syzbot


INFO: task hung in freeze_super (6)

Status: upstream: reported C repro on 2025/05/21 06:35
Subsystems: f2fs
[Documentation on labels]
Reported-by: syzbot+aa5bb5f6860e08a60450@syzkaller.appspotmail.com
First crash: 6d14h, last: 5d13h
Cause bisection: introduced by (bisect log) :
commit 84b5bb8bf0f6a78c232a20c2eecdbb8112ac2703
Author: Qi Han <hanqi@vivo.com>
Date: Fri Oct 25 09:18:23 2024 +0000

  f2fs: modify f2fs_is_checkpoint_ready logic to allow more data to be written with the CP disable

Crash: INFO: rcu detected stall in corrupted (log)
Repro: C syz .config
  
Discussions (4)
Title Replies (including bot) Last reply
[PATCH v3] f2fs: fix to skip f2fs_balance_fs() if checkpoint is disabled 2 (2) 2025/05/23 03:35
[PATCH v2] f2fs: fix to skip f2fs_balance_fs() if checkpoint is disabled 3 (3) 2025/05/23 02:32
[syzbot] [f2fs?] INFO: task hung in freeze_super (6) 1 (3) 2025/05/21 14:10
[PATCH] f2fs: fix to skip f2fs_balance_fs() if checkpoint is disabled 1 (1) 2025/05/21 11:41
Similar bugs (6)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 INFO: task hung in freeze_super origin:upstream missing-backport C error 15 3d12h 285d 0/3 upstream: reported C repro on 2024/08/10 19:01
upstream INFO: task hung in freeze_super (3) gfs2 C error 19 735d 896d 22/28 fixed on 2023/06/08 14:41
upstream INFO: task hung in freeze_super (5) f2fs 1 151d 151d 0/28 auto-obsoleted due to no activity on 2025/03/23 05:38
upstream INFO: task hung in freeze_super gfs2 348 1510d 1586d 0/28 auto-closed as invalid on 2021/07/02 19:19
upstream INFO: task hung in freeze_super (2) gfs2 1 1419d 1419d 0/28 auto-closed as invalid on 2021/10/01 20:27
upstream INFO: task hung in freeze_super (4) gfs2 1 691d 691d 0/28 auto-obsoleted due to no activity on 2023/09/30 13:36
Last patch testing requests (1)
Created Duration User Patch Repo Result
2025/05/21 11:40 2h28m chao@kernel.org https://git.kernel.org/pub/scm/linux/kernel/git/chao/linux.git bugfix/syzbot report log

Sample crash report:
INFO: task syz-executor328:5836 blocked for more than 143 seconds.
      Not tainted 6.15.0-rc6-syzkaller-00208-g3c21441eeffc #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor328 state:D stack:23432 pid:5836  tgid:5832  ppid:5826   task_flags:0x400140 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x168f/0x4c70 kernel/sched/core.c:6767
 __schedule_loop kernel/sched/core.c:6845 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6860
 percpu_down_write+0x28e/0x330 kernel/locking/percpu-rwsem.c:253
 sb_wait_write fs/super.c:1855 [inline]
 freeze_super+0x4c2/0xeb0 fs/super.c:2044
 fs_bdev_freeze+0x19f/0x310 fs/super.c:1484
 bdev_freeze+0xd8/0x220 block/bdev.c:298
 f2fs_do_shutdown+0x23d/0x5c0 fs/f2fs/file.c:2367
 f2fs_ioc_shutdown fs/f2fs/file.c:2459 [inline]
 __f2fs_ioctl+0x3de9/0xae80 fs/f2fs/file.c:4558
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:906 [inline]
 __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:892
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f836b5ab109
RSP: 002b:00007f836b55f218 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f836b6386c8 RCX: 00007f836b5ab109
RDX: 0000200000000080 RSI: 000000008004587d RDI: 0000000000000005
RBP: 00007f836b6386c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f836b604668
R13: 00002000000000c0 R14: 0000200000000180 R15: 00002000000000e0
 </TASK>
INFO: task syz-executor328:5856 blocked for more than 144 seconds.
