INFO: task syz.7.304:7868[ 425.978812][ T37] INFO: task syz.7.304:7868 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.7.304 state:D stack:19896 pid:7868 tgid:7866 ppid:7226 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5387 [inline] __schedule+0x1681/0x54c0 kernel/sched/core.c:7188 __schedule_loop kernel/sched/core.c:7267 [inline] schedule+0x164/0x360 kernel/sched/core.c:7282 __wait_on_freeing_inode+0x214/0x3b0 fs/inode.c:2554 find_inode+0x311/0x550 fs/inode.c:1061 inode_insert5+0x127/0x5e0 fs/inode.c:1310 insert_inode_locked4+0x74/0xc0 fs/inode.c:1889 nilfs_insert_inode_locked fs/nilfs2/inode.c:297 [inline] nilfs_new_inode+0x4db/0x800 fs/nilfs2/inode.c:351 nilfs_mkdir+0x114/0x340 fs/nilfs2/namei.c:234 vfs_mkdir+0x40b/0x630 fs/namei.c:5261 filename_mkdirat+0x289/0x520 fs/namei.c:5294 __do_sys_mkdirat fs/namei.c:5315 [inline] __se_sys_mkdirat+0x35/0x150 fs/namei.c:5312 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f007d9ebc47 RSP: 002b:00007f007bc3de58 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007f007bc3dee0 RCX: 00007f007d9ebc47 RDX: 00000000000001ff RSI: 000020000001fc00 RDI: 00000000ffffff9c RBP: 0000200000000b00 R08: 0000200000000140 R09: 0000000000000000 R10: 0000200000000b00 R11: 0000000000000246 R12: 000020000001fc00 R13: 00007f007bc3dea0 R14: 0000000000000000 R15: 0000000000000000 INFO: task segctord:7869 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:segctord state:D stack:26432 pid:7869 tgid:7869 ppid:2 task_flags:0x200040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5387 [inline] __schedule+0x1681/0x54c0 kernel/sched/core.c:7188 __schedule_loop kernel/sched/core.c:7267 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7563 rwbase_write_lock+0x3da/0x730 kernel/locking/rwbase_rt.c:273 nilfs_transaction_lock+0x252/0x4c0 fs/nilfs2/segment.c:357 nilfs_segctor_thread_construct fs/nilfs2/segment.c:2569 [inline] nilfs_segctor_thread+0x6b5/0xdc0 fs/nilfs2/segment.c:2684 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Showing all locks held in the system: 3 locks held by kworker/u8:1/13: #0: ffff888064d73138 ((wq_completion)loop3){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline] #0: ffff888064d73138 ((wq_completion)loop3){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385 #1: ffffc90000127c40 ((work_completion)(&worker->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline] #1: ffffc90000127c40 ((work_completion)(&worker->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385 #2: ffff8880266d8160 (&lo->lo_work_lock){+.+.}-{3:3}, at: spin_lock_irq include/linux/spinlock_rt.h:96 [inline] #2: ffff8880266d8160 (&lo->lo_work_lock){+.+.}-{3:3}, at: loop_process_work+0x125/0x11b0 drivers/block/loop.c:1953 10 locks held by ktimers/1/29: 1 lock held by khungtaskd/37: #0: ffffffff8dfc8140 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8dfc8140 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8dfc8140 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5350: #0: ffff88803768b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003cbe2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13a0 drivers/tty/n_tty.c:2211 3 locks held by kworker/0:7/7645: #0: ffff88801a037938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline] #0: ffff88801a037938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385 #1: ffffc90004537c40 ((work_completion)(&sci->sc_iput_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline] #1: ffffc90004537c40 ((work_completion)(&sci->sc_iput_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385 #2: ffff888057128770 (sb_internal#5){.+.+}-{0:0}, at: nilfs_evict_inode+0x167/0x4b0 fs/nilfs2/inode.c:868 4 locks held by syz.7.304/7868: #0: ffff888057128480 (sb_writers#27){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff8880635bcc50 (&type->i_mutex_dir_key#20/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1074 [inline] #1: ffff8880635bcc50 (&type->i_mutex_dir_key#20/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2914 [inline] #1: ffff8880635bcc50 (&type->i_mutex_dir_key#20/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2938 [inline] #1: ffff8880635bcc50 (&type->i_mutex_dir_key#20/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:4950 #2: ffff888057128770 (sb_internal#5){.