INFO: task hung in f2fs_fallocate (6)

Status: auto-obsoleted due to no activity on 2026/10/13 14:04
Subsystems: f2fs
Labels: prio:high
[Documentation on labels]
Reported-by: syzbot+73d18077a2323a1fdb5e@syzkaller.appspotmail.com
First crash: 234d, last: 204d
Cause bisection: failed (error log, bisect log)
  
▶ ▼ ✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision
4d407269 assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ✅ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ INFO: task hung in f2fs_fallocate (6) 2026/05/26 14:45 2026/05/26 14:45 2026/05/26 15:24 76d4b4b1
▶ ▼ Discussions (2)
Title Replies (including bot) Last reply
[syzbot] Monthly f2fs report (Mar 2026) 0 (1) 2026/03/09 12:29
[syzbot] [f2fs?] INFO: task hung in f2fs_fallocate (6) 0 (1) 2026/02/26 06:18
▶ ▼ Similar bugs (6)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in f2fs_fallocate (4) f2fs 1 11 654d 822d 0/29 auto-obsoleted due to no activity on 2025/03/28 19:38
upstream INFO: task hung in f2fs_fallocate (3) f2fs 1 3 948d 964d 0/29 auto-obsoleted due to no activity on 2024/06/07 18:19
upstream INFO: task hung in f2fs_fallocate f2fs 1 1 1279d 1279d 0/29 auto-obsoleted due to no activity on 2023/07/12 13:35
upstream INFO: task hung in f2fs_fallocate (5) f2fs 1 syz, C done error 3 516d 537d 0/29 auto-obsoleted due to no activity on 2025/08/28 03:32
upstream INFO: task hung in f2fs_fallocate (2) f2fs 1 3 1061d 1064d 0/29 auto-obsoleted due to no activity on 2024/02/15 04:04
linux-5.15 INFO: task hung in f2fs_fallocate 1 2 723d 723d 0/3 auto-obsoleted due to no activity on 2025/01/28 07:01
▶ ▼ Last patch testing requests (10)
Created Duration User Patch Repo Result
2026/10/13 05:53 2h23m retest repro linux-next no crash job log log
2026/10/13 05:53 28m retest repro linux-next no crash job log log
2026/10/13 05:53 29m retest repro linux-next no crash job log log
2026/08/17 21:43 26m retest repro linux-next no crash job log log
2026/08/01 14:03 30m retest repro linux-next error
2026/08/01 14:03 30m retest repro linux-next error
2026/08/01 14:03 37m retest repro linux-next error
2026/06/01 09:13 2h59m retest repro linux-next error
2026/06/01 08:35 3h25m retest repro linux-next error
2026/05/18 13:40 30m retest repro linux-next log

Sample crash report:
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:

Crashes (7):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/02/23 03:15 linux-next d4906ae14a5f 6e7b5511 .config console 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_fallocate
2026/02/23 00:11 linux-next d4906ae14a5f 6e7b5511 .config console 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_fallocate
2026/02/22 20:37 linux-next d4906ae14a5f 6e7b5511 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci-upstream-linux-next-kasan-gce-root INFO: task hung in f2fs_fallocate
2026/02/22 13:12 linux-next d4906ae14a5f 6e7b5511 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci-upstream-linux-next-kasan-gce-root INFO: task hung in f2fs_fallocate
2026/02/22 09:49 linux-next d4906ae14a5f 6e7b5511 .config console 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_fallocate
2026/02/22 06:08 linux-next d4906ae14a5f 6e7b5511 .config console 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_fallocate
2026/02/22 01:48 linux-next d4906ae14a5f 6e7b5511 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in f2fs_fallocate
* Struck through repros no longer work on HEAD.