      Not tainted 6.15.0-rc6-syzkaller-00208-g3c21441eeffc #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor328 state:D stack:24392 pid:5856  tgid:5832  ppid:5826   task_flags:0x400040 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x168f/0x4c70 kernel/sched/core.c:6767
 __schedule_loop kernel/sched/core.c:6845 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6860
 io_schedule+0x81/0xe0 kernel/sched/core.c:7742
 f2fs_balance_fs+0x4b4/0x780 fs/f2fs/segment.c:444
 f2fs_map_blocks+0x3af1/0x43b0 fs/f2fs/data.c:1791
 f2fs_expand_inode_data+0x653/0xaf0 fs/f2fs/file.c:1872
 f2fs_fallocate+0x4f5/0x990 fs/f2fs/file.c:1975
 vfs_fallocate+0x6a0/0x830 fs/open.c:338
 ioctl_preallocate fs/ioctl.c:290 [inline]
 file_ioctl fs/ioctl.c:-1 [inline]
 do_vfs_ioctl+0x1b8f/0x1eb0 fs/ioctl.c:885
 __do_sys_ioctl fs/ioctl.c:904 [inline]
 __se_sys_ioctl+0x82/0x170 fs/ioctl.c:892
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f836b5ab109
RSP: 002b:00007f836b53e218 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f836b6386d8 RCX: 00007f836b5ab109
RDX: 00002000000000c0 RSI: 0000000040305828 RDI: 0000000000000004
RBP: 00007f836b6386d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f836b604668
R13: 00002000000000c0 R14: 0000200000000180 R15: 00002000000000e0
 </TASK>
INFO: task syz-executor328:5894 blocked for more than 145 seconds.
      Not tainted 6.15.0-rc6-syzkaller-00208-g3c21441eeffc #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor328 state:D stack:24152 pid:5894  tgid:5892  ppid:5825   task_flags:0x400140 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x168f/0x4c70 kernel/sched/core.c:6767
 __schedule_loop kernel/sched/core.c:6845 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6860
 percpu_down_write+0x28e/0x330 kernel/locking/percpu-rwsem.c:253
 sb_wait_write fs/super.c:1855 [inline]
 freeze_super+0x4c2/0xeb0 fs/super.c:2044
 fs_bdev_freeze+0x19f/0x310 fs/super.c:1484
 bdev_freeze+0xd8/0x220 block/bdev.c:298
 f2fs_do_shutdown+0x23d/0x5c0 fs/f2fs/file.c:2367
 f2fs_ioc_shutdown fs/f2fs/file.c:2459 [inline]
 __f2fs_ioctl+0x3de9/0xae80 fs/f2fs/file.c:4558
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:906 [inline]
 __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:892
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f836b5ab109
RSP: 002b:00007f836b55f218 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f836b6386c8 RCX: 00007f836b5ab109
RDX: 0000200000000080 RSI: 000000008004587d RDI: 0000000000000005
RBP: 00007f836b6386c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f836b604668
R13: 00002000000000c0 R14: 0000200000000180 R15: 00002000000000e0
 </TASK>
INFO: task syz-executor328:5907 blocked for more than 145 seconds.
      Not tainted 6.15.0-rc6-syzkaller-00208-g3c21441eeffc #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor328 state:D stack:25432 pid:5907  tgid:5892  ppid:5825   task_flags:0x400040 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x168f/0x4c70 kernel/sched/core.c:6767
 __schedule_loop kernel/sched/core.c:6845 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6860
 io_schedule+0x81/0xe0 kernel/sched/core.c:7742
 f2fs_balance_fs+0x4b4/0x780 fs/f2fs/segment.c:444
 f2fs_map_blocks+0x3af1/0x43b0 fs/f2fs/data.c:1791
 f2fs_expand_inode_data+0x653/0xaf0 fs/f2fs/file.c:1872
 f2fs_fallocate+0x4f5/0x990 fs/f2fs/file.c:1975
 vfs_fallocate+0x6a0/0x830 fs/open.c:338
 ioctl_preallocate fs/ioctl.c:290 [inline]
 file_ioctl fs/ioctl.c:-1 [inline]
 do_vfs_ioctl+0x1b8f/0x1eb0 fs/ioctl.c:885
 __do_sys_ioctl fs/ioctl.c:904 [inline]
 __se_sys_ioctl+0x82/0x170 fs/ioctl.c:892
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f836b5ab109
RSP: 002b:00007f836b53e218 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f836b6386d8 RCX: 00007f836b5ab109
RDX: 00002000000000c0 RSI: 0000000040305828 RDI: 0000000000000004
RBP: 00007f836b6386d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f836b604668
R13: 00002000000000c0 R14: 0000200000000180 R15: 00002000000000e0
 </TASK>
INFO: task syz-executor328:5896 blocked for more than 147 seconds.
