INFO: task syz-executor:6901 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21736 pid:6901 ppid:1 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168 gfs2_gl_hash_clear+0x1b4/0x450 fs/gfs2/glock.c:2256 gfs2_put_super+0x8bb/0x930 fs/gfs2/super.c:650 generic_shutdown_super+0x134/0x2b0 fs/super.c:693 kill_block_super+0x44/0x90 fs/super.c:1660 deactivate_locked_super+0x97/0x100 fs/super.c:481 cleanup_mnt+0x43b/0x4d0 fs/namespace.c:1259 task_work_run+0x1d4/0x260 kernel/task_work.c:245 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fb08ed9da57 RSP: 002b:00007ffe9de827b8 EFLAGS: 00000206 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000064 RCX: 00007fb08ed9da57 RDX: 0000000000000200 RSI: 0000000000000009 RDI: 00007ffe9de83960 RBP: 00007fb08ee32048 R08: 00000000000105a0 R09: 00000000ffffffff R10: 0000000000000100 R11: 0000000000000206 R12: 00007ffe9de83960 R13: 00007fb08ee32048 R14: 00005555860924e8 R15: 00007ffe9de84a30 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8d1320a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8d1320a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8d1320a0 (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: 2 locks held by kworker/u4:7/2917: 1 lock held by dhcpcd/5432: #0: ffffffff8e3c1988 (rtnl_mutex){+.+.}-{3:3}, at: devinet_ioctl+0x30c/0x1c40 net/ipv4/devinet.c:1101 2 locks held by getty/5526: #0: ffff8880323fa0a0 (&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+0x433/0x1390 drivers/tty/n_tty.c:2217 2 locks held by kworker/0:4/5810: #0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730 #1: ffffc9000492fd00 ((work_completion)(&m->mpeg_thread)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #1: ffffc9000492fd00 ((work_completion)(&m->mpeg_thread)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730 2 locks held by kworker/1:6/6495: #0: ffff888017c72538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #0: ffff888017c72538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730 #1: ffffc900033b7d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #1: ffffc900033b7d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730 1 lock held by syz-executor/6901: #0: ffff88801c3a00e0 (&type->s_umount_key#99){++++}-{3:3}, at: __super_lock fs/super.c:56 [inline] #0: ffff88801c3a00e0 (&type->s_umount_key#99){++++}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff88801c3a00e0 (&type->s_umount_key#99){++++}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513 1 lock held by syz.9.421/9151: #0: ffff88801c3a00e0 (&type->s_umount_key#99){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline] #0: ffff88801c3a00e0 (&type->s_umount_key#99){++++}-{3:3}, at: super_lock+0x17f/0x3a0 fs/super.c:117 2 locks held by syz-executor/10460: #0: ffffffff8e3c1988 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline] #0: ffffffff8e3c1988 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x41/0x1c0 drivers/net/tun.c:3511 #1: ffffffff8d137a78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline] #1: ffffffff8d137a78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x306/0x880 kernel/rcu/tree_exp.h:1004 1 lock held by syz-executor/10944: #0: ffffffff8e3c1988 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline] #0: ffffffff8e3c1988 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x811/0xfa0 net/core/rtnetlink.c:6469 1 lock held by syz.3.681/11056: #0: ffffffff8e3c1988 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline] #0: ffffffff8e3c1988 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x811/0xfa0 net/core/rtnetlink.c:6469 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a6/0x3e0 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+0xf3d/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 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 11 Comm: kworker/u4:0 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: bat_events batadv_nc_worker RIP: 0010:hlock_class kernel/locking/lockdep.c:-1 [inline] RIP: 0010:__lock_acquire+0x106d/0x7d40 kernel/locking/lockdep.c:5133 Code: 7c 24 60 00 0f 84 f0 01 00 00 48 8b 84 24 90 00 00 00 48 8d 58 f8 48 89 d8 48 c1 e8 03 42 0f b6 04 00 84 c0 0f 85 da 5f 00 00 <8b> 03 89 c3 81 e3 ff 1f 00 00 c1 e8 03 25 f8 03 00 00 48 8d b8 00 RSP: 0018:ffffc90000107700 EFLAGS: 00000046 RAX: 0000000000000000 RBX: ffff88801a274728 RCX: 000000008b939605 RDX: 00000000bfbb9660 RSI: 00000000b9d8e7a3 RDI: ffffffff911c35d8 RBP: ffffc90000107948 R08: dffffc0000000000 R09: 1ffffffff22386bb R10: dffffc0000000000 R11: fffffbfff22386bc R12: 00000000c4603b5a R13: ffff88801a273c00 R14: 00000000d4d1d18b R15: ffff88801a274750 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c39f8e9 CR3: 0000000032535000 CR4: 00000000003506e0 Call Trace: lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x36/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] batadv_nc_purge_paths+0xe7/0x3a0 net/batman-adv/network-coding.c:442 batadv_nc_worker+0x328/0x610 net/batman-adv/network-coding.c:720 process_one_work kernel/workqueue.c:2653 [inline] process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811 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