [inline]
 __schedule+0x12c4/0x4590 kernel/sched/core.c:6372
 schedule+0x11b/0x1f0 kernel/sched/core.c:6455
 io_schedule+0x88/0x100 kernel/sched/core.c:8472
 bit_wait_io+0xe/0xc0 kernel/sched/wait_bit.c:209
 __wait_on_bit_lock+0xbf/0x1a0 kernel/sched/wait_bit.c:90
 out_of_line_wait_on_bit_lock+0x1d0/0x250 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 include/linux/buffer_head.h:402 [inline]
 __sync_dirty_buffer+0x120/0x380 fs/buffer.c:3144
 __ext4_handle_dirty_metadata+0x288/0x800 fs/ext4/ext4_jbd2.c:381
 ext4_convert_inline_data_nolock+0xad1/0xda0 fs/ext4/inline.c:1262
 ext4_convert_inline_data+0x4cf/0x610 fs/ext4/inline.c:2045
 ext4_fallocate+0x148/0x20c0 fs/ext4/extents.c:4705
 vfs_fallocate+0x54a/0x6b0 fs/open.c:308
 do_vfs_ioctl+0x2317/0x2b70 fs/ioctl.c:853
 __do_sys_ioctl fs/ioctl.c:872 [inline]
 __se_sys_ioctl+0x81/0x160 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f172182f169
RSP: 002b:00007f171fda1168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f172194ef80 RCX: 00007f172182f169
RDX: 0000000020000000 RSI: 0000000040305839 RDI: 0000000000000004
RBP: 00007f172188aca1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff358878ff R14: 00007f171fda1300 R15: 0000000000022000
 </TASK>
INFO: task syz-executor.5:11248 blocked for more than 143 seconds.
      Not tainted 5.15.111-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.5  state:D stack:24288 pid:11248 ppid:  3555 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5026 [inline]
 __schedule+0x12c4/0x4590 kernel/sched/core.c:6372
 schedule+0x11b/0x1f0 kernel/sched/core.c:6455
 io_schedule+0x88/0x100 kernel/sched/core.c:8472
 bit_wait_io+0xe/0xc0 kernel/sched/wait_bit.c:209
 __wait_on_bit_lock+0xbf/0x1a0 kernel/sched/wait_bit.c:90
 out_of_line_wait_on_bit_lock+0x1d0/0x250 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 include/linux/buffer_head.h:402 [inline]
 __sync_dirty_buffer+0x120/0x380 fs/buffer.c:3144
 __ext4_handle_dirty_metadata+0x288/0x800 fs/ext4/ext4_jbd2.c:381
 ext4_convert_inline_data_nolock+0xad1/0xda0 fs/ext4/inline.c:1262
 ext4_convert_inline_data+0x4cf/0x610 fs/ext4/inline.c:2045
 ext4_fallocate+0x148/0x20c0 fs/ext4/extents.c:4705
 vfs_fallocate+0x54a/0x6b0 fs/open.c:308
 do_vfs_ioctl+0x2317/0x2b70 fs/ioctl.c:853
 __do_sys_ioctl fs/ioctl.c:872 [inline]
 __se_sys_ioctl+0x81/0x160 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7fa63aa8b169
RSP: 002b:00007fa638ffd168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fa63abaaf80 RCX: 00007fa63aa8b169
RDX: 0000000020000000 RSI: 0000000040305829 RDI: 0000000000000004
RBP: 00007fa63aae6ca1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff5c9261df R14: 00007fa638ffd300 R15: 0000000000022000
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c91c5a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by kworker/u4:1/144:
2 locks held by getty/3261:
 #0: ffff88814a64f098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc900022a32e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1da0 drivers/tty/n_tty.c:2147
1 lock held by syz-fuzzer/3538:
3 locks held by kworker/u4:7/3897:
 #0: ffff88801419c938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2280
 #1: ffffc90004d67d20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2282
 #2: ffff888011e620e0 (&type->s_umount_key#41){.+.+}-{3:3}, at: trylock_super+0x1b/0xf0 fs/super.c:418
3 locks held by syz-executor.2/11220:
 #0: ffff8880219cc460 (sb_writers#5){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2966 [inline]
 #0: ffff8880219cc460 (sb_writers#5){.+.+}-{0:0}, at: vfs_fallocate+0x4bd/0x6b0 fs/open.c:307
 #1: ffff88803b7e17e0 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
 #1: ffff88803b7e17e0 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: ext4_fallocate+0x140/0x20c0 fs/ext4/extents.c:4704
 #2: ffff88803b7e14b8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_lock_xattr fs/ext4/xattr.h:155 [inline]
 #2: ffff88803b7e14b8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_convert_inline_data+0x3ab/0x610 fs/ext4/inline.c:2043
3 locks held by syz-executor.5/11248:
 #0: ffff8880381f8460 (sb_writers#5){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2966 [inline]
 #0: ffff8880381f8460 (sb_writers#5){.+.+}-{0:0}, at: vfs_fallocate+0x4bd/0x6b0 fs/open.c:307
 #1: ffff888098582bd0 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
 #1: ffff888098582bd0 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: ext4_fallocate+0x140/0x20c0 fs/ext4/extents.c:4704
 #2: ffff8880985828a8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_lock_xattr fs/ext4/xattr.h:155 [inline]
 #2: ffff8880985828a8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_convert_inline_data+0x3ab/0x610 fs/ext4/inline.c:2043
1 lock held by syz-executor.5/11326:
 #0: ffff88801becc118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x14d/0xa50 block/bdev.c:817
1 lock held by syz-executor.2/11885:
 #0: ffff88801becc118 (&disk->open_mutex){+.+.}-{3:3}, at: sync_bdevs+0x1a5/0x310 block/bdev.c:1050

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

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.111-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/28/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline]
 watchdog+0xe72/0xeb0 kernel/hung_task.c:295
 kthread+0x3f6/0x4f0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt drivers/acpi/processor_idle.c:109 [inline]
NMI backtrace for cpu 1 skipped: idling at acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:570

Crashes (10):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/05/15 23:27 linux-5.15.y b0ece631f84a c4d362e7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in __sync_dirty_buffer
2023/05/13 14:52 linux-5.15.y b0ece631f84a 2b9ba477 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in __sync_dirty_buffer
2023/05/12 20:40 linux-5.15.y b0ece631f84a ecca8a24 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in __sync_dirty_buffer
2023/05/12 00:32 linux-5.15.y b0ece631f84a adb9a3cd .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in __sync_dirty_buffer
2023/05/10 13:58 linux-5.15.y 8a7f2a5c5aa1 14b12a99 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in __sync_dirty_buffer
2023/05/10 01:51 linux-5.15.y 8a7f2a5c5aa1 30aa2a7e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in __sync_dirty_buffer
2023/05/02 01:24 linux-5.15.y 8a7f2a5c5aa1 62df2017 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in __sync_dirty_buffer
2023/04/23 22:05 linux-5.15.y 3299fb36854f 2b32bd34 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in __sync_dirty_buffer
2023/04/22 16:47 linux-5.15.y 3299fb36854f 2b32bd34 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in __sync_dirty_buffer
2023/04/08 18:56 linux-5.15.y d86dfc4d95cd 71147e29 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in __sync_dirty_buffer
* Struck through repros no longer work on HEAD.