      Not tainted 6.15.0-rc6-syzkaller-00208-g3c21441eeffc #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor328 state:D stack:25144 pid:5896  tgid:5893  ppid:5827   task_flags:0x400140 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x168f/0x4c70 kernel/sched/core.c:6767
 __schedule_loop kernel/sched/core.c:6845 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6860
 percpu_down_write+0x28e/0x330 kernel/locking/percpu-rwsem.c:253
 sb_wait_write fs/super.c:1855 [inline]
 freeze_super+0x4c2/0xeb0 fs/super.c:2044
 fs_bdev_freeze+0x19f/0x310 fs/super.c:1484
 bdev_freeze+0xd8/0x220 block/bdev.c:298
 f2fs_do_shutdown+0x23d/0x5c0 fs/f2fs/file.c:2367
 f2fs_ioc_shutdown fs/f2fs/file.c:2459 [inline]
 __f2fs_ioctl+0x3de9/0xae80 fs/f2fs/file.c:4558
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:906 [inline]
 __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:892
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f836b5ab109
RSP: 002b:00007f836b55f218 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f836b6386c8 RCX: 00007f836b5ab109
RDX: 0000200000000080 RSI: 000000008004587d RDI: 0000000000000005
RBP: 00007f836b6386c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f836b604668
R13: 00002000000000c0 R14: 0000200000000180 R15: 00002000000000e0
 </TASK>
INFO: task syz-executor328:5908 blocked for more than 147 seconds.
      Not tainted 6.15.0-rc6-syzkaller-00208-g3c21441eeffc #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor328 state:D stack:24984 pid:5908  tgid:5893  ppid:5827   task_flags:0x400040 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x168f/0x4c70 kernel/sched/core.c:6767
 __schedule_loop kernel/sched/core.c:6845 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6860
 io_schedule+0x81/0xe0 kernel/sched/core.c:7742
 f2fs_balance_fs+0x4b4/0x780 fs/f2fs/segment.c:444
 f2fs_map_blocks+0x3af1/0x43b0 fs/f2fs/data.c:1791
 f2fs_expand_inode_data+0x653/0xaf0 fs/f2fs/file.c:1872
 f2fs_fallocate+0x4f5/0x990 fs/f2fs/file.c:1975
 vfs_fallocate+0x6a0/0x830 fs/open.c:338
 ioctl_preallocate fs/ioctl.c:290 [inline]
 file_ioctl fs/ioctl.c:-1 [inline]
 do_vfs_ioctl+0x1b8f/0x1eb0 fs/ioctl.c:885
 __do_sys_ioctl fs/ioctl.c:904 [inline]
 __se_sys_ioctl+0x82/0x170 fs/ioctl.c:892
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f836b5ab109
RSP: 002b:00007f836b53e218 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f836b6386d8 RCX: 00007f836b5ab109
RDX: 00002000000000c0 RSI: 0000000040305828 RDI: 0000000000000004
RBP: 00007f836b6386d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f836b604668
R13: 00002000000000c0 R14: 0000200000000180 R15: 00002000000000e0
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/u8:1/13:
 #0: ffff888143ad3148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #0: ffff888143ad3148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319
 #1: ffffc90000127c60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #1: ffffc90000127c60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319
 #2: ffff888079b0a0e0 (&type->s_umount_key#43){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:562
1 lock held by khungtaskd/31:
 #0: ffffffff8df3dce0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8df3dce0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8df3dce0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6764
5 locks held by kworker/u8:2/36:
3 locks held by kworker/u8:3/53:
 #0: ffff888143ad3148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #0: ffff888143ad3148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319
 #1: ffffc90000be7c60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #1: ffffc90000be7c60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319
