[v6.6] INFO: task hung in release_metapage
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syzbot
Dec 21, 2025, 3:11:34 PM (3 days ago) Dec 21
to syzkaller...@googlegroups.com
Hello,
syzbot found the following issue on:
HEAD commit: 5fa4793a2d2d Linux 6.6.119
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=16b2f77c580000
kernel config: https://syzkaller.appspot.com/x/.config?x=691a6769a86ac817
dashboard link: https://syzkaller.appspot.com/bug?extid=fb8f78a315b6402af738
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/63699875f1dd/disk-5fa4793a.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/8506652fcb6f/vmlinux-5fa4793a.xz
kernel image: https://storage.googleapis.com/syzbot-assets/1b30ceed1710/bzImage-5fa4793a.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+fb8f78...@syzkaller.appspotmail.com
INFO: task syz.5.2147:15432 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.2147 state:D stack:26224 pid:15432 ppid:6610 flags:0x00004004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
io_schedule+0x80/0xd0 kernel/sched/core.c:9022
folio_wait_bit_common+0x6eb/0xf70 mm/filemap.c:1329
release_metapage+0x97/0x870 fs/jfs/jfs_metapage.c:764
discard_metapage fs/jfs/jfs_metapage.h:88 [inline]
__get_metapage+0xa69/0xfa0 fs/jfs/jfs_metapage.c:644
dtSearch+0x591/0x21b0 fs/jfs/jfs_dtree.c:624
jfs_lookup+0x156/0x380 fs/jfs/namei.c:1459
lookup_open fs/namei.c:3474 [inline]
open_last_lookups fs/namei.c:3564 [inline]
path_openat+0x10b8/0x3190 fs/namei.c:3794
do_filp_open+0x1c5/0x3d0 fs/namei.c:3824
do_sys_openat2+0x12c/0x1c0 fs/open.c:1421
do_sys_open fs/open.c:1436 [inline]
__do_sys_openat fs/open.c:1452 [inline]
__se_sys_openat fs/open.c:1447 [inline]
__x64_sys_openat+0x139/0x160 fs/open.c:1447
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: 0033:0x7f008278f749
RSP: 002b:00007f00836ea038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f00829e6090 RCX: 00007f008278f749
RDX: 0000000000040042 RSI: 0000200000000240 RDI: ffffffffffffff9c
RBP: 00007f0082813f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f00829e6128 R14: 00007f00829e6090 R15: 00007fff2980cf58
</TASK>
Showing all locks held in the system:
2 locks held by kworker/u4:0/11:
#0: ffff888017871538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888017871538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffff8880b8e289c0 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:189 [inline]
#1: ffff8880b8e289c0 (psi_seq){-.-.}-{0:0}, at: __schedule+0x20ee/0x44d0 kernel/sched/core.c:6694
2 locks held by kworker/1:0/23:
#0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc900001d7d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc900001d7d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
1 lock held by khungtaskd/29:
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
3 locks held by kworker/u4:11/3479:
#0: ffff888141e4e938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888141e4e938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc9000cdc7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc9000cdc7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff88805f0e60e0 (&type->s_umount_key#69){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
2 locks held by getty/5533:
#0: ffff88814e3800a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217
2 locks held by udevd/10085:
#0: ffff8880b8e3c018 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:566
#1: ffff8880b8e289c0 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:189 [inline]
#1: ffff8880b8e289c0 (psi_seq){-.-.}-{0:0}, at: __schedule+0x20ee/0x44d0 kernel/sched/core.c:6694
3 locks held by kworker/1:7/12924:
#0: ffff8881400fa938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff8881400fa938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc9000b76fd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc9000b76fd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff888024a64190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:995 [inline]
#2: ffff888024a64190 (&dev->mutex){....}-{3:3}, at: hub_event+0x185/0x49c0 drivers/usb/core/hub.c:5861
1 lock held by syz-executor/14044:
#0: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline]
#0: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x448/0x830 kernel/rcu/tree_exp.h:1004
1 lock held by syz-executor/14162:
1 lock held by syz.5.2147/15432:
#0: ffff8880615e58d0 (&type->i_mutex_dir_key#12){++++}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#0: ffff8880615e58d0 (&type->i_mutex_dir_key#12){++++}-{3:3}, at: open_last_lookups fs/namei.c:3561 [inline]
#0: ffff8880615e58d0 (&type->i_mutex_dir_key#12){++++}-{3:3}, at: path_openat+0x7c6/0x3190 fs/namei.c:3794
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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: 16910 Comm: kworker/u4:7 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:apic_wait_icr_idle arch/x86/include/asm/apic.h:459 [inline]
RIP: 0010:arch_irq_work_raise+0x68/0x70 arch/x86/kernel/irq_work.c:32
Code: 00 02 00 00 31 ff e8 c7 6a 56 00 48 81 e3 00 02 00 00 75 07 e8 79 66 56 00 5b c3 e8 72 66 56 00 bf f6 00 00 00 e8 f8 41 0a 00 <5b> c3 cc cc cc cc 66 90 66 0f 1f 00 41 56 53 e8 54 66 56 00 e8 af
RSP: 0018:ffffc9001c947700 EFLAGS: 00000246
RAX: 00000000000000f6 RBX: 0000000000000200 RCX: 000000000000083f
RDX: 0000000000000000 RSI: 00000000000000f6 RDI: 000000000000083f
RBP: 0000000000000000 R08: ffffc9001c947667 R09: 1ffff92003928ecc
R10: dffffc0000000000 R11: fffff52003928ecd R12: 0000000000000001
R13: dffffc0000000000 R14: ffffffff8ce2c0a8 R15: 0000000000000020
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7af5f84fe8 CR3: 000000000cb30000 CR4: 00000000003506f0
Call Trace:
<TASK>
irq_work_queue+0x99/0x140 kernel/irq_work.c:124
__kfence_alloc+0x263/0x3a0 mm/kfence/core.c:1094
kfence_alloc include/linux/kfence.h:129 [inline]
slab_alloc_node mm/slub.c:3481 [inline]
kmem_cache_alloc_node+0x2c0/0x330 mm/slub.c:3540
__alloc_skb+0x108/0x2c0 net/core/skbuff.c:643
alloc_skb include/linux/skbuff.h:1284 [inline]
nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline]
nsim_dev_trap_report_work+0x293/0xb00 drivers/net/netdevsim/dev.c:851
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>
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
syzbot found the following issue on:
HEAD commit: 5fa4793a2d2d Linux 6.6.119
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=16b2f77c580000
kernel config: https://syzkaller.appspot.com/x/.config?x=691a6769a86ac817
dashboard link: https://syzkaller.appspot.com/bug?extid=fb8f78a315b6402af738
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/63699875f1dd/disk-5fa4793a.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/8506652fcb6f/vmlinux-5fa4793a.xz
kernel image: https://storage.googleapis.com/syzbot-assets/1b30ceed1710/bzImage-5fa4793a.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+fb8f78...@syzkaller.appspotmail.com
INFO: task syz.5.2147:15432 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.2147 state:D stack:26224 pid:15432 ppid:6610 flags:0x00004004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
io_schedule+0x80/0xd0 kernel/sched/core.c:9022
folio_wait_bit_common+0x6eb/0xf70 mm/filemap.c:1329
release_metapage+0x97/0x870 fs/jfs/jfs_metapage.c:764
discard_metapage fs/jfs/jfs_metapage.h:88 [inline]
__get_metapage+0xa69/0xfa0 fs/jfs/jfs_metapage.c:644
dtSearch+0x591/0x21b0 fs/jfs/jfs_dtree.c:624
jfs_lookup+0x156/0x380 fs/jfs/namei.c:1459
lookup_open fs/namei.c:3474 [inline]
open_last_lookups fs/namei.c:3564 [inline]
path_openat+0x10b8/0x3190 fs/namei.c:3794
do_filp_open+0x1c5/0x3d0 fs/namei.c:3824
do_sys_openat2+0x12c/0x1c0 fs/open.c:1421
do_sys_open fs/open.c:1436 [inline]
__do_sys_openat fs/open.c:1452 [inline]
__se_sys_openat fs/open.c:1447 [inline]
__x64_sys_openat+0x139/0x160 fs/open.c:1447
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: 0033:0x7f008278f749
RSP: 002b:00007f00836ea038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f00829e6090 RCX: 00007f008278f749
RDX: 0000000000040042 RSI: 0000200000000240 RDI: ffffffffffffff9c
RBP: 00007f0082813f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f00829e6128 R14: 00007f00829e6090 R15: 00007fff2980cf58
</TASK>
Showing all locks held in the system:
