Hello,
syzbot has tested the proposed patch but the reproducer is still triggering an
issue:
INFO: task hung in f2fs_update_inode
INFO: task syz.2.18:6729 blocked for more than 143 seconds.
Not tainted 6.17.0-rc1-syzkaller-g5344e5bb8255 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.18 state:D stack:23736 pid:6729 tgid:6728 ppid:6450
task_flags:0x400140 flags:0x00004006
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1742/0x4c70 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7058
io_schedule+0x81/0xe0 kernel/sched/core.c:7903
folio_wait_bit_common+0x6b0/0xb90 mm/filemap.c:1317
folio_wait_writeback+0xb0/0x100 mm/page-writeback.c:3124
f2fs_folio_wait_writeback+0x16c/0x240 fs/f2fs/segment.c:4210
f2fs_update_inode+0x65/0x2620 fs/f2fs/inode.c:668
f2fs_update_inode_page+0x131/0x190 fs/f2fs/inode.c:783
f2fs_evict_inode+0xd4a/0x19c0 fs/f2fs/inode.c:936
evict+0x504/0x9c0 fs/inode.c:810
__dentry_kill+0x209/0x660 fs/dcache.c:669
dput+0x19f/0x2b0 fs/dcache.c:911
__fput+0x68e/0xa70 fs/file_table.c:476
task_work_run+0x1d1/0x260 kernel/task_work.c:227
get_signal+0x11c5/0x1310 kernel/signal.c:2807
arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f721d78e9a9
RSP: 002b:00007f721e541038 EFLAGS: 00000246 ORIG_RAX: 000000000000004b
RAX: fffffffffffffffb RBX: 00007f721d9b5fa0 RCX: 00007f721d78e9a9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000006
RBP: 00007f721d810d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f721d9b5fa0 R15: 00007ffe0a9ef388
</TASK>
INFO: task syz.1.17:6734 blocked for more than 144 seconds.
Not tainted 6.17.0-rc1-syzkaller-g5344e5bb8255 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.17 state:D stack:24136 pid:6734 tgid:6733 ppid:6439
task_flags:0x400140 flags:0x00004006
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1742/0x4c70 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7058
io_schedule+0x81/0xe0 kernel/sched/core.c:7903
folio_wait_bit_common+0x6b0/0xb90 mm/filemap.c:1317
folio_wait_writeback+0xb0/0x100 mm/page-writeback.c:3124
f2fs_folio_wait_writeback+0x16c/0x240 fs/f2fs/segment.c:4210
f2fs_update_inode+0x65/0x2620 fs/f2fs/inode.c:668
f2fs_update_inode_page+0x131/0x190 fs/f2fs/inode.c:783
f2fs_evict_inode+0xd4a/0x19c0 fs/f2fs/inode.c:936
evict+0x504/0x9c0 fs/inode.c:810
__dentry_kill+0x209/0x660 fs/dcache.c:669
dput+0x19f/0x2b0 fs/dcache.c:911
__fput+0x68e/0xa70 fs/file_table.c:476
task_work_run+0x1d1/0x260 kernel/task_work.c:227
get_signal+0x11c5/0x1310 kernel/signal.c:2807
arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa12df8e9a9
RSP: 002b:00007fa12ee9c038 EFLAGS: 00000246 ORIG_RAX: 000000000000004b
RAX: fffffffffffffffb RBX: 00007fa12e1b5fa0 RCX: 00007fa12df8e9a9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000006
RBP: 00007fa12e010d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fa12e1b5fa0 R15: 00007ffc4eecd1e8
</TASK>
INFO: task syz.3.19:6741 blocked for more than 145 seconds.