 #2: ffff8880240c40e0 (&type->s_umount_key#43){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:562
3 locks held by kworker/u8:5/969:
 #0: ffff888143ad3148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #0: ffff888143ad3148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319
 #1: ffffc90003787c60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #1: ffffc90003787c60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319
 #2: ffff8880230a20e0 (&type->s_umount_key#43){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:562
2 locks held by getty/5576:
 #0: ffff888030c370a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900036e32f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
2 locks held by syz-executor328/5836:
 #0: ffff888022856930 (&bdev->bd_fsfreeze_mutex){+.+.}-{4:4}, at: bdev_freeze+0x2a/0x220 block/bdev.c:289
 #1: ffff8880230a2420 (sb_writers#9){++++}-{0:0}, at: sb_wait_write fs/super.c:1855 [inline]
 #1: ffff8880230a2420 (sb_writers#9){++++}-{0:0}, at: freeze_super+0x4c2/0xeb0 fs/super.c:2044
3 locks held by syz-executor328/5856:
 #0: ffff8880230a2420 (sb_writers#9){++++}-{0:0}, at: file_start_write include/linux/fs.h:3041 [inline]
 #0: ffff8880230a2420 (sb_writers#9){++++}-{0:0}, at: vfs_fallocate+0x62a/0x830 fs/open.c:337
 #1: ffff888078bcbfd8 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline]
 #1: ffff888078bcbfd8 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: f2fs_fallocate+0x24e/0x990 fs/f2fs/file.c:1940
 #2: ffff888033c5d4f8 (&sbi->pin_sem){+.+.}-{4:4}, at: f2fs_down_write fs/f2fs/f2fs.h:2213 [inline]
 #2: ffff888033c5d4f8 (&sbi->pin_sem){+.+.}-{4:4}, at: f2fs_expand_inode_data+0x430/0xaf0 fs/f2fs/file.c:1839
2 locks held by syz-executor328/5894:
 #0: ffff888022855db0 (&bdev->bd_fsfreeze_mutex){+.+.}-{4:4}, at: bdev_freeze+0x2a/0x220 block/bdev.c:289
 #1: ffff888079b0a420 (sb_writers#9){++++}-{0:0}, at: sb_wait_write fs/super.c:1855 [inline]
 #1: ffff888079b0a420 (sb_writers#9){++++}-{0:0}, at: freeze_super+0x4c2/0xeb0 fs/super.c:2044
3 locks held by syz-executor328/5907:
 #0: ffff888079b0a420 (sb_writers#9){++++}-{0:0}, at: file_start_write include/linux/fs.h:3041 [inline]
 #0: ffff888079b0a420 (sb_writers#9){++++}-{0:0}, at: vfs_fallocate+0x62a/0x830 fs/open.c:337
 #1: ffff888074156398 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline]
 #1: ffff888074156398 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: f2fs_fallocate+0x24e/0x990 fs/f2fs/file.c:1940
 #2: ffff888079f554f8 (&sbi->pin_sem){+.+.}-{4:4}, at: f2fs_down_write fs/f2fs/f2fs.h:2213 [inline]
 #2: ffff888079f554f8 (&sbi->pin_sem){+.+.}-{4:4}, at: f2fs_expand_inode_data+0x430/0xaf0 fs/f2fs/file.c:1839
2 locks held by syz-executor328/5896:
 #0: ffff8880228574b0 (&bdev->bd_fsfreeze_mutex){+.+.}-{4:4}, at: bdev_freeze+0x2a/0x220 block/bdev.c:289
 #1: ffff8880240c4420 (sb_writers#9){++++}-{0:0}, at: sb_wait_write fs/super.c:1855 [inline]
 #1: ffff8880240c4420 (sb_writers#9){++++}-{0:0}, at: freeze_super+0x4c2/0xeb0 fs/super.c:2044
3 locks held by syz-executor328/5908:
 #0: ffff8880240c4420 (sb_writers#9){++++}-{0:0}, at: file_start_write include/linux/fs.h:3041 [inline]
 #0: ffff8880240c4420 (sb_writers#9){++++}-{0:0}, at: vfs_fallocate+0x62a/0x830 fs/open.c:337
 #1: ffff888074157578 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline]
 #1: ffff888074157578 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: f2fs_fallocate+0x24e/0x990 fs/f2fs/file.c:1940
 #2: ffff88807f9ad4f8 (&sbi->pin_sem){+.+.}-{4:4}, at: f2fs_down_write fs/f2fs/f2fs.h:2213 [inline]
 #2: ffff88807f9ad4f8 (&sbi->pin_sem){+.+.}-{4:4}, at: f2fs_expand_inode_data+0x430/0xaf0 fs/f2fs/file.c:1839
2 locks held by syz-executor328/6364:
