syzbot


INFO: task hung in gfs2_jhead_process_page

Status: upstream: reported C repro on 2025/08/11 14:51
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+60b5e90b6d2c52328fb9@syzkaller.appspotmail.com
First crash: 13d, last: 12d
Bug presence (1)
Date Name Commit Repro Result
2025/08/11 upstream (ToT) 8f5ae30d69d7 C [report] INFO: task hung in gfs2_jhead_process_page
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in gfs2_jhead_process_page cluster 1 C error 679 13h29m 977d 0/29 upstream: reported C repro on 2022/12/21 02:23
linux-6.1 INFO: task hung in gfs2_jhead_process_page origin:upstream 1 C error 55 29d 890d 0/3 upstream: reported C repro on 2023/03/18 15:36
linux-5.15 INFO: task hung in gfs2_jhead_process_page origin:upstream 1 C error 67 11h10m 898d 0/3 upstream: reported C repro on 2023/03/10 07:53

Sample crash report:
INFO: task kworker/0:3:1194 blocked for more than 143 seconds.
      Not tainted 6.6.101-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:3     state:D stack:25704 pid:1194  ppid:2      flags:0x00004000
Workqueue: gfs2_recovery gfs2_recover_func
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x14d2/0x44d0 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 io_schedule+0x80/0xd0 kernel/sched/core.c:9023
 folio_wait_bit_common+0x6eb/0xf70 mm/filemap.c:1329
 folio_wait_locked include/linux/pagemap.h:1149 [inline]
 gfs2_jhead_process_page+0x17a/0x700 fs/gfs2/lops.c:477
 gfs2_find_jhead+0xbe5/0xd20 fs/gfs2/lops.c:594
 gfs2_recover_func+0x688/0x1c60 fs/gfs2/recovery.c:460
 process_one_work kernel/workqueue.c:2634 [inline]
 process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
INFO: task syz.0.17:5946 blocked for more than 143 seconds.
      Not tainted 6.6.101-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.17        state:D stack:24616 pid:5946  ppid:5901   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x14d2/0x44d0 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 bit_wait+0x11/0xd0 kernel/sched/wait_bit.c:199
 __wait_on_bit+0xac/0x2d0 kernel/sched/wait_bit.c:49
 out_of_line_wait_on_bit+0x123/0x170 kernel/sched/wait_bit.c:64
 wait_on_bit include/linux/wait_bit.h:76 [inline]
 gfs2_recover_journal+0xda/0x130 fs/gfs2/recovery.c:577
 init_journal+0x17c5/0x2260 fs/gfs2/ops_fstype.c:833
 init_inodes+0xdb/0x320 fs/gfs2/ops_fstype.c:886
 gfs2_fill_super+0x1815/0x1f80 fs/gfs2/ops_fstype.c:1266
 get_tree_bdev+0x3e4/0x510 fs/super.c:1591
 gfs2_get_tree+0x51/0x1e0 fs/gfs2/ops_fstype.c:1344
 vfs_get_tree+0x8c/0x280 fs/super.c:1764
 do_new_mount+0x24b/0xa40 fs/namespace.c:3371
 do_mount fs/namespace.c:3711 [inline]
 __do_sys_mount fs/namespace.c:3920 [inline]
 __se_sys_mount+0x2da/0x3c0 fs/namespace.c:3897
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f468559038a
RSP: 002b:00007ffda6c60148 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffda6c601d0 RCX: 00007f468559038a
RDX: 0000200000000140 RSI: 0000200000037f80 RDI: 00007ffda6c60190
RBP: 0000200000000140 R08: 00007ffda6c601d0 R09: 0000000002810000
R10: 0000000002810000 R11: 0000000000000246 R12: 0000200000037f80
R13: 00007ffda6c60190 R14: 0000000000038014 R15: 00002000000001c0
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/29:
 #0: ffffffff8cd2fba0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #0: ffffffff8cd2fba0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
 #0: ffffffff8cd2fba0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
2 locks held by kworker/0:3/1194:
 #0: ffff88801eec9138 ((wq_completion)gfs2_recovery){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #0: ffff88801eec9138 ((wq_completion)gfs2_recovery){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
 #1: ffffc900049cfd00 ((work_completion)(&jd->jd_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #1: ffffc900049cfd00 ((work_completion)(&jd->jd_work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
2 locks held by getty/5549:
 #0: ffff88802deca0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217
1 lock held by syz.0.17/5946:
 #0: ffff88802cb960e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: __super_lock fs/super.c:56 [inline]
 #0: ffff88802cb960e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
 #0: ffff88802cb960e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: get_tree_bdev+0x344/0x510 fs/super.c:1589