2 locks held by kworker/u4:0/11:
#0: ffff888017871538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888017871538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffff8880b8e289c0 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:189 [inline]
#1: ffff8880b8e289c0 (psi_seq){-.-.}-{0:0}, at: __schedule+0x20ee/0x44d0 kernel/sched/core.c:6694
2 locks held by kworker/1:0/23:
#0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc900001d7d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc900001d7d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
1 lock held by khungtaskd/29:
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
3 locks held by kworker/u4:11/3479:
#0: ffff888141e4e938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888141e4e938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc9000cdc7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc9000cdc7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff88805f0e60e0 (&type->s_umount_key#69){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
2 locks held by getty/5533:
#0: ffff88814e3800a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217
2 locks held by udevd/10085:
#0: ffff8880b8e3c018 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:566
#1: ffff8880b8e289c0 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:189 [inline]
#1: ffff8880b8e289c0 (psi_seq){-.-.}-{0:0}, at: __schedule+0x20ee/0x44d0 kernel/sched/core.c:6694
3 locks held by kworker/1:7/12924:
#0: ffff8881400fa938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff8881400fa938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc9000b76fd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc9000b76fd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff888024a64190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:995 [inline]
#2: ffff888024a64190 (&dev->mutex){....}-{3:3}, at: hub_event+0x185/0x49c0 drivers/usb/core/hub.c:5861
1 lock held by syz-executor/14044:
#0: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline]
#0: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x448/0x830 kernel/rcu/tree_exp.h:1004
1 lock held by syz-executor/14162:
1 lock held by syz.5.2147/15432:
#0: ffff8880615e58d0 (&type->i_mutex_dir_key#12){++++}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#0: ffff8880615e58d0 (&type->i_mutex_dir_key#12){++++}-{3:3}, at: open_last_lookups fs/namei.c:3561 [inline]
#0: ffff8880615e58d0 (&type->i_mutex_dir_key#12){++++}-{3:3}, at: path_openat+0x7c6/0x3190 fs/namei.c:3794
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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: 16910 Comm: kworker/u4:7 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:apic_wait_icr_idle arch/x86/include/asm/apic.h:459 [inline]
RIP: 0010:arch_irq_work_raise+0x68/0x70 arch/x86/kernel/irq_work.c:32
Code: 00 02 00 00 31 ff e8 c7 6a 56 00 48 81 e3 00 02 00 00 75 07 e8 79 66 56 00 5b c3 e8 72 66 56 00 bf f6 00 00 00 e8 f8 41 0a 00 <5b> c3 cc cc cc cc 66 90 66 0f 1f 00 41 56 53 e8 54 66 56 00 e8 af
RSP: 0018:ffffc9001c947700 EFLAGS: 00000246
RAX: 00000000000000f6 RBX: 0000000000000200 RCX: 000000000000083f
RDX: 0000000000000000 RSI: 00000000000000f6 RDI: 000000000000083f
RBP: 0000000000000000 R08: ffffc9001c947667 R09: 1ffff92003928ecc
R10: dffffc0000000000 R11: fffff52003928ecd R12: 0000000000000001
R13: dffffc0000000000 R14: ffffffff8ce2c0a8 R15: 0000000000000020
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7af5f84fe8 CR3: 000000000cb30000 CR4: 00000000003506f0
Call Trace:
<TASK>
irq_work_queue+0x99/0x140 kernel/irq_work.c:124
__kfence_alloc+0x263/0x3a0 mm/kfence/core.c:1094
kfence_alloc include/linux/kfence.h:129 [inline]
slab_alloc_node mm/slub.c:3481 [inline]
kmem_cache_alloc_node+0x2c0/0x330 mm/slub.c:3540
__alloc_skb+0x108/0x2c0 net/core/skbuff.c:643
alloc_skb include/linux/skbuff.h:1284 [inline]
nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline]
nsim_dev_trap_report_work+0x293/0xb00 drivers/net/netdevsim/dev.c:851
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>
---
This report is generated by a bot. It may contain errors.