+.+}-{0:0}, at: nilfs_mkdir+0xd6/0x340 fs/nilfs2/namei.c:228 #3: ffff888039f7c2b0 (&nilfs->ns_segctor_sem){++++}-{4:4}, at: nilfs_transaction_begin+0x364/0x710 fs/nilfs2/segment.c:221 1 lock held by segctord/7869: #0: ffff888039f7c2b0 (&nilfs->ns_segctor_sem){++++}-{4:4}, at: nilfs_transaction_lock+0x252/0x4c0 fs/nilfs2/segment.c:357 2 locks held by syz-executor/8346: #0: ffff88805f504f80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:500 [inline] #0: ffff88805f504f80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x5a0 net/bluetooth/hci_core.c:2716 #1: ffff88805f5040b0 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x640/0x10e0 net/bluetooth/hci_sync.c:5356 3 locks held by syz.0.492/9786: 7 locks held by syz.3.491/9791: 4 locks held by syz.3.491/9799: 1 lock held by syz.4.495/9801: 3 locks held by cmp/9802: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: 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:162 [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:353 [inline] watchdog+0xfd3/0x1030 kernel/hung_task.c:561 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 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: 29 Comm: ktimers/1 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:check_wait_context kernel/locking/lockdep.c:4869 [inline] RIP: 0010:__lock_acquire+0x46a/0x2cf0 kernel/locking/lockdep.c:5187 Code: 0b 00 00 41 8d 4c 24 ff 83 f9 ff 41 bd ff ff ff ff 44 0f 4c e9 41 ff c5 41 8d 5c 24 01 49 ff cc 89 d9 83 c1 fe 78 40 45 89 e7 <41> 81 e7 ff ff ff 7f 83 f9 31 73 1d 4b 8d 0c bf 41 8b 8c ce 18 0c RSP: 0000:ffffc90000a3edb0 EFLAGS: 00000017 RAX: 000000000002000b RBX: 0000000000000007 RCX: 0000000000000005 RDX: 0000000000000003 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff88801daacba8 R08: ffffffff8176d226 R09: ffffffff8dfc8140 R10: ffffc90000a3f0b8 R11: ffffffff81af8dc0 R12: 0000000000000005 R13: 0000000000000000 R14: ffff88801daabd80 R15: 0000000000000005 FS: 0000000000000000(0000) GS:ffff88812627c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc26d0ee000 CR3: 0000000064780000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 rcu_lock_acquire include/linux/rcupdate.h:300 [inline] rcu_read_lock include/linux/rcupdate.h:838 [inline] class_rcu_constructor include/linux/rcupdate.h:1181 [inline] unwind_next_frame+0xc3/0x2550 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4569 [inline] slab_alloc_node mm/slub.c:4898 [inline] kmem_cache_alloc_node_noprof+0x22a/0x6e0 mm/slub.c:4950 __alloc_skb+0x1d0/0x7d0 net/core/skbuff.c:702 alloc_skb include/linux/skbuff.h:1383 [inline] nlmsg_new include/net/netlink.h:1055 [inline] __neigh_notify+0x15c/0x310 net/core/neighbour.c:3573 neigh_notify net/core/neighbour.c:3595 [inline] neigh_cleanup_and_release+0xc2/0x2d0 net/core/neighbour.c:119 neigh_remove_one+0x46d/0x4c0 net/core/neighbour.c:249 neigh_forced_gc net/core/neighbour.c:280 [inline] neigh_alloc net/core/neighbour.c:512 [inline] ___neigh_create+0x49f/0x2350 net/core/neighbour.c:655 ip6_finish_output2+0x729/0x1430 net/ipv6/ip6_output.c:128 NF_HOOK_COND include/linux/netfilter.h:307 [inline] ip6_output+0x340/0x550 net/ipv6/ip6_output.c:246 dst_output include/net/dst.h:470 [inline] NF_HOOK include/linux/netfilter.h:318 [inline] ndisc_send_skb+0xd0b/0x1670 net/ipv6/ndisc.c:512 addrconf_rs_timer+0x395/0x6d0 net/ipv6/addrconf.c:4049 call_timer_fn+0x192/0x5e0 kernel/time/timer.c:1748 expire_timers kernel/time/timer.c:1799 [inline] __run_timers kernel/time/timer.c:2374 [inline] __run_timer_base+0x6a3/0x9f0 kernel/time/timer.c:2386 run_timer_base kernel/time/timer.c:2395 [inline] run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2405 handle_softirqs+0x1de/0x6d0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] run_ktimerd+0x69/0x100 kernel/softirq.c:1151 smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245