INFO: task syz.3.1837:24891 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.1837 state:D stack:21792 pid:24891 tgid:24888 ppid:21245 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x1553/0x5240 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7289 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760 __rwbase_read_lock+0xc3/0x180 kernel/locking/rwbase_rt.c:114 rwbase_read_lock kernel/locking/rwbase_rt.c:147 [inline] __down_read kernel/locking/rwsem.c:1466 [inline] down_read+0x132/0x200 kernel/locking/rwsem.c:1539 __super_lock fs/super.c:60 [inline] super_lock+0x2d6/0x3d0 fs/super.c:122 __iterate_supers+0x126/0x290 fs/super.c:926 ksys_sync fs/sync.c:102 [inline] __ia32_sys_sync+0xa0/0x120 fs/sync.c:111 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: 0033:0x7feb0e9fc819 RSP: 002b:00007feb0cc56028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007feb0ec75fa0 RCX: 00007feb0e9fc819 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007feb0ec75fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007feb0ec76038 R14: 00007feb0ec75fa0 R15: 00007fffb4afc588 INFO: task syz.3.1837:24947 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.1837 state:D stack:27424 pid:24947 tgid:24888 ppid:21245 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x1553/0x5240 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7289 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760 __rwbase_read_lock+0xc3/0x180 kernel/locking/rwbase_rt.c:114 rwbase_read_lock kernel/locking/rwbase_rt.c:147 [inline] __down_read kernel/locking/rwsem.c:1466 [inline] down_read+0x132/0x200 kernel/locking/rwsem.c:1539 __super_lock fs/super.c:60 [inline] super_lock+0x2d6/0x3d0 fs/super.c:122 __iterate_supers+0x126/0x290 fs/super.c:926 ksys_sync fs/sync.c:102 [inline] __ia32_sys_sync+0xa0/0x120 fs/sync.c:111 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: 0033:0x7feb0e9fc819 RSP: 002b:00007feb0cc35028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007feb0ec76090 RCX: 00007feb0e9fc819 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007feb0ec76090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007feb0ec76128 R14: 00007feb0ec76090 R15: 00007fffb4afc588 INFO: task syz.3.1837:24948 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.1837 state:D stack:29024 pid:24948 tgid:24888 ppid:21245 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x1553/0x5240 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7289 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760 __rwbase_read_lock+0xc3/0x180 kernel/locking/rwbase_rt.c:114 rwbase_read_lock kernel/locking/rwbase_rt.c:147 [inline] __down_read kernel/locking/rwsem.c:1466 [inline] down_read+0x132/0x200 kernel/locking/rwsem.c:1539 __super_lock fs/super.c:60 [inline] super_lock+0x2d6/0x3d0 fs/super.c:122 __iterate_supers+0x126/0x290 fs/super.c:926 ksys_sync fs/sync.c:102 [inline] __ia32_sys_sync+0xa0/0x120 fs/sync.c:111 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: 0033:0x7feb0e9fc819 RSP: 002b:00007feb0cc14028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007feb0ec76180 RCX: 00007feb0e9fc819 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007feb0ec76180 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007feb0ec76218 R14: 00007feb0ec76180 R15: 00007fffb4afc588 Showing all locks held in the system: 1 lock held by khungtaskd/38: #0: ffffffff8ddcb9c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8ddcb9c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8ddcb9c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by kworker/u8:10/4557: #0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc900105d7c40 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc900105d7c40 ((reaper_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 2 locks held by getty/5550: #0: ffff8880373770a0 (&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/u9:2/5794: #0: ffff888058774138 ((wq_completion)hci5){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff888058774138 ((wq_completion)hci5){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc9000464fc40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc9000464fc40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 #2: ffff88805fc7cf80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1d3/0x400 net/bluetooth/hci_sync.c:331 7 locks held by kworker/1:4/5855: 2 locks held by kworker/u8:11/6441: #0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc90006fafc40 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc90006fafc40 (connector_reaper_work){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 3 locks held by syz-executor/8747: 1 lock held by syz.3.1837/24891: #0: ffff88803fae80d0 (&type->s_umount_key#65){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff88803fae80d0 (&type->s_umount_key#65){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 1 lock held by syz.3.1837/24947: #0: ffff88803fae80d0 (&type->s_umount_key#65){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff88803fae80d0 (&type->s_umount_key#65){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 1 lock held by syz.3.1837/24948: #0: ffff88803fae80d0 (&type->s_umount_key#65){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff88803fae80d0 (&type->s_umount_key#65){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 2 locks held by kworker/0:3/27043: 1 lock held by syz.9.1936/27563: #0: ffff88803fae80d0 (&type->s_umount_key#65){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff88803fae80d0 (&type->s_umount_key#65){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 2 locks held by kworker/u8:7/28274: #0: ffff888019c44938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff888019c44938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc9000d7b7c40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc9000d7b7c40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 2 locks held by kworker/u8:15/28278: 5 locks held by syz.1.2043/28829: 2 locks held by syz.7.2037/28834: 3 locks held by syz.2.2042/28854: 1 lock held by syz.5.2047/28874: #0: ffffffff8e4de058 (tomoyo_ss){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:187 [inline] #0: ffffffff8e4de058 (tomoyo_ss){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:294 [inline] #0: ffffffff8e4de058 (tomoyo_ss){.+.+}-{0:0}, at: tomoyo_read_lock security/tomoyo/common.h:1112 [inline] #0: ffffffff8e4de058 (tomoyo_ss){.+.+}-{0:0}, at: tomoyo_mount_permission+0x2b3/0x9d0 security/tomoyo/mount.c:238 1 lock held by modprobe/28883: 1 lock held by cmp/28884: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 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: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:436 ret_from_fork+0x51e/0xb90 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: 5855 Comm: kworker/1:4 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Workqueue: events_power_efficient neigh_periodic_work RIP: 0010:check_wait_context kernel/locking/lockdep.c:4870 [inline] RIP: 0010:__lock_acquire+0x482/0x2cf0 kernel/locking/lockdep.c:5187 Code: 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 d8 0b 00 00 <31> c1 ff cb 49 ff cc f7 c1 00 60 00 00 74 cf eb 17 48 c7 c7 d0 8e RSP: 0018:ffffc90004c9f2f8 EFLAGS: 00000087 RAX: 000000000002000b RBX: 000000000000000b RCX: 000000000002000b RDX: 0000000000000003 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff888060eb0d48 R08: ffffffff81767e65 R09: ffffffff8ddcb9c0 R10: ffffc90004c9f5d8 R11: ffffffff81af9290 R12: 0000000000000009 R13: 0000000000000000 R14: ffff888060eb0000 R15: 0000000000000009 FS: 0000000000000000(0000) GS:ffff888126435000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb5fd18d000 CR3: 00000000697e0000 CR4: 00000000003526f0 Call Trace: lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868 rcu_lock_acquire include/linux/rcupdate.h:312 [inline] rcu_read_lock include/linux/rcupdate.h:850 [inline] class_rcu_constructor include/linux/rcupdate.h:1193 [inline] unwind_next_frame+0xc2/0x23c0 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:4538 [inline] slab_alloc_node mm/slub.c:4866 [inline] kmem_cache_alloc_node_noprof+0x22a/0x6e0 mm/slub.c:4918 __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:3574 neigh_notify net/core/neighbour.c:3596 [inline] neigh_cleanup_and_release+0xc2/0x300 net/core/neighbour.c:119 neigh_periodic_work+0xb74/0xe90 net/core/neighbour.c:1030 process_one_work kernel/workqueue.c:3276 [inline] process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245