syzbot


INFO: task hung in lmLogOpen (3)

Status: auto-obsoleted due to no activity on 2026/06/02 19:54
Subsystems: jfs
Labels: prio:high
[Documentation on labels]
First crash: 122d, last: 120d
✨ AI Jobs (2)
ID Workflow Result Correct Bug Created Started Finished Revision Error
a2236c4f-cb30-451a-8c40-a61c19a20e38 assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ✅ NetworkTrigger: ❌ PeripheralTrigger: ✅ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ INFO: task hung in lmLogOpen (3) 2026/05/31 08:27 2026/05/31 08:27 2026/05/31 09:05 6b4a844333e83556da95d61d7f207e7ef5cd4bc6

			
		
3e684971-126d-46ad-8528-006b426fe93e assessment-security 💥 INFO: task hung in lmLogOpen (3) 2026/05/14 15:00 2026/05/14 15:00 2026/05/14 15:01 6ccb967e465e832a7bfd7a116ad00d52a0923a5d
failed to run ["git" "pull" "origin" "HEAD" "--depth=1" "--allow-unrelated-histories"]: exit status 128
From /app/workdir/repo/linux
 * branch                HEAD       -> FETCH_HEAD
Updating files:  ...
truncated to first 200 bytes; open job for full error
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.6 INFO: task hung in lmLogOpen 1 2 243d 301d 0/2 auto-obsoleted due to no activity on 2026/02/09 19:50
upstream INFO: task hung in lmLogOpen jfs 1 2 751d 762d 0/29 auto-obsoleted due to no activity on 2024/09/10 01:34
upstream INFO: task hung in lmLogOpen (2) jfs 1 14 237d 605d 0/29 auto-obsoleted due to no activity on 2026/02/06 01:14

Sample crash report:
INFO: task syz.3.177:7534 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.177       state:D stack:25344 pid:7534  tgid:7533  ppid:7047   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5295 [inline]
 __schedule+0x1553/0x5240 kernel/sched/core.c:6908
 __schedule_loop kernel/sched/core.c:6990 [inline]
 rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7286
 rt_mutex_slowlock_block+0x508/0x680 kernel/locking/rtmutex.c:1647
 __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]
 __rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1760 [inline]
 rt_mutex_slowlock+0x2dc/0x7b0 kernel/locking/rtmutex.c:1800
 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline]
 __mutex_lock_common kernel/locking/rtmutex_api.c:534 [inline]
 mutex_lock_nested+0x168/0x1d0 kernel/locking/rtmutex_api.c:552
 open_dummy_log fs/jfs/jfs_logmgr.c:1191 [inline]
 lmLogOpen+0x1a1/0xfa0 fs/jfs/jfs_logmgr.c:1066
 jfs_mount_rw+0xee/0x670 fs/jfs/jfs_mount.c:257
 jfs_fill_super+0x754/0xd80 fs/jfs/super.c:532
 get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1694
 vfs_get_tree+0x92/0x2a0 fs/super.c:1754
 fc_mount fs/namespace.c:1193 [inline]
 do_new_mount_fc fs/namespace.c:3763 [inline]
 do_new_mount+0x341/0xd30 fs/namespace.c:3839
 do_mount fs/namespace.c:4172 [inline]
 __do_sys_mount fs/namespace.c:4361 [inline]
 __se_sys_mount+0x31d/0x420 fs/namespace.c:4338
 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: 0033:0x7ff3c76ada0a
RSP: 002b:00007ff3c58fde58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ff3c58fdee0 RCX: 00007ff3c76ada0a
RDX: 0000200000007ec0 RSI: 0000200000000180 RDI: 00007ff3c58fdea0
RBP: 0000200000007ec0 R08: 00007ff3c58fdee0 R09: 0000000003800400
R10: 0000000003800400 R11: 0000000000000246 R12: 0000200000000180
R13: 00007ff3c58fdea0 R14: 0000000000006215 R15: 0000200000007f40
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/38:
 #0: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
 #0: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
 #0: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
4 locks held by kworker/u8:6/160:
 #0: ffff88801aed9138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline]
 #0: ffff88801aed9138 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358
 #1: ffffc900039efc40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
 #1: ffffc900039efc40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358
 #2: ffffffff8f14be80 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:675
 #3: ffff88803da897b8 (&wg->device_update_lock){+.+.}-{4:4}, at: wg_destruct+0x116/0x310 drivers/net/wireguard/device.c:249
3 locks held by kworker/u8:13/5010:
 #0: ffff888031e4c138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline]
 #0: ffff888031e4c138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358
 #1: ffffc90010d5fc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
 #1: ffffc90010d5fc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358
 #2: ffffffff8f15a6b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 #2: ffffffff8f15a6b8 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x124/0x1680 net/ipv6/addrconf.c:4198
2 locks held by dhcpcd/5458:
 #0: ffff88805267e928 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: netlink_dump+0xe4/0xe80 net/netlink/af_netlink.c:2267
 #1: ffffffff8f15a6b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #1: ffffffff8f15a6b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dumpit+0x92/0x200 net/core/rtnetlink.c:6826
2 locks held by getty/5554:
 #0: ffff8880373580a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90003e762e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211
3 locks held by kworker/1:3/5783:
 #0: ffff888019c03d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline]
 #0: ffff888019c03d38 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358
 #1: ffffc9000483fc40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
 #1: ffffc9000483fc40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358
 #2: ffff88803d82b260 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x222/0x3e0 drivers/net/netdevsim/fib.c:1490
2 locks held by syz-executor/6261:
 #0: ffff88803bcbe0d0 (&type->s_umount_key#77){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
 #0: ffff88803bcbe0d0 (&type->s_umount_key#77){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
 #0: ffff88803bcbe0d0 (&type->s_umount_key#77){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508
 #1: ffffffff8e24ef58 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443
2 locks held by syz.3.177/7534:
 #0: ffff8880591d80d0 (&type->s_umount_key#75/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xac0 fs/super.c:345
 #1: ffffffff8e24ef58 (jfs_log_mutex){+.+.}-{4:4}, at: open_dummy_log fs/jfs/jfs_logmgr.c:1191 [inline]
 #1: ffffffff8e24ef58 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogOpen+0x1a1/0xfa0 fs/jfs/jfs_logmgr.c:1066
2 locks held by syz.7.210/7798:
 #0: ffff888032ad40d0 (&type->s_umount_key#75/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xac0 fs/super.c:345
 #1: ffffffff8e24ef58 (jfs_log_mutex){+.+.}-{4:4}, at: open_dummy_log fs/jfs/jfs_logmgr.c:1191 [inline]
 #1: ffffffff8e24ef58 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogOpen+0x1a1/0xfa0 fs/jfs/jfs_logmgr.c:1066
1 lock held by syz-executor/8237:
 #0: ffffffff8f15a6b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 #0: ffffffff8f15a6b8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x404/0x1ad0 net/ipv4/devinet.c:978
1 lock held by syz-executor/8356:
 #0: ffffffff8f15a6b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 #0: ffffffff8f15a6b8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x404/0x1ad0 net/ipv4/devinet.c:978
1 lock held by syz-executor/8358:
2 locks held by syz-executor/8692:
 #0: ffffffff8f6a5750 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
 #0: ffffffff8f6a5750 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
 #0: ffffffff8f6a5750 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570
 #1: ffffffff8f15a6b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #1: ffffffff8f15a6b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
 #1: ffffffff8f15a6b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4071

