[f2fs-dev] [syzbot] [f2fs?] INFO: task hung in f2fs_fallocate (6)

syzbot
2026-02-26T06:18:35Z

Hello,

syzbot found the following issue on:

HEAD commit: d4906ae14a5f Add linux-next specific files for 20260220
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=13f24006580000
kernel config: https://syzkaller.appspot.com/x/.config?x=cdf9388b212a2b28
dashboard link: https://syzkaller.appspot.com/bug?extid=73d18077a2323a1fdb5e
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1312395a580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13a4855a580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/1537e9684d19/disk-d4906ae1.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/dd6c9977a9cf/vmlinux-d4906ae1.xz
kernel image: https://storage.googleapis.com/syzbot-assets/f1d85a2d6c78/bzImage-d4906ae1.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/2471b6f6a299/mount_0.gz
fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=149a0202580000)

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+73d18077a2323a1fdb5e@syzkaller.appspotmail.com

INFO: task syz.1.18:6046 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.18 state:D stack:28832 pid:6046 tgid:6042 ppid:6019 task_flags:0x400040 flags:0x00080002
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x1585/0x5340 kernel/sched/core.c:6907
__schedule_loop kernel/sched/core.c:6989 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7004
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7061
rwsem_down_write_slowpath+0x899/0x1040 kernel/locking/rwsem.c:1185
__down_write_common kernel/locking/rwsem.c:1317 [inline]
__down_write kernel/locking/rwsem.c:1326 [inline]
down_write+0x1bc/0x200 kernel/locking/rwsem.c:1591
inode_lock include/linux/fs.h:1028 [inline]
f2fs_fallocate+0x24e/0x9b0 fs/f2fs/file.c:2013
vfs_fallocate+0x669/0x7e0 fs/open.c:340
ksys_fallocate fs/open.c:364 [inline]
__do_sys_fallocate fs/open.c:369 [inline]
__se_sys_fallocate fs/open.c:367 [inline]
__x64_sys_fallocate+0xc0/0x110 fs/open.c:367
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa61c59c629
RSP: 002b:00007fa61d448028 EFLAGS: 00000246
ORIG_RAX: 000000000000011d
RAX: ffffffffffffffda RBX: 00007fa61c816090 RCX: 00007fa61c59c629
RDX: 0000000000004000 RSI: 0000000000000008 RDI: 0000000000000004
RBP: 00007fa61c632b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000010000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa61c816128 R14: 00007fa61c816090 R15: 00007ffcfdb9b178
</TASK>

Showing all locks held in the system:

---
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