syzbot


INFO: task hung in nilfs_segctor_thread

Status: fixed on 2023/06/08 14:41
Subsystems: nilfs
[Documentation on labels]
Reported-by: syzbot+f0c4082ce5ebebdac63b@syzkaller.appspotmail.com
Fix commit: 99b9402a36f0 nilfs2: fix underflow in second superblock position calculations
First crash: 513d, last: 303d
Cause bisection: failed (error log, bisect log)
  
Discussions (2)
Title Replies (including bot) Last reply
[syzbot] INFO: task hung in nilfs_segctor_thread 4 (6) 2023/02/15 08:52
[PATCH] nilfs2: fix underflow in second superblock position calculations 1 (1) 2023/02/14 22:40
Similar bugs (4)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 INFO: task hung in nilfs_segctor_thread nilfs2 C 41 380d 482d 0/1 upstream: reported C repro on 2022/11/05 03:06
linux-5.15 INFO: task hung in nilfs_segctor_thread 3 314d 326d 0/3 auto-obsoleted due to no activity on 2023/08/20 05:29
linux-4.14 INFO: task hung in nilfs_segctor_thread nilfs2 C 1 379d 379d 0/1 upstream: reported C repro on 2023/02/16 07:03
upstream INFO: task hung in nilfs_segctor_thread (2) nilfs 2 7d02h 11d 0/26 upstream: reported on 2024/02/19 10:54

Sample crash report:
INFO: task segctord:5067 blocked for more than 143 seconds.
      Not tainted 6.2.0-rc8-syzkaller-00015-gf6feea56f66d #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:segctord        state:D stack:23456 pid:5067  ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5293 [inline]
 __schedule+0x1409/0x43f0 kernel/sched/core.c:6606
 schedule+0xc3/0x190 kernel/sched/core.c:6682
 rwsem_down_write_slowpath+0xfcf/0x14a0 kernel/locking/rwsem.c:1190
 nilfs_transaction_lock+0x25c/0x4f0 fs/nilfs2/segment.c:357
 nilfs_segctor_thread_construct fs/nilfs2/segment.c:2486 [inline]
 nilfs_segctor_thread+0x52f/0x1140 fs/nilfs2/segment.c:2570
 kthread+0x270/0x300 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
 #0: ffffffff8cf258d0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x26/0xce0 kernel/rcu/tasks.h:507
1 lock held by rcu_tasks_trace/13:
 #0: ffffffff8cf260d0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x26/0xce0 kernel/rcu/tasks.h:507
1 lock held by khungtaskd/28:
 #0: ffffffff8cf25700 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by getty/4745:
 #0: ffff88802c2eb098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:244
 #1: ffffc900015b02f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6ab/0x1db0 drivers/tty/n_tty.c:2177
3 locks held by syz-executor996/5065:
1 lock held by segctord/5067:
 #0: ffff888017ce92a0 (&nilfs->ns_segctor_sem){++++}-{3:3}, at: nilfs_transaction_lock+0x25c/0x4f0 fs/nilfs2/segment.c:357