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If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want to overwrite report's subsystems, reply with:
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If you want to undo deduplication, reply with:
#syz undup
syzbot
Dec 21, 2025, 11:47:34 PM (3 days ago) Dec 21
to syzkaller...@googlegroups.com
syzbot has found a reproducer for the following issue on:
HEAD commit: 5fa4793a2d2d Linux 6.6.119
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1645db1a580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1724c3c2580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/63699875f1dd/disk-5fa4793a.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/8506652fcb6f/vmlinux-5fa4793a.xz
kernel image: https://storage.googleapis.com/syzbot-assets/1b30ceed1710/bzImage-5fa4793a.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/b7a883f8651b/mount_1.gz
fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=104ff77c580000)
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+fb8f78...@syzkaller.appspotmail.com
INFO: task syz.0.17:5945 blocked for more than 143 seconds.
RSP: 002b:00007ffc97a3b978 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f29b29e5fa0 RCX: 00007f29b278f749
3 locks held by kworker/u4:3/49:
#0: ffff888140069d38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888140069d38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc90000ba7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc90000ba7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff88802c9ca0e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
3 locks held by kworker/u4:5/991:
#0: ffff888140069d38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888140069d38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc9000416fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc9000416fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff8880263b80e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
3 locks held by kworker/u4:6/1120:
#0: ffff888140069d38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888140069d38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc9000418fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc9000418fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff88807bfcc0e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
3 locks held by kworker/u4:7/2903:
#0: ffff888140069d38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888140069d38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc9000bb27d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc9000bb27d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff888024c960e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
3 locks held by kworker/u4:8/2948:
#0: ffff888140069d38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888140069d38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc9000bf47d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc9000bf47d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff88807c7a20e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
3 locks held by kworker/u4:9/3549:
#0: ffff888140069d38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888140069d38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc9000cc87d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc9000cc87d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff888026ae80e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
2 locks held by getty/5528:
#0: ffff88814cede0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#0: ffff8880601533d0 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#0: ffff8880601533d0 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: open_last_lookups fs/namei.c:3561 [inline]
#0: ffff8880601533d0 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: path_openat+0x7c6/0x3190 fs/namei.c:3794
1 lock held by syz.1.18/5968:
#0: ffff888060238ed0 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#0: ffff888060238ed0 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: open_last_lookups fs/namei.c:3561 [inline]
#0: ffff888060238ed0 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: path_openat+0x7c6/0x3190 fs/namei.c:3794
1 lock held by syz.2.19/5991:
#0: ffff88806017bd10 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#0: ffff88806017bd10 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: open_last_lookups fs/namei.c:3561 [inline]
#0: ffff88806017bd10 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: path_openat+0x7c6/0x3190 fs/namei.c:3794
1 lock held by syz.3.20/6018:
#0: ffff8880600b2150 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#0: ffff8880600b2150 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: open_last_lookups fs/namei.c:3561 [inline]
#0: ffff8880600b2150 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: path_openat+0x7c6/0x3190 fs/namei.c:3794
1 lock held by syz.4.21/6046:
#0: ffff88806023b3d0 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#0: ffff88806023b3d0 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: open_last_lookups fs/namei.c:3561 [inline]
