syzbot


INFO: task hung in f2fs_issue_checkpoint (2)

Status: upstream: reported C repro on 2025/07/04 10:07
Subsystems: f2fs
[Documentation on labels]
Reported-by: syzbot+8a7eea50810efde15b0a@syzkaller.appspotmail.com
First crash: 450d, last: 15h50m
Cause bisection: the cause commit could be any of (bisect log):
  2aac2538a97d f2fs: do sanity check on xattr node footer in f2fs_get_xnode_page()
  1788971e0bfa f2fs: introduce FAULT_INCONSISTENT_FOOTER
  1cf6b5670af1 f2fs: do sanity check on inode footer in f2fs_get_inode_page()
  986c50f6bca1 f2fs: fix to avoid accessing uninitialized curseg
  c2ecba026586 f2fs: control nat_bits feature via mount option
  19426c4988aa Revert "f2fs: rebuild nat_bits during umount"
  
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [f2fs?] INFO: task hung in f2fs_issue_checkpoint (2) 0 (2) 2025/07/15 07:45
Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in f2fs_issue_checkpoint f2fs 1 C error inconclusive 86 608d 988d 0/29 auto-obsoleted due to no activity on 2024/02/10 19:41
linux-6.1 INFO: task hung in f2fs_issue_checkpoint 1 6 267d 374d 0/3 auto-obsoleted due to no activity on 2025/01/29 10:18
linux-5.15 INFO: task hung in f2fs_issue_checkpoint (2) 1 1 337d 337d 0/3 auto-obsoleted due to no activity on 2024/11/20 23:40
linux-5.15 INFO: task hung in f2fs_issue_checkpoint 1 3 442d 469d 0/3 auto-obsoleted due to no activity on 2024/08/07 22:27

Sample crash report:
INFO: task syz-executor288:5860 blocked for more than 143 seconds.
      Not tainted 6.16.0-rc6-next-20250714-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor288 state:D stack:24648 pid:5860  tgid:5860  ppid:5859   task_flags:0x400140 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5314 [inline]
 __schedule+0x16f5/0x4d00 kernel/sched/core.c:6697
 __schedule_loop kernel/sched/core.c:6775 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6790
 schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75
 do_wait_for_common kernel/sched/completion.c:100 [inline]
 __wait_for_common kernel/sched/completion.c:121 [inline]
 wait_for_common kernel/sched/completion.c:132 [inline]
 wait_for_completion+0x2bf/0x5d0 kernel/sched/completion.c:153
 f2fs_issue_checkpoint+0x376/0x570 fs/f2fs/checkpoint.c:-1
 f2fs_do_sync_file+0x869/0x1860 fs/f2fs/file.c:346
 generic_write_sync include/linux/fs.h:3038 [inline]
 f2fs_file_write_iter+0x74d/0x2410 fs/f2fs/file.c:5252
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x548/0xa90 fs/read_write.c:686
 ksys_pwrite64 fs/read_write.c:793 [inline]
 __do_sys_pwrite64 fs/read_write.c:801 [inline]
 __se_sys_pwrite64 fs/read_write.c:798 [inline]
 __x64_sys_pwrite64+0x193/0x220 fs/read_write.c:798
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9b43976b19
RSP: 002b:00007ffee8c2a118 EFLAGS: 00000246 ORIG_RAX: 0000000000000012
RAX: ffffffffffffffda RBX: 0000200000000040 RCX: 00007f9b43976b19
RDX: 000000000000fdef RSI: 0000200000000140 RDI: 0000000000000004
RBP: 0031656c69662f2e R08: 0000555559c514c0 R09: 0000555559c514c0
R10: 0000000000000e7c R11: 0000000000000246 R12: 00007ffee8c2a140
R13: 00007ffee8c2a368 R14: 431bde82d7b634db R15: 00007f9b439bf03b
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8e13eca0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e13eca0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8e13eca0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
3 locks held by kworker/u8:6/1102:
 #0: ffff8881404f4948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #0: ffff8881404f4948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3322
 #1: ffffc90003c6fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3215 [inline]
 #1: ffffc90003c6fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3322
 #2: ffff8880292d40e0 (&type->s_umount_key#42){.+.+}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563
2 locks held by getty/5605:
 #0: ffff88803009b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
1 lock held by syz-executor288/5860:
 #0: ffff8880292d4428 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3103 [inline]
 #0: ffff8880292d4428 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x211/0xa90 fs/read_write.c:682
2 locks held by f2fs_ckpt-7:0/5861:

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc6-next-20250714-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline]
 watchdog+0xfee/0x1030 kernel/hung_task.c:491
 kthread+0x70e/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 5861 Comm: f2fs_ckpt-7:0 Not tainted 6.16.0-rc6-next-20250714-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:xa_entry include/linux/xarray.h:1226 [inline]
RIP: 0010:xas_reload+0x19a/0x470 include/linux/xarray.h:1630
Code: ff e8 ba 15 7f 09 89 c5 31 ff 89 c6 e8 1f a4 c7 ff 85 ed 0f 84 14 01 00 00 e8 d2 9f c7 ff e9 5a 02 00 00 e8 c8 9f c7 ff eb 1d <e8> 31 53 ad ff 89 c5 31 ff 89 c6 e8 f6 a3 c7 ff 85 ed 0f 84 27 01
RSP: 0018:ffffc9000414f528 EFLAGS: 00000246
RAX: ffffffff81f82547 RBX: ffffea0001c272c0 RCX: 0000000000000000
RDX: ffff8880792bbc00 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffea0001c272f7 R09: 1ffffd4000384e5e
R10: dffffc0000000000 R11: fffff94000384e5f R12: ffff888075e30240
R13: 1ffff92000829eb0 R14: ffffc9000414f580 R15: ffff888025979e40
FS:  0000000000000000(0000) GS:ffff888125bed000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe4c0415fb3 CR3: 000000000df38000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 filemap_get_entry+0x1c4/0x2f0 mm/filemap.c:1884
 __filemap_get_folio+0x68/0xaf0 mm/filemap.c:1916
 f2fs_grab_cache_folio+0x2b/0x380 fs/f2fs/f2fs.h:2870
 __get_node_folio+0x194/0x1410 fs/f2fs/node.c:1505
 f2fs_update_inode_page+0x82/0x190 fs/f2fs/inode.c:766
 f2fs_sync_inode_meta fs/f2fs/checkpoint.c:1156 [inline]
 block_operations fs/f2fs/checkpoint.c:1263 [inline]
 f2fs_write_checkpoint+0xb6e/0x1df0 fs/f2fs/checkpoint.c:1638
 __write_checkpoint_sync fs/f2fs/checkpoint.c:1756 [inline]
 __checkpoint_and_complete_reqs+0xd9/0x3b0 fs/f2fs/checkpoint.c:1775
 issue_checkpoint_thread+0xd9/0x260 fs/f2fs/checkpoint.c:1806
 kthread+0x70e/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Crashes (41):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/07/15 07:44 linux-next 0be23810e32e 03fcfc4b .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci-upstream-linux-next-kasan-gce-root INFO: task hung in f2fs_issue_checkpoint
2025/07/15 08:18 upstream 155a3c003e55 03fcfc4b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in f2fs_issue_checkpoint
2025/07/11 01:00 upstream bc9ff192a6c9 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in f2fs_issue_checkpoint
2025/07/10 00:44 upstream 733923397fd9 f4e5e155 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in f2fs_issue_checkpoint
2025/07/09 17:19 upstream 733923397fd9 f4e5e155 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in f2fs_issue_checkpoint
2025/07/09 04:47 upstream d006330be3f7 4d9fdfa4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in f2fs_issue_checkpoint
2025/07/06 16:45 upstream 1f988d0788f5 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in f2fs_issue_checkpoint
2025/07/01 18:34 upstream 66701750d556 091a06cd .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in f2fs_issue_checkpoint
2025/06/30 10:24 upstream d0b3b7b22dfa fc9d8ee5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in f2fs_issue_checkpoint
2025/06/30 09:52 upstream d0b3b7b22dfa fc9d8ee5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in f2fs_issue_checkpoint
2025/06/30 09:10 upstream d0b3b7b22dfa fc9d8ee5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in f2fs_issue_checkpoint
2025/06/30 03:30 upstream afa9a6f4f574 fc9d8ee5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in f2fs_issue_checkpoint
2025/06/29 05:52 upstream dfba48a70cb6 fc9d8ee5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in f2fs_issue_checkpoint