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

NMI backtrace for cpu 1
CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.2.0-rc8-syzkaller-00015-gf6feea56f66d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x4e5/0x560 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x1b4/0x3f0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
 watchdog+0xf70/0xfb0 kernel/hung_task.c:377
 kthread+0x270/0x300 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 5065 Comm: syz-executor996 Not tainted 6.2.0-rc8-syzkaller-00015-gf6feea56f66d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023
RIP: 0010:__lock_release kernel/locking/lockdep.c:5372 [inline]
RIP: 0010:lock_release+0x333/0xaa0 kernel/locking/lockdep.c:5688
Code: 00 f0 ff 42 0f b6 04 3b 84 c0 0f 85 7e 05 00 00 45 89 2e 41 81 fd ff ff 0f 00 0f 87 ff 02 00 00 48 8b 44 24 40 42 0f b6 04 38 <84> c0 0f 85 34 05 00 00 89 16 4c 89 e0 48 c1 e8 03 42 80 3c 38 00
RSP: 0018:ffffc90003def1c0 EFLAGS: 00000087
RAX: 0000000000000000 RBX: 1ffff11004d808aa RCX: ffffc90003def203
RDX: 0000000000000003 RSI: ffff888026c044b0 RDI: ffff888026c04530
RBP: ffffc90003def2f0 R08: dffffc0000000000 R09: fffffbfff1ca4ece
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff888026c04530
R13: 0000000000020021 R14: ffff888026c04550 R15: dffffc0000000000
FS:  0000555556f2e300(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000056435c9b6680 CR3: 000000001e10a000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 folio_mark_accessed+0x51c/0xf00 mm/swap.c:515
 __nilfs_get_page_block fs/nilfs2/page.c:42 [inline]
 nilfs_grab_buffer+0x3d3/0x540 fs/nilfs2/page.c:61
 nilfs_mdt_submit_block+0xd7/0x8f0 fs/nilfs2/mdt.c:121
 nilfs_mdt_read_block+0xeb/0x430 fs/nilfs2/mdt.c:176
 nilfs_mdt_get_block+0x12d/0xbb0 fs/nilfs2/mdt.c:251
 nilfs_sufile_get_segment_usage_block fs/nilfs2/sufile.c:92 [inline]
 nilfs_sufile_truncate_range fs/nilfs2/sufile.c:679 [inline]
 nilfs_sufile_resize+0x7a3/0x12b0 fs/nilfs2/sufile.c:777
 nilfs_resize_fs+0x20c/0xed0 fs/nilfs2/super.c:422
 nilfs_ioctl_resize fs/nilfs2/ioctl.c:1033 [inline]
 nilfs_ioctl+0x137c/0x2440 fs/nilfs2/ioctl.c:1301
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fada4f355f9
Code: Unable to access opcode bytes at 0x7fada4f355cf.
RSP: 002b:00007ffdc80a3908 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fada4f355f9
RDX: 0000000020000040 RSI: 0000000040086e8b RDI: 0000000000000006
RBP: 0000000000000000 R08: 00007fada4fa3ec0 R09: 00007fada4fa3ec0
R10: 00007fada4fa3ec0 R11: 0000000000000246 R12: 00007ffdc80a3930
R13: 0000000000000000 R14: 431bde82d7b634db R15: 0000000000000000
 </TASK>
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.549 msecs