#0: ffff88806023b3d0 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: path_openat+0x7c6/0x3190 fs/namei.c:3794
3 locks held by kworker/u4:11/6073:
#0: ffff888140069d38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888140069d38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc90003fe7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc90003fe7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff888058b6e0e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
1 lock held by syz.5.22/6074:
#0: ffff8880600b58d0 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#0: ffff8880600b58d0 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: open_last_lookups fs/namei.c:3561 [inline]
#0: ffff8880600b58d0 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: path_openat+0x7c6/0x3190 fs/namei.c:3794
3 locks held by kworker/u4:12/6075:
#0: ffff888140069d38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888140069d38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc900038d7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc900038d7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff8880551380e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
1 lock held by syz.6.23/6108:
#0: ffff888073c63d10 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#0: ffff888073c63d10 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: open_last_lookups fs/namei.c:3561 [inline]
#0: ffff888073c63d10 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: path_openat+0x7c6/0x3190 fs/namei.c:3794
3 locks held by kworker/u4:13/6109:
#0: ffff888140069d38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888140069d38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc900041afd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc900041afd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff888076c680e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
1 lock held by syz.7.24/6137:
#0: ffff888073f92150 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#0: ffff888073f92150 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: open_last_lookups fs/namei.c:3561 [inline]
#0: ffff888073f92150 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: path_openat+0x7c6/0x3190 fs/namei.c:3794
1 lock held by syz.8.25/6165:
#0: ffff888073f97490 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#0: ffff888073f97490 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: open_last_lookups fs/namei.c:3561 [inline]
#0: ffff888073f97490 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: path_openat+0x7c6/0x3190 fs/namei.c:3794
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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: 6019 Comm: kworker/u4:10 Not tainted syzkaller #0
RIP: 0010:arch_irqs_disabled_flags arch/x86/include/asm/irqflags.h:126 [inline]
RIP: 0010:lockdep_hardirqs_on_prepare+0xe8/0x760 kernel/locking/lockdep.c:4340
Code: b4 e9 96 48 c1 e8 03 0f b6 04 10 84 c0 0f 85 0b 05 00 00 83 3d 08 f2 82 15 00 75 6c 48 c7 44 24 40 00 00 00 00 9c 8f 44 24 40 <f6> 44 24 41 02 0f 85 87 03 00 00 48 c7 c0 80 b4 e9 96 48 c1 e8 03
RSP: 0018:ffffc90003677960 EFLAGS: 00000046
RAX: 0000000000000004 RBX: 1ffff920006cef30 RCX: ffffffff96e9b403
RDX: dffffc0000000000 RSI: ffffffff8afc6f60 RDI: ffffffff8afc6f20
RBP: ffffc90003677a08 R08: ffffffff8e4a212f R09: 1ffffffff1c94425
R10: dffffc0000000000 R11: fffffbfff1c94426 R12: ffffffff8a302e61
R13: dffffc0000000000 R14: dffffc0000000000 R15: 1ffff920006cef44
Call Trace:
<TASK>
trace_hardirqs_on+0x28/0x40 kernel/trace/trace_preemptirq.c:61
__local_bh_enable_ip+0x12e/0x1c0 kernel/softirq.c:411
spin_unlock_bh include/linux/spinlock.h:396 [inline]
batadv_nc_purge_paths+0x311/0x3a0 net/batman-adv/network-coding.c:471
batadv_nc_worker+0x328/0x610 net/batman-adv/network-coding.c:720
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
HEAD commit: 5fa4793a2d2d Linux 6.6.119
git tree: linux-6.6.y
kernel config: https://syzkaller.appspot.com/x/.config?x=691a6769a86ac817
dashboard link: https://syzkaller.appspot.com/bug?extid=fb8f78a315b6402af738
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16b15392580000
dashboard link: https://syzkaller.appspot.com/bug?extid=fb8f78a315b6402af738
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1724c3c2580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/63699875f1dd/disk-5fa4793a.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/8506652fcb6f/vmlinux-5fa4793a.xz
kernel image: https://storage.googleapis.com/syzbot-assets/1b30ceed1710/bzImage-5fa4793a.xz
fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=104ff77c580000)
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+fb8f78...@syzkaller.appspotmail.com
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.17 state:D stack:25160 pid:5945 ppid:5896 flags:0x00004004
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
io_schedule+0x80/0xd0 kernel/sched/core.c:9022
folio_wait_bit_common+0x6eb/0xf70 mm/filemap.c:1329