Not tainted 6.17.0-rc1-syzkaller-g5344e5bb8255 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.19 state:D stack:24600 pid:6741 tgid:6740 ppid:6451
task_flags:0x400140 flags:0x00004006
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1742/0x4c70 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7058
io_schedule+0x81/0xe0 kernel/sched/core.c:7903
folio_wait_bit_common+0x6b0/0xb90 mm/filemap.c:1317
folio_wait_writeback+0xb0/0x100 mm/page-writeback.c:3124
f2fs_folio_wait_writeback+0x16c/0x240 fs/f2fs/segment.c:4210
f2fs_update_inode+0x65/0x2620 fs/f2fs/inode.c:668
f2fs_update_inode_page+0x131/0x190 fs/f2fs/inode.c:783
f2fs_evict_inode+0xd4a/0x19c0 fs/f2fs/inode.c:936
evict+0x504/0x9c0 fs/inode.c:810
__dentry_kill+0x209/0x660 fs/dcache.c:669
dput+0x19f/0x2b0 fs/dcache.c:911
__fput+0x68e/0xa70 fs/file_table.c:476
task_work_run+0x1d1/0x260 kernel/task_work.c:227
get_signal+0x11c5/0x1310 kernel/signal.c:2807
arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe96f58e9a9
RSP: 002b:00007fe9704b5038 EFLAGS: 00000246 ORIG_RAX: 000000000000004b
RAX: fffffffffffffffb RBX: 00007fe96f7b5fa0 RCX: 00007fe96f58e9a9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000006
RBP: 00007fe96f610d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fe96f7b5fa0 R15: 00007ffca3c68668
</TASK>
INFO: task syz.4.20:6754 blocked for more than 147 seconds.
Not tainted 6.17.0-rc1-syzkaller-g5344e5bb8255 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.20 state:D stack:24632 pid:6754 tgid:6753 ppid:6452
task_flags:0x400140 flags:0x00004006
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1742/0x4c70 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7058
io_schedule+0x81/0xe0 kernel/sched/core.c:7903
folio_wait_bit_common+0x6b0/0xb90 mm/filemap.c:1317
folio_wait_writeback+0xb0/0x100 mm/page-writeback.c:3124
f2fs_folio_wait_writeback+0x16c/0x240 fs/f2fs/segment.c:4210
f2fs_update_inode+0x65/0x2620 fs/f2fs/inode.c:668
f2fs_update_inode_page+0x131/0x190 fs/f2fs/inode.c:783
f2fs_evict_inode+0xd4a/0x19c0 fs/f2fs/inode.c:936
evict+0x504/0x9c0 fs/inode.c:810
__dentry_kill+0x209/0x660 fs/dcache.c:669
dput+0x19f/0x2b0 fs/dcache.c:911
__fput+0x68e/0xa70 fs/file_table.c:476
task_work_run+0x1d1/0x260 kernel/task_work.c:227
get_signal+0x11c5/0x1310 kernel/signal.c:2807
arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff9cc98e9a9
RSP: 002b:00007ff9cd7f2038 EFLAGS: 00000246 ORIG_RAX: 000000000000004b
RAX: fffffffffffffffb RBX: 00007ff9ccbb5fa0 RCX: 00007ff9cc98e9a9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000006
RBP: 00007ff9cca10d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007ff9ccbb5fa0 R15: 00007ffee71ef8b8
</TASK>
INFO: task syz.0.21:6781 blocked for more than 148 seconds.