 #0: ffff8880228546b0 (&bdev->bd_fsfreeze_mutex){+.+.}-{4:4}, at: bdev_freeze+0x2a/0x220 block/bdev.c:289
 #1: ffff88807dedc420 (sb_writers#9){++++}-{0:0}, at: sb_wait_write fs/super.c:1855 [inline]
 #1: ffff88807dedc420 (sb_writers#9){++++}-{0:0}, at: freeze_super+0x4c2/0xeb0 fs/super.c:2044
3 locks held by syz-executor328/6374:
 #0: ffff88807dedc420 (sb_writers#9){++++}-{0:0}, at: file_start_write include/linux/fs.h:3041 [inline]
 #0: ffff88807dedc420 (sb_writers#9){++++}-{0:0}, at: vfs_fallocate+0x62a/0x830 fs/open.c:337
 #1: ffff88806d35a508 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline]
 #1: ffff88806d35a508 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: f2fs_fallocate+0x24e/0x990 fs/f2fs/file.c:1940
 #2: ffff888079e4d4f8 (&sbi->pin_sem){+.+.}-{4:4}, at: f2fs_down_write fs/f2fs/f2fs.h:2213 [inline]
 #2: ffff888079e4d4f8 (&sbi->pin_sem){+.+.}-{4:4}, at: f2fs_expand_inode_data+0x430/0xaf0 fs/f2fs/file.c:1839
2 locks held by syz-executor328/6379:
 #0: ffff888022855230 (&bdev->bd_fsfreeze_mutex){+.+.}-{4:4}, at: bdev_freeze+0x2a/0x220 block/bdev.c:289
 #1: ffff888033604420 (sb_writers#9){++++}-{0:0}, at: sb_wait_write fs/super.c:1855 [inline]
 #1: ffff888033604420 (sb_writers#9){++++}-{0:0}, at: freeze_super+0x4c2/0xeb0 fs/super.c:2044
3 locks held by syz-executor328/6382:
 #0: ffff888033604420 (sb_writers#9){++++}-{0:0}, at: file_start_write include/linux/fs.h:3041 [inline]
 #0: ffff888033604420 (sb_writers#9){++++}-{0:0}, at: vfs_fallocate+0x62a/0x830 fs/open.c:337
 #1: ffff88806d037578 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline]
 #1: ffff88806d037578 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: f2fs_fallocate+0x24e/0x990 fs/f2fs/file.c:1940
 #2: ffff8880286b14f8 (&sbi->pin_sem){+.+.}-{4:4}, at: f2fs_down_write fs/f2fs/f2fs.h:2213 [inline]
 #2: ffff8880286b14f8 (&sbi->pin_sem){+.+.}-{4:4}, at: f2fs_expand_inode_data+0x430/0xaf0 fs/f2fs/file.c:1839

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc6-syzkaller-00208-g3c21441eeffc #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:158 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline]
 watchdog+0xfee/0x1030 kernel/hung_task.c:437
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5905 Comm: f2fs_gc-7:4 Not tainted 6.15.0-rc6-syzkaller-00208-g3c21441eeffc #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:210
Code: 89 fb e8 23 00 00 00 48 8b 3d 5c c3 d5 0b 48 89 de 5b e9 33 41 55 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 48 8b 04 24 65 48 8b 0c 25 08 70 72 92 65 8b 15 18 7f
RSP: 0018:ffffc90004697b90 EFLAGS: 00000206
RAX: ffffffff818dcd2c RBX: ffff88802fa49e00 RCX: 0000000000000000
RDX: ffff88802fa49e00 RSI: 0000000000200000 RDI: 0000000000000000
RBP: 0000000000200000 R08: ffff88803342a007 R09: 1ffff11006685400
R10: dffffc0000000000 R11: ffffed1006685401 R12: ffff88807f9ac000
R13: dffffc0000000000 R14: ffff88802fa49e2c R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8881261f9000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f836b5fec18 CR3: 000000000dd38000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 to_kthread kernel/kthread.c:84 [inline]
 kthread_should_stop+0x59/0xf0 kernel/kthread.c:169
 gc_thread_func+0x344/0x2b30 fs/f2fs/gc.c:49
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/05/17 06:27 upstream 3c21441eeffc f41472b0 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-upstream-fs INFO: task hung in freeze_super
2025/05/18 02:57 upstream 5723cc3450bc f41472b0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in freeze_super
2025/05/17 02:01 upstream 3c21441eeffc f41472b0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in freeze_super
* Struck through repros no longer work on HEAD.