release_metapage+0x97/0x870 fs/jfs/jfs_metapage.c:764
discard_metapage fs/jfs/jfs_metapage.h:88 [inline]
__get_metapage+0xa69/0xfa0 fs/jfs/jfs_metapage.c:644
dtSearch+0x591/0x21b0 fs/jfs/jfs_dtree.c:624
jfs_lookup+0x156/0x380 fs/jfs/namei.c:1459
lookup_open fs/namei.c:3474 [inline]
open_last_lookups fs/namei.c:3564 [inline]
path_openat+0x10b8/0x3190 fs/namei.c:3794
do_filp_open+0x1c5/0x3d0 fs/namei.c:3824
do_sys_openat2+0x12c/0x1c0 fs/open.c:1421
do_sys_open fs/open.c:1436 [inline]
__do_sys_openat fs/open.c:1452 [inline]
__se_sys_openat fs/open.c:1447 [inline]
__x64_sys_openat+0x139/0x160 fs/open.c:1447
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: 0033:0x7f29b278f749
<TASK>
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
io_schedule+0x80/0xd0 kernel/sched/core.c:9022
folio_wait_bit_common+0x6eb/0xf70 mm/filemap.c:1329
release_metapage+0x97/0x870 fs/jfs/jfs_metapage.c:764
discard_metapage fs/jfs/jfs_metapage.h:88 [inline]
__get_metapage+0xa69/0xfa0 fs/jfs/jfs_metapage.c:644
dtSearch+0x591/0x21b0 fs/jfs/jfs_dtree.c:624
jfs_lookup+0x156/0x380 fs/jfs/namei.c:1459
lookup_open fs/namei.c:3474 [inline]
open_last_lookups fs/namei.c:3564 [inline]
path_openat+0x10b8/0x3190 fs/namei.c:3794
do_filp_open+0x1c5/0x3d0 fs/namei.c:3824
do_sys_openat2+0x12c/0x1c0 fs/open.c:1421
do_sys_open fs/open.c:1436 [inline]
__do_sys_openat fs/open.c:1452 [inline]
__se_sys_openat fs/open.c:1447 [inline]
__x64_sys_openat+0x139/0x160 fs/open.c:1447
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
RSP: 002b:00007ffc97a3b978 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f29b29e5fa0 RCX: 00007f29b278f749
RDX: 0000000000040042 RSI: 0000200000000240 RDI: ffffffffffffff9c
RBP: 00007f29b2813f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f29b29e5fa0 R14: 00007f29b29e5fa0 R15: 0000000000000004
</TASK>
Showing all locks held in the system:
Showing all locks held in the system:
1 lock held by khungtaskd/29:
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
2 locks held by kworker/u4:2/42:
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
3 locks held by kworker/u4:3/49:
#0: ffff888140069d38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888140069d38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc90000ba7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc90000ba7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff88802c9ca0e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
3 locks held by kworker/u4:5/991:
#0: ffff888140069d38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888140069d38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc9000416fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc9000416fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff8880263b80e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
3 locks held by kworker/u4:6/1120:
#0: ffff888140069d38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888140069d38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc9000418fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc9000418fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff88807bfcc0e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
3 locks held by kworker/u4:7/2903:
#0: ffff888140069d38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888140069d38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc9000bb27d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc9000bb27d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff888024c960e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
3 locks held by kworker/u4:8/2948:
#0: ffff888140069d38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888140069d38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc9000bf47d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc9000bf47d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff88807c7a20e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
3 locks held by kworker/u4:9/3549:
#0: ffff888140069d38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888140069d38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc9000cc87d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc9000cc87d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff888026ae80e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
2 locks held by getty/5528:
#0: ffff88814cede0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217
1 lock held by syz.0.17/5945:
#0: ffff8880601533d0 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#0: ffff8880601533d0 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: open_last_lookups fs/namei.c:3561 [inline]
#0: ffff8880601533d0 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: path_openat+0x7c6/0x3190 fs/namei.c:3794
1 lock held by syz.1.18/5968:
#0: ffff888060238ed0 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#0: ffff888060238ed0 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: open_last_lookups fs/namei.c:3561 [inline]
#0: ffff888060238ed0 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: path_openat+0x7c6/0x3190 fs/namei.c:3794
1 lock held by syz.2.19/5991:
#0: ffff88806017bd10 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#0: ffff88806017bd10 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: open_last_lookups fs/namei.c:3561 [inline]
#0: ffff88806017bd10 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: path_openat+0x7c6/0x3190 fs/namei.c:3794
1 lock held by syz.3.20/6018:
#0: ffff8880600b2150 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#0: ffff8880600b2150 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: open_last_lookups fs/namei.c:3561 [inline]
#0: ffff8880600b2150 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: path_openat+0x7c6/0x3190 fs/namei.c:3794
1 lock held by syz.4.21/6046:
#0: ffff88806023b3d0 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#0: ffff88806023b3d0 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: open_last_lookups fs/namei.c:3561 [inline]
#0: ffff88806023b3d0 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: path_openat+0x7c6/0x3190 fs/namei.c:3794
3 locks held by kworker/u4:11/6073:
#0: ffff888140069d38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888140069d38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc90003fe7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc90003fe7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff888058b6e0e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
1 lock held by syz.5.22/6074:
#0: ffff8880600b58d0 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#0: ffff8880600b58d0 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: open_last_lookups fs/namei.c:3561 [inline]
#0: ffff8880600b58d0 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: path_openat+0x7c6/0x3190 fs/namei.c:3794
3 locks held by kworker/u4:12/6075:
#0: ffff888140069d38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888140069d38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc900038d7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc900038d7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff8880551380e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
1 lock held by syz.6.23/6108:
#0: ffff888073c63d10 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#0: ffff888073c63d10 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: open_last_lookups fs/namei.c:3561 [inline]
#0: ffff888073c63d10 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: path_openat+0x7c6/0x3190 fs/namei.c:3794
3 locks held by kworker/u4:13/6109:
#0: ffff888140069d38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888140069d38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc900041afd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc900041afd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff888076c680e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
1 lock held by syz.7.24/6137:
#0: ffff888073f92150 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#0: ffff888073f92150 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: open_last_lookups fs/namei.c:3561 [inline]
#0: ffff888073f92150 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: path_openat+0x7c6/0x3190 fs/namei.c:3794
1 lock held by syz.8.25/6165:
#0: ffff888073f97490 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#0: ffff888073f97490 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: open_last_lookups fs/namei.c:3561 [inline]
#0: ffff888073f97490 (&type->i_mutex_dir_key#9){+.+.}-{3:3}, at: path_openat+0x7c6/0x3190 fs/namei.c:3794
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: bat_events batadv_nc_worker
RIP: 0010:arch_irqs_disabled_flags arch/x86/include/asm/irqflags.h:126 [inline]
RIP: 0010:lockdep_hardirqs_on_prepare+0xe8/0x760 kernel/locking/lockdep.c:4340
Code: b4 e9 96 48 c1 e8 03 0f b6 04 10 84 c0 0f 85 0b 05 00 00 83 3d 08 f2 82 15 00 75 6c 48 c7 44 24 40 00 00 00 00 9c 8f 44 24 40 <f6> 44 24 41 02 0f 85 87 03 00 00 48 c7 c0 80 b4 e9 96 48 c1 e8 03
RSP: 0018:ffffc90003677960 EFLAGS: 00000046
RAX: 0000000000000004 RBX: 1ffff920006cef30 RCX: ffffffff96e9b403
RDX: dffffc0000000000 RSI: ffffffff8afc6f60 RDI: ffffffff8afc6f20
RBP: ffffc90003677a08 R08: ffffffff8e4a212f R09: 1ffffffff1c94425
R10: dffffc0000000000 R11: fffffbfff1c94426 R12: ffffffff8a302e61
R13: dffffc0000000000 R14: dffffc0000000000 R15: 1ffff920006cef44
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055f0ca399a38 CR3: 000000000cb30000 CR4: 00000000003506f0
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Call Trace:
<TASK>
trace_hardirqs_on+0x28/0x40 kernel/trace/trace_preemptirq.c:61
__local_bh_enable_ip+0x12e/0x1c0 kernel/softirq.c:411
spin_unlock_bh include/linux/spinlock.h:396 [inline]
batadv_nc_purge_paths+0x311/0x3a0 net/batman-adv/network-coding.c:471
batadv_nc_worker+0x328/0x610 net/batman-adv/network-coding.c:720
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>
---
If you want syzbot to run the reproducer, reply with:
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>
---
#syz test: git://repo/address.git branch-or-commit-hash
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