INFO: task hung in diNewExt

Status: upstream: reported C repro on 2025/10/24 23:11
Subsystems: jfs
Labels: prio:normal
[Documentation on labels]
Reported-by: syzbot+b367cace420c21becba6@syzkaller.appspotmail.com
First crash: 293d, last: 293d
Cause bisection: failed (error log, bisect log)
  
▶ ▼ ✨ AI Jobs (2)
ID Workflow Result Correct Bug Created Started Finished Revision
093a42b1 assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ✅ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ INFO: task hung in diNewExt 2026/05/30 07:43 2026/05/30 07:43 2026/05/30 08:47 6b4a8443
6b6c7cc3 assessment-security 💥 INFO: task hung in diNewExt 2026/05/14 08:39 2026/05/14 08:39 2026/05/14 08:40 6ccb967e
▶ ▼ Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [jfs?] INFO: task hung in diNewExt 0 (1) 2025/10/24 23:11
▶ ▼ Last patch testing requests (4)
Created Duration User Patch Repo Result
2026/06/05 09:41 2h23m retest repro linux-next error
2026/03/27 08:45 19m retest repro linux-next report log
2026/01/16 08:03 30m retest repro linux-next report log
2025/11/07 05:01 1h25m retest repro linux-next report log

Sample crash report:
INFO: task syz.2.19:6098 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.19        state:D stack:24120 pid:6098  tgid:6097  ppid:5976   task_flags:0x400140 flags:0x00080003
Call Trace:
 context_switch kernel/sched/core.c:5254 [inline]
 __schedule+0x17c4/0x4d60 kernel/sched/core.c:6862
 __schedule_loop kernel/sched/core.c:6944 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6959
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7016
 rwsem_down_read_slowpath+0x5fd/0x8f0 kernel/locking/rwsem.c:1086
 __down_read_common kernel/locking/rwsem.c:1261 [inline]
 __down_read kernel/locking/rwsem.c:1274 [inline]
 down_read_nested+0x9a/0x2f0 kernel/locking/rwsem.c:1663
 diNewExt+0x9af/0x3150 fs/jfs/jfs_imap.c:2261
 diAllocExt fs/jfs/jfs_imap.c:1952 [inline]
 diAllocAG+0xe86/0x1df0 fs/jfs/jfs_imap.c:1669
 diAlloc+0x1d5/0x1680 fs/jfs/jfs_imap.c:1590
 ialloc+0x8c/0x8f0 fs/jfs/jfs_inode.c:56
 jfs_mkdir+0x193/0xa70 fs/jfs/namei.c:225
 vfs_mkdir+0x306/0x510 fs/namei.c:4453
 do_mkdirat+0x247/0x590 fs/namei.c:4486
 __do_sys_mkdirat fs/namei.c:4503 [inline]
 __se_sys_mkdirat fs/namei.c:4501 [inline]
 __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4501
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa19698efc9
RSP: 002b:00007fa197895038 EFLAGS: 00000246
RBP: 00007fa196a11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
INFO: task syz.0.17:6103 blocked for more than 148 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.17        state:D
 stack:25592 pid:6103  tgid:6102  ppid:5971   task_flags:0x400140 flags:0x00080003
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5254 [inline]
 __schedule+0x17c4/0x4d60 kernel/sched/core.c:6862
 __schedule_loop kernel/sched/core.c:6944 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6959
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7016
 rwsem_down_read_slowpath+0x5fd/0x8f0 kernel/locking/rwsem.c:1086
 __down_read_common kernel/locking/rwsem.c:1261 [inline]
 __down_read kernel/locking/rwsem.c:1274 [inline]
 down_read_nested+0x9a/0x2f0 kernel/locking/rwsem.c:1663
 dbAlloc+0x3a7/0xba0 fs/jfs/jfs_dmap.c:790
 diNewExt+0x9af/0x3150 fs/jfs/jfs_imap.c:2261
 diAllocExt fs/jfs/jfs_imap.c:1952 [inline]
 diAllocAG+0xe86/0x1df0 fs/jfs/jfs_imap.c:1669
 diAlloc+0x1d5/0x1680 fs/jfs/jfs_imap.c:1590
 ialloc+0x8c/0x8f0 fs/jfs/jfs_inode.c:56
 jfs_mkdir+0x193/0xa70 fs/jfs/namei.c:225

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/10/24 02:43 linux-next aaa9c3550b60 c0460fcd .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 diNewExt
* Struck through repros no longer work on HEAD.