INFO: task syz-executor:5837 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:21288 pid:5837 tgid:5837 ppid:1 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 bit_wait+0x11/0xd0 kernel/sched/wait_bit.c:240 __wait_on_bit+0xb9/0x310 kernel/sched/wait_bit.c:52 out_of_line_wait_on_bit+0x123/0x170 kernel/sched/wait_bit.c:67 wait_on_bit include/linux/wait_bit.h:77 [inline] gfs2_glock_wait+0xbd/0x2a0 fs/gfs2/glock.c:1335 gfs2_glock_nq_init fs/gfs2/glock.h:252 [inline] __gfs2_lookup+0x117/0x270 fs/gfs2/inode.c:984 __lookup_slow+0x297/0x3d0 fs/namei.c:1816 lookup_slow+0x53/0x70 fs/namei.c:1833 walk_component+0x2d2/0x400 fs/namei.c:2151 lookup_last fs/namei.c:2652 [inline] path_lookupat+0x163/0x430 fs/namei.c:2676 filename_lookup+0x212/0x570 fs/namei.c:2705 user_path_at+0x3a/0x60 fs/namei.c:3215 ksys_umount fs/namespace.c:2061 [inline] __do_sys_umount fs/namespace.c:2069 [inline] __se_sys_umount fs/namespace.c:2067 [inline] __x64_sys_umount+0xee/0x160 fs/namespace.c:2067 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: 0033:0x7fb0cff901f7 RSP: 002b:00007ffea9f6bec8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: ffffffffffffffda RBX: 00007fb0d0011d7d RCX: 00007fb0cff901f7 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffea9f6bf80 RBP: 00007ffea9f6bf80 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffea9f6d070 R13: 00007fb0d0011d7d R14: 000000000003da0c R15: 00007ffea9f6f230 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e13d2e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13d2e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e13d2e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5580: #0: ffff8880338750a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900036bc2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 2 locks held by syz-executor/5821: #0: ffff888051aba0e0 (&type->s_umount_key#57){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff888051aba0e0 (&type->s_umount_key#57){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff888051aba0e0 (&type->s_umount_key#57){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505 #1: ffffffff8e142c40 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3820 1 lock held by syz-executor/5837: #0: ffff88804e0d50c8 (&type->i_mutex_dir_key#17){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:995 [inline] #0: ffff88804e0d50c8 (&type->i_mutex_dir_key#17){++++}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1832 4 locks held by kworker/u8:10/6368: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline] watchdog+0xf60/0xfa0 kernel/hung_task.c:495 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 6104 Comm: kworker/u8:9 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:hlock_class kernel/locking/lockdep.c:234 [inline] RIP: 0010:lookup_chain_cache_add kernel/locking/lockdep.c:3820 [inline] RIP: 0010:validate_chain+0x52/0x2140 kernel/locking/lockdep.c:3876 Code: c1 81 e1 00 80 04 00 81 f9 00 00 04 00 0f 85 61 02 00 00 41 89 d4 49 89 f6 25 ff 1f 00 00 48 0f a3 05 f2 1a fb 11 48 89 3c 24 <72> 36 83 3d 65 aa fe 17 00 75 2d 90 e8 9d 7f ef 02 85 c0 74 22 83 RSP: 0018:ffffc900051aeff8 EFLAGS: 00000007 RAX: 0000000000000027 RBX: 0000000000000004 RCX: 0000000000040000 RDX: 0000000000000000 RSI: ffff88802bb98bd0 RDI: ffff88802bb98000 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8218e41b R10: dffffc0000000000 R11: fffffbfff1f3c22f R12: 0000000000000000 R13: ffff88802bb98b30 R14: ffff88802bb98bd0 R15: 9e9057aa08d8ba13 FS: 0000000000000000(0000) GS:ffff888125e0c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fff96217000 CR3: 00000000271ad000 CR4: 0000000000350ef0 Call Trace: __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 seqcount_lockdep_reader_access+0xee/0x180 include/linux/seqlock.h:72 read_seqbegin include/linux/seqlock.h:836 [inline] zone_span_seqbegin include/linux/memory_hotplug.h:103 [inline] page_outside_zone_boundaries mm/page_alloc.c:585 [inline] bad_range+0x8b/0x2c0 mm/page_alloc.c:604 rmqueue mm/page_alloc.c:3357 [inline] get_page_from_freelist+0x2342/0x2440 mm/page_alloc.c:3881 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5183 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:3039 [inline] allocate_slab+0x96/0x3a0 mm/slub.c:3212 new_slab mm/slub.c:3266 [inline] ___slab_alloc+0xe94/0x18a0 mm/slub.c:4636 __slab_alloc+0x65/0x100 mm/slub.c:4755 __slab_alloc_node mm/slub.c:4831 [inline] slab_alloc_node mm/slub.c:5253 [inline] __do_kmalloc_node mm/slub.c:5626 [inline] __kmalloc_node_track_caller_noprof+0x5c7/0x800 mm/slub.c:5736 kmalloc_reserve+0x136/0x290 net/core/skbuff.c:601 __alloc_skb+0x142/0x2d0 net/core/skbuff.c:670 alloc_skb include/linux/skbuff.h:1383 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:763 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:820 [inline] nsim_dev_trap_report_work+0x29a/0xb80 drivers/net/netdevsim/dev.c:866 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245