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x135/0x170 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
 watchdog+0xfd9/0x1030 kernel/hung_task.c:515
 kthread+0x388/0x470 kernel/kthread.c:467
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 8735 Comm: syz-executor Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:__lt_find include/linux/rbtree_latch.h:-1 [inline]
RIP: 0010:latch_tree_find include/linux/rbtree_latch.h:210 [inline]
RIP: 0010:bpf_ksym_find kernel/bpf/core.c:716 [inline]
RIP: 0010:is_bpf_text_address+0xf0/0x2b0 kernel/bpf/core.c:749
Code: bd 00 00 00 00 00 fc ff df 44 8b 25 8a 55 cd 0b 44 89 e3 83 e3 01 4c 8d 3c dd f0 55 a1 8d 4c 89 f8 48 c1 e8 03 42 80 3c 28 00 <74> 08 4c 89 ff e8 36 63 56 00 4d 8b 3f 4d 85 ff 0f 84 c1 00 00 00
RSP: 0018:ffffc90005027270 EFLAGS: 00000246
RAX: 1ffffffff1b42abe RBX: 0000000000000000 RCX: ffff888027ef0000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc90005027358 R11: ffffffff81af6250 R12: 0000000000000004
R13: dffffc0000000000 R14: 00007fb8770cc42b R15: ffffffff8da155f0
FS:  0000555556b90500(0000) GS:ffff888126340000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb877345f40 CR3: 0000000063bd2000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 kernel_text_address+0xa5/0xe0 kernel/extable.c:125
 __kernel_text_address+0xd/0x30 kernel/extable.c:79
 unwind_get_return_address+0x4d/0x90 arch/x86/kernel/unwind_orc.c:385
 arch_stack_walk+0xfb/0x150 arch/x86/kernel/stacktrace.c:26
 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
 save_stack+0x124/0x230 mm/page_owner.c:165
 __set_page_owner+0x8d/0x4b0 mm/page_owner.c:341
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x231/0x280 mm/page_alloc.c:1889
 prep_new_page mm/page_alloc.c:1897 [inline]
 get_page_from_freelist+0x28bb/0x2950 mm/page_alloc.c:3962
 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5250
 __alloc_pages_noprof mm/page_alloc.c:5284 [inline]
 alloc_pages_bulk_noprof+0x5f1/0x7d0 mm/page_alloc.c:5204
 ___alloc_pages_bulk mm/kasan/shadow.c:345 [inline]
 __kasan_populate_vmalloc_do mm/kasan/shadow.c:370 [inline]
 __kasan_populate_vmalloc+0xc1/0x1d0 mm/kasan/shadow.c:424
 kasan_populate_vmalloc include/linux/kasan.h:580 [inline]
 alloc_vmap_area+0xd73/0x14b0 mm/vmalloc.c:2129
 __get_vm_area_node+0x226/0x350 mm/vmalloc.c:3232
 __vmalloc_node_range_noprof+0x372/0x1730 mm/vmalloc.c:4024
 vmalloc_user_noprof+0xad/0xe0 mm/vmalloc.c:4218
 kcov_ioctl+0x58/0x640 kernel/kcov.c:726
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xff/0x170 fs/ioctl.c:583
 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: 0033:0x7fb8770cc42b
Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00
RSP: 002b:00007ffd914e4320 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000100000 RCX: 00007fb8770cc42b
RDX: 0000000000100000 RSI: ffffffff80086301 RDI: 00000000000000d7
RBP: 00007fb877345f40 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 0000000000000003 R14: 00007ffd914e45d8 R15: 0000000000000000
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/03/04 19:50 upstream ecc64d2dc9ff e6b6b96b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in lmLogOpen
2026/03/03 03:18 upstream af4e9ef3d784 28b83e23 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in lmLogOpen
* Struck through repros no longer work on HEAD.