2025/06/26 03:22 upstream 92ca6c498a5e 26d77996 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in f2fs_issue_checkpoint
2025/06/25 22:27 upstream 92ca6c498a5e 26d77996 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in f2fs_issue_checkpoint
2025/06/14 19:45 upstream 4774cfe3543a 5f4b362d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in f2fs_issue_checkpoint
2025/06/14 11:10 upstream 02adc1490e6d 0e8da31f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in f2fs_issue_checkpoint
2025/05/26 02:06 upstream 0f8c0258bf04 2d4582d0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in f2fs_issue_checkpoint
2025/05/24 14:49 upstream 4856ebd99715 ed351ea7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in f2fs_issue_checkpoint
2025/05/14 19:18 upstream 1a80a098c606 a4fa04ef .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in f2fs_issue_checkpoint
2025/05/11 11:48 upstream 3ce9925823c7 77908e5f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in f2fs_issue_checkpoint
2025/05/08 11:17 upstream d76bb1ebb558 dbf35fa1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in f2fs_issue_checkpoint
2025/04/30 11:52 upstream b6ea1680d0ac 85a5a23f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in f2fs_issue_checkpoint
2025/04/24 11:10 upstream a79be02bba5c 9882047a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in f2fs_issue_checkpoint
2025/03/18 08:06 upstream fc444ada1310 ce3352cd .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in f2fs_issue_checkpoint
2024/12/28 18:54 upstream fd0584d220fe d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in f2fs_issue_checkpoint
2024/10/22 22:33 upstream c2ee9f594da8 a93682b3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in f2fs_issue_checkpoint
2024/10/22 01:53 upstream d12937763990 f1e4447c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in f2fs_issue_checkpoint
2024/10/22 01:13 upstream d12937763990 f1e4447c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in f2fs_issue_checkpoint
2024/10/02 00:23 upstream e32cde8d2bd7 ea2b66a6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in f2fs_issue_checkpoint
2024/09/17 20:25 upstream 2f27fce67173 c673ca06 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in f2fs_issue_checkpoint
2024/09/11 14:47 upstream 8d8d276ba2fb 8ab55d0e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in f2fs_issue_checkpoint
2024/09/09 16:28 upstream da3ea35007d0 073f8be2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in f2fs_issue_checkpoint
2024/09/09 16:19 upstream da3ea35007d0 073f8be2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in f2fs_issue_checkpoint
2024/08/10 10:15 upstream afdab700f65e 6f4edef4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in f2fs_issue_checkpoint
2024/07/07 14:55 upstream c6653f49e4fd 2a40360c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in f2fs_issue_checkpoint
2024/07/07 14:54 upstream c6653f49e4fd 2a40360c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in f2fs_issue_checkpoint
2024/04/21 03:58 upstream 977b1ef51866 af24b050 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in f2fs_issue_checkpoint
2025/07/15 04:38 linux-next 0be23810e32e 03fcfc4b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in f2fs_issue_checkpoint
2025/07/15 04:37 linux-next 0be23810e32e 03fcfc4b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in f2fs_issue_checkpoint
2025/06/14 21:28 linux-next bc6e0ba6c9ba 5f4b362d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in f2fs_issue_checkpoint
* Struck through repros no longer work on HEAD.