Crashes (94):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/02/14 08:13 upstream f6feea56f66d 93ae7e0a .config strace log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs INFO: task hung in nilfs_segctor_thread
2023/05/02 21:05 upstream 865fdb08197e 52d40fd2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in nilfs_segctor_thread
2023/04/30 03:08 upstream 1ae78a14516b 62df2017 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in nilfs_segctor_thread
2023/04/29 23:16 upstream 1ae78a14516b 62df2017 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in nilfs_segctor_thread
2023/04/29 18:47 upstream 89d77f71f493 62df2017 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in nilfs_segctor_thread
2023/04/29 13:26 upstream 89d77f71f493 62df2017 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in nilfs_segctor_thread
2023/04/27 23:35 upstream 6e98b09da931 6f3d6fa7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in nilfs_segctor_thread
2023/04/27 17:51 upstream 6e98b09da931 6f3d6fa7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in nilfs_segctor_thread
2023/04/27 09:51 upstream 5c7ecada25d2 19a3dabe .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in nilfs_segctor_thread
2023/04/26 01:01 upstream 173ea743bf7a 65320f8e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in nilfs_segctor_thread
2023/04/24 13:48 upstream 457391b03803 fdc18293 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in nilfs_segctor_thread
2023/04/24 09:03 upstream 457391b03803 2b32bd34 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in nilfs_segctor_thread
2023/04/24 04:30 upstream 457391b03803 2b32bd34 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in nilfs_segctor_thread
2023/04/23 01:41 upstream 2caeeb9d4a1b 2b32bd34 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in nilfs_segctor_thread
2023/04/22 15:03 upstream 8e41e0a57566 2b32bd34 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in nilfs_segctor_thread
2023/04/20 16:01 upstream cb0856346a60 a219f34e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in nilfs_segctor_thread
2023/04/13 23:50 upstream de4664485abb 3cfcaa1b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in nilfs_segctor_thread
2023/04/13 19:18 upstream de4664485abb 3cfcaa1b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in nilfs_segctor_thread
2023/04/12 05:57 upstream e62252bc55b6 49faf98d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in nilfs_segctor_thread
2023/04/12 02:13 upstream e62252bc55b6 49faf98d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in nilfs_segctor_thread
2023/04/10 09:37 upstream 09a9639e56c0 71147e29 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in nilfs_segctor_thread
2023/04/05 11:14 upstream 76f598ba7d8e 831373d3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in nilfs_segctor_thread
2023/04/04 07:00 upstream 148341f0a2f5 41147e3e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in nilfs_segctor_thread
2023/04/03 03:18 upstream 6ab608fe852b f325deb0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in nilfs_segctor_thread
2023/04/01 18:52 upstream 7b50567bdcad f325deb0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in nilfs_segctor_thread
2023/03/22 02:14 upstream 2faac9a98f01 8b4eb097 .config console log report info ci2-upstream-fs INFO: task hung in nilfs_segctor_thread
2023/03/20 04:40 upstream e8d018dd0257 7939252e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in nilfs_segctor_thread
2023/03/17 13:54 upstream 0ddc84d2dd43 18b58603 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in nilfs_segctor_thread
2023/03/02 09:08 upstream ee3f96b16468 f8902b57 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in nilfs_segctor_thread
2023/02/26 14:41 upstream 2fcd07b7ccd5 ee50e71c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in nilfs_segctor_thread
2023/02/22 22:16 upstream 5b7c4cabbb65 409945bc .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in nilfs_segctor_thread
2023/02/14 05:28 upstream f6feea56f66d 93ae7e0a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in nilfs_segctor_thread
2023/02/07 16:12 upstream 05ecb680708a 5bc3be51 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in nilfs_segctor_thread
2023/01/31 17:26 upstream 22b8077d0fce b68fb8d6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in nilfs_segctor_thread
2023/01/25 04:46 upstream fb6e71db53f3 9dfcf09c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in nilfs_segctor_thread
2023/01/15 23:11 upstream 7c6984405241 a63719e7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in nilfs_segctor_thread
2023/01/09 22:39 upstream 1fe4fd6f5cad 1dac8c7a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in nilfs_segctor_thread
2023/01/09 13:10 upstream 1fe4fd6f5cad 1dac8c7a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in nilfs_segctor_thread
2023/01/05 18:01 upstream 41c03ba9beea 1dac8c7a .config console log report info ci-upstream-kasan-gce-selinux-root INFO: task hung in nilfs_segctor_thread
2023/01/05 03:53 upstream 512dee0c00ad 1dac8c7a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in nilfs_segctor_thread
2023/01/04 11:06 upstream 69b41ac87e4a 1dac8c7a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in nilfs_segctor_thread
2023/01/01 13:58 upstream e4cf7c25bae5 ab32d508 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in nilfs_segctor_thread
2022/11/29 10:06 upstream ca57f02295f1 ca9683b8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in nilfs_segctor_thread
2022/11/07 10:34 upstream 089d1c31224e 6d752409 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in nilfs_segctor_thread
2022/11/05 11:04 upstream 10d916c86eca 6d752409 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in nilfs_segctor_thread
2023/04/20 04:25 linux-next 3cdbc01c40e3 a219f34e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in nilfs_segctor_thread
2023/02/16 07:10 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 2d3827b3f393 6be0f1f5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 INFO: task hung in nilfs_segctor_thread
2023/01/23 22:51 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci edb2f0dc90f2 9dfcf09c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 INFO: task hung in nilfs_segctor_thread
2022/12/23 06:18 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci a5541c0811a0 9da18ae8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 INFO: task hung in nilfs_segctor_thread
2022/11/14 16:03 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 1621b6eaebf7 943f4cb8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 INFO: task hung in nilfs_segctor_thread
2022/11/07 14:16 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci f0c4d9fc9cc9 a779b11a .config console log report info ci-upstream-gce-arm64 INFO: task hung in nilfs_segctor_thread
2022/11/07 01:56 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci bbed346d5a96 6d752409 .config console log report info [disk image] [vmlinux] ci-upstream-gce-arm64 INFO: task hung in nilfs_segctor_thread
2022/10/05 07:56 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci bbed346d5a96 eab8f949 .config console log report info [disk image] [vmlinux] ci-upstream-gce-arm64 INFO: task hung in nilfs_segctor_thread
* Struck through repros no longer work on HEAD.