Not tainted 6.17.0-rc1-syzkaller-g5344e5bb8255 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.21 state:D stack:24136 pid:6781 tgid:6780 ppid:6438
task_flags:0x400140 flags:0x00004006
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1742/0x4c70 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7058
io_schedule+0x81/0xe0 kernel/sched/core.c:7903
folio_wait_bit_common+0x6b0/0xb90 mm/filemap.c:1317
folio_wait_writeback+0xb0/0x100 mm/page-writeback.c:3124
f2fs_folio_wait_writeback+0x16c/0x240 fs/f2fs/segment.c:4210
f2fs_update_inode+0x65/0x2620 fs/f2fs/inode.c:668
f2fs_update_inode_page+0x131/0x190 fs/f2fs/inode.c:783
f2fs_evict_inode+0xd4a/0x19c0 fs/f2fs/inode.c:936
evict+0x504/0x9c0 fs/inode.c:810
__dentry_kill+0x209/0x660 fs/dcache.c:669
dput+0x19f/0x2b0 fs/dcache.c:911
__fput+0x68e/0xa70 fs/file_table.c:476
task_work_run+0x1d1/0x260 kernel/task_work.c:227
get_signal+0x11c5/0x1310 kernel/signal.c:2807
arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9d4a38e9a9
RSP: 002b:00007f9d4b2c5038 EFLAGS: 00000246 ORIG_RAX: 000000000000004b
RAX: fffffffffffffffb RBX: 00007f9d4a5b5fa0 RCX: 00007f9d4a38e9a9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000006
RBP: 00007f9d4a410d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f9d4a5b5fa0 R15: 00007ffcd0c959d8
</TASK>
Showing all locks held in the system:
5 locks held by kworker/u8:1/13:
2 locks held by ksoftirqd/1/23:
#0: ffff8880b8739e18 (&rq->__lock){-.-.}-{2:2}, at:
raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:636
#1: ffff8880b8724008 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880
kernel/sched/psi.c:933
1 lock held by khungtaskd/31:
#0: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire
include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock
include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at:
debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
4 locks held by kworker/u8:2/36:
2 locks held by getty/5617:
#0: ffff8880304d30a0 (&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.2.18/6729:
#0: ffff8880628e4618 (sb_internal#2){.+.+}-{0:0}, at:
f2fs_evict_inode+0x898/0x19c0 fs/f2fs/inode.c:892
1 lock held by syz.1.17/6734:
#0: ffff888026c9a618 (sb_internal#2){.+.+}-{0:0}, at:
f2fs_evict_inode+0x898/0x19c0 fs/f2fs/inode.c:892
1 lock held by syz.3.19/6741:
#0: ffff888029132618 (sb_internal#2){.+.+}-{0:0}, at:
f2fs_evict_inode+0x898/0x19c0 fs/f2fs/inode.c:892
1 lock held by syz.4.20/6754:
#0: ffff88802c33e618 (sb_internal#2){.+.+}-{0:0}, at:
f2fs_evict_inode+0x898/0x19c0 fs/f2fs/inode.c:892
1 lock held by syz.0.21/6781:
#0: ffff888059ebe618 (sb_internal#2){.+.+}-{0:0}, at:
f2fs_evict_inode+0x898/0x19c0 fs/f2fs/inode.c:892
4 locks held by syz.6.23/7017:
#0: ffff888062b55478 (&sbi->gc_lock){+.+.}-{4:4}, at: f2fs_down_write
fs/f2fs/f2fs.h:2296 [inline]
#0: ffff888062b55478 (&sbi->gc_lock){+.+.}-{4:4}, at:
f2fs_issue_checkpoint+0x3a8/0x610 fs/f2fs/checkpoint.c:1902
#1: ffff888062b54318 (&sbi->cp_global_sem){+.+.}-{4:4}, at: f2fs_down_write
fs/f2fs/f2fs.h:2296 [inline]
#1: ffff888062b54318 (&sbi->cp_global_sem){+.+.}-{4:4}, at:
f2fs_write_checkpoint+0x27f/0x2440 fs/f2fs/checkpoint.c:1672
#2: ffff888062b543b0 (&sbi->cp_rwsem){++++}-{4:4}, at: f2fs_down_write
fs/f2fs/f2fs.h:2296 [inline]
#2: ffff888062b543b0 (&sbi->cp_rwsem){++++}-{4:4}, at: f2fs_lock_all
fs/f2fs/f2fs.h:2376 [inline]
#2: ffff888062b543b0 (&sbi->cp_rwsem){++++}-{4:4}, at: block_operations
fs/f2fs/checkpoint.c:1221 [inline]
#2: ffff888062b543b0 (&sbi->cp_rwsem){++++}-{4:4}, at:
f2fs_write_checkpoint+0x55f/0x2440 fs/f2fs/checkpoint.c:1687
#3: ffff888062b54448 (&sbi->node_write){++++}-{4:4}, at: f2fs_down_write
fs/f2fs/f2fs.h:2296 [inline]
#3: ffff888062b54448 (&sbi->node_write){++++}-{4:4}, at: block_operations
fs/f2fs/checkpoint.c:1271 [inline]
#3: ffff888062b54448 (&sbi->node_write){++++}-{4:4}, at:
f2fs_write_checkpoint+0xe29/0x2440 fs/f2fs/checkpoint.c:1687
1 lock held by syz.5.22/7014:
#0: ffff88802ffba618 (sb_internal#2){.+.+}-{0:0}, at:
f2fs_evict_inode+0x898/0x19c0 fs/f2fs/inode.c:892
1 lock held by syz.7.24/7016:
#0: ffff88807dda4618 (sb_internal#2){.+.+}-{0:0}, at:
f2fs_evict_inode+0x898/0x19c0 fs/f2fs/inode.c:892
1 lock held by syz.8.25/7019:
#0: ffff88805beaa618 (sb_internal#2){.+.+}-{0:0}, at:
f2fs_evict_inode+0x898/0x19c0 fs/f2fs/inode.c:892
1 lock held by syz.9.26/7021:
#0: ffff8880339fe618 (sb_internal#2){.+.+}-{0:0}, at:
f2fs_evict_inode+0x898/0x19c0 fs/f2fs/inode.c:892
1 lock held by syz.2.497/8114:
#0: ffff8880b8739e18 (&rq->__lock){-.-.}-{2:2}, at:
raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:636
2 locks held by syz.4.499/8118:
2 locks held by syz.1.500/8120:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted
6.17.0-rc1-syzkaller-g5344e5bb8255 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google
07/12/2025
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+0xf93/0xfe0 kernel/hung_task.c:491
kthread+0x711/0x8a0 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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 16 Comm: rcu_preempt Not tainted
6.17.0-rc1-syzkaller-g5344e5bb8255 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google
07/12/2025
RIP: 0010:lookup_object lib/debugobjects.c:423 [inline]
RIP: 0010:lookup_object_or_alloc lib/debugobjects.c:662 [inline]
RIP: 0010:debug_object_assert_init+0xf8/0x380 lib/debugobjects.c:1008
Code: fd 4c 89 34 24 4c 8b 6d 00 45 31 f6 eb 07 4d 8b 6d 00 41 ff c6 4d 85 ed
74 3c 4d 8d 65 18 4c 89 e0 48 c1 e8 03 42 80 3c 38 00 <74> 08 4c 89 e7 e8 0e b4
58 fd 49 39 1c 24 0f 84 ef 00 00 00 4c 89
RSP: 0018:ffffc900001578b8 EFLAGS: 00000046
RAX: 1ffff110082b7c26 RBX: ffffc90000157a80 RCX: dffffc0000000000
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc900001577a0
RBP: ffffffff99d4d290 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff5200002aef4 R12: ffff8880415be130
R13: ffff8880415be118 R14: 0000000000000000 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff888125d54000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f449da77000 CR3: 0000000076c48000 CR4: 00000000003526f0
Call Trace:
<TASK>
debug_timer_assert_init kernel/time/timer.c:803 [inline]
debug_assert_init kernel/time/timer.c:848 [inline]
__try_to_del_timer_sync+0x29/0x3a0 kernel/time/timer.c:1457
__timer_delete_sync+0x1fe/0x2d0 kernel/time/timer.c:1620
schedule_timeout+0x133/0x270 kernel/time/sleep_timeout.c:100
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
kthread+0x711/0x8a0 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>
Tested on:
commit: 5344e5bb f2fs: cover f2fs_update_inode_page() w/ node_..
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/chao/linux.git
bugfix/common
console output: https://syzkaller.appspot.com/x/log.txt?x=1683f9a2580000
kernel config: https://syzkaller.appspot.com/x/.config?x=1f6e4cb78ac1b7bb
dashboard link: https://syzkaller.appspot.com/bug?extid=803dd716c4310d16ff3a
compiler: Debian clang version 20.1.7
(++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
Note: no patches were applied.
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