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

NMI backtrace for cpu 1
CPU: 1 PID: 29 Comm: khungtaskd Not tainted 6.6.101-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x39b/0x3d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
 watchdog+0xf41/0xf80 kernel/hung_task.c:379
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 5151 Comm: klogd Not tainted 6.6.101-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:update_min_vruntime kernel/sched/fair.c:792 [inline]
RIP: 0010:update_curr+0x3a8/0x7f0 kernel/sched/fair.c:1215
Code: 08 48 89 df e8 69 dd 7d 00 4c 8b 2b 4d 85 f6 74 5d 49 83 c6 68 4c 89 f0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 <74> 08 4c 89 f7 e8 3e dd 7d 00 49 8b 06 4c 39 e8 4c 0f 48 e8 eb 2e
RSP: 0018:ffffc900032876c0 EFLAGS: 00000046
RAX: 1ffff1100364e01d RBX: ffff88807e13dae8 RCX: dffffc0000000000
RDX: 0000000000000009 RSI: ffffffff8aaacbc0 RDI: ffff88807e13dae8
RBP: 1ffff110171c78a7 R08: ffffffff8e4a84ef R09: 1ffffffff1c9509d
R10: dffffc0000000000 R11: fffffbfff1c9509e R12: 00000017c5f638a5
R13: 00000017c5f9f7d0 R14: ffff88801b2700e8 R15: ffff8880b8e3c538
FS:  00007f000db17c80(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f43627ff000 CR3: 000000002e01a000 CR4: 00000000003506f0
Call Trace:
 <TASK>
 enqueue_entity+0x62/0x1580 kernel/sched/fair.c:5297
 enqueue_task_fair+0x59b/0xb00 kernel/sched/fair.c:6763
 enqueue_task+0x182/0x2c0 kernel/sched/core.c:2101
 activate_task kernel/sched/core.c:2131 [inline]
 ttwu_do_activate+0x1d6/0x7d0 kernel/sched/core.c:3790
 ttwu_queue kernel/sched/core.c:4032 [inline]
 try_to_wake_up+0x654/0x10b0 kernel/sched/core.c:4349
 autoremove_wake_function+0x17/0x100 kernel/sched/wait.c:424
 __wake_up_common+0x2a4/0x4e0 kernel/sched/wait.c:107
 __wake_up_common_lock kernel/sched/wait.c:138 [inline]
 __wake_up_sync_key+0x111/0x190 kernel/sched/wait.c:213
 sock_def_readable+0x1e1/0x430 net/core/sock.c:3329
 unix_dgram_sendmsg+0x10cc/0x1720 net/unix/af_unix.c:2141
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 __sys_sendto+0x46a/0x620 net/socket.c:2201
 __do_sys_sendto net/socket.c:2213 [inline]
 __se_sys_sendto net/socket.c:2209 [inline]
 __x64_sys_sendto+0xde/0xf0 net/socket.c:2209
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f000dc67407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffc5077e200 EFLAGS: 00000202 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f000db17c80 RCX: 00007f000dc67407
RDX: 000000000000008b RSI: 00007ffc5077e340 RDI: 0000000000000003
RBP: 00007ffc5077e770 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000004000 R11: 0000000000000202 R12: 00007ffc5077e788
R13: 00007ffc5077e340 R14: 0000000000000070 R15: 00007ffc5077e340
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/11 18:21 linux-6.6.y 3a8ababb8b6a 32a0e5ed .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-6-kasan INFO: task hung in gfs2_jhead_process_page
2025/08/11 14:50 linux-6.6.y 3a8ababb8b6a 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: task hung in gfs2_jhead_process_page
* Struck through repros no longer work on HEAD.