INFO: task syz.5.4770:16745 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.4770 state:D stack:27176 pid:16745 tgid:16742 ppid:16257 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x14fb/0x52c0 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7285 rt_mutex_slowlock_block+0x508/0x680 kernel/locking/rtmutex.c:1647 __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1760 [inline] rt_mutex_slowlock+0x2dc/0x7b0 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] __mutex_lock_common kernel/locking/rtmutex_api.c:534 [inline] mutex_lock_nested+0x168/0x1d0 kernel/locking/rtmutex_api.c:552 sync_bdevs+0x27e/0x470 block/bdev.c:1304 ksys_sync fs/sync.c:105 [inline] __ia32_sys_sync+0xc5/0x120 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: 0033:0x7fdae1f9c629 RSP: 002b:00007fdae01f6028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007fdae2215fa0 RCX: 00007fdae1f9c629 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fdae2215fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fdae2216038 R14: 00007fdae2215fa0 R15: 00007ffc5812cd78 Showing all locks held in the system: 1 lock held by khungtaskd/39: #0: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 4 locks held by kworker/1:2/808: #0: ffff888019c03d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline] #0: ffff888019c03d38 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358 #1: ffffc90004ad7c40 ((rfkill_op_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #1: ffffc90004ad7c40 ((rfkill_op_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358 #2: ffffffff8f471b18 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_epo+0x4c/0x180 net/rfkill/core.c:462 #3: ffff88809354cf80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_poweroff+0x24/0xc0 net/bluetooth/hci_core.c:894 3 locks held by kworker/u8:10/1957: 2 locks held by getty/5556: #0: ffff8880374460a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e7e2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211 1 lock held by syz-executor/5798: #0: ffffffff8f471b18 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_unregister+0xd1/0x230 net/rfkill/core.c:1145 3 locks held by kworker/1:6/5977: #0: ffff888019c03d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline] #0: ffff888019c03d38 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358 #1: ffffc90005187c40 ((work_completion)(&rfkill_global_led_trigger_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #1: ffffc90005187c40 ((work_completion)(&rfkill_global_led_trigger_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358 #2: ffffffff8f471b18 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_global_led_trigger_worker+0x27/0xd0 net/rfkill/core.c:182 1 lock held by udevd/6750: #0: ffff8880264aa4c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xcc0 block/bdev.c:961 1 lock held by syz.5.4770/16745: #0: ffff8880264aa4c8 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x27e/0x470 block/bdev.c:1304 4 locks held by syz.9.6246/20388: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 39 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 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:467 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: 1957 Comm: kworker/u8:10 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: krds_cp_wq#11/0 rds_connect_worker RIP: 0010:trace_lock_release include/trace/events/lock.h:69 [inline] RIP: 0010:lock_release+0x44/0x3d0 kernel/locking/lockdep.c:5879 Code: 8b 05 40 87 ad 10 48 89 44 24 28 0f 1f 44 00 00 65 8b 05 43 87 ad 10 83 f8 08 0f 83 56 02 00 00 89 c0 48 0f a3 05 ac dc c9 0d <73> 0d e8 45 12 09 00 84 c0 0f 84 94 02 00 00 83 3d c6 ef c9 0d 00 RSP: 0018:ffffc90006c1f6c0 EFLAGS: 00000097 RAX: 0000000000000001 RBX: 0000000000000297 RCX: dffffc0000000000 RDX: 0000000000000001 RSI: ffffffff8b242862 RDI: ffff8880b8940570 RBP: 0000000000000001 R08: ffff8880b89405af R09: 1ffff110171280b5 R10: dffffc0000000000 R11: ffffed10171280b6 R12: dffffc0000000000 R13: ffffffff8b242862 R14: ffff8880b8940570 R15: ffff88802ad35ac0 FS: 0000000000000000(0000) GS:ffff888126443000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b3330eff8 CR3: 000000003b760000 CR4: 00000000003526f0 Call Trace: __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:176 [inline] _raw_spin_unlock_irqrestore+0x1b/0x80 kernel/locking/spinlock.c:194 rt_mutex_slowtrylock kernel/locking/rtmutex.c:1395 [inline] __rt_spin_trylock kernel/locking/spinlock_rt.c:106 [inline] rt_spin_trylock+0xd2/0x2b0 kernel/locking/spinlock_rt.c:118 alloc_from_pcs mm/slub.c:4675 [inline] slab_alloc_node mm/slub.c:4815 [inline] __kmalloc_cache_noprof+0x1a0/0x690 mm/slub.c:5334 kmalloc_noprof include/linux/slab.h:962 [inline] slab_free_hook mm/slub.c:2639 [inline] slab_free mm/slub.c:6124 [inline] kmem_cache_free+0x159/0x6b0 mm/slub.c:6254 sk_prot_free net/core/sock.c:2282 [inline] __sk_destruct+0x617/0x880 net/core/sock.c:2384 inet_release+0x143/0x190 net/ipv4/af_inet.c:437 __sock_release net/socket.c:662 [inline] sock_release net/socket.c:690 [inline] __sock_create+0x7a2/0x9d0 net/socket.c:1641 rds_tcp_conn_path_connect+0x2d7/0x930 net/rds/tcp_connect.c:-1 rds_connect_worker+0x1d8/0x290 net/rds/threads.c:176 process_one_work kernel/workqueue.c:3275 [inline] process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245