INFO: task syz.3.5088:26445 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.3.5088 state:D stack:28136 pid:26445 tgid:26443 ppid:18090 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1295/0x67a0 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7283 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7340 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0xced/0x1b10 kernel/locking/mutex.c:820 sync_bdevs+0x153/0x480 block/bdev.c:1296 ksys_sync+0xb0/0xf0 fs/sync.c:105 __do_sys_sync+0xe/0x20 fs/sync.c:111 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc5d3b9ce59 RSP: 002b:00007fc5d49d7028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007fc5d3e16090 RCX: 00007fc5d3b9ce59 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fc5d3e16090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc5d3e16128 R14: 00007fc5d3e16090 R15: 00007ffc4bd52478 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e7e55e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e7e55e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8e7e55e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775 2 locks held by getty/5373: #0: ffff88803a4b00a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14f0 drivers/tty/n_tty.c:2211 5 locks held by kworker/1:4/22274: #0: ffff88801f6c2140 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3289 #1: ffffc900035a7d08 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3290 #2: ffff88802b94d1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #2: ffff88802b94d1d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899 #3: ffff88802caa11d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #3: ffff88802caa11d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1076 #4: ffff88803649a1a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #4: ffff88803649a1a0 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1076 1 lock held by udevd/25601: #0: ffff88802835b350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:953 2 locks held by kworker/u8:13/26171: #0: ffff88813fe94940 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3289 #1: ffffc9000558fd08 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3290 3 locks held by kworker/u8:14/26174: 1 lock held by syz.3.5088/26445: #0: ffff88802835b350 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x153/0x480 block/bdev.c:1296 1 lock held by syz.1.5518/28134: #0: ffffffff90840960 (pfkey_mutex){+.+.}-{4:4}, at: pfkey_insert net/key/af_key.c:120 [inline] #0: ffffffff90840960 (pfkey_mutex){+.+.}-{4:4}, at: pfkey_create+0x222/0x600 net/key/af_key.c:167 2 locks held by syz.2.5520/28124: #0: ffff888043e09bd0 (&net->xfrm.xfrm_cfg_mutex){+.+.}-{4:4}, at: pfkey_sendmsg+0x41a/0x840 net/key/af_key.c:3719 #1: ffffffff90840960 (pfkey_mutex){+.+.}-{4:4}, at: pfkey_register+0xf4/0x950 net/key/af_key.c:1716 1 lock held by modprobe/28141: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x1d7/0x230 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+0x141/0x190 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xcb1/0x1030 kernel/hung_task.c:561 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63 Code: e5 92 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 83 41 22 00 fb f4 fc 43 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffffff8e407e00 EFLAGS: 00000246 RAX: 000000000b59a27d RBX: ffffffff8e4955c0 RCX: ffffffff8b895285 RDX: 0000000000000000 RSI: ffffffff8df0f560 RDI: ffffffff8c1c4480 RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed10170867b5 R10: ffff8880b8433dab R11: 0000000000000000 R12: 0000000000000000 R13: fffffbfff1c92ab8 R14: 0000000000000000 R15: ffffffff90d70d50 FS: 0000000000000000(0000) GS:ffff888124383000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7b5c32b340 CR3: 000000005afcd000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline] default_idle+0x9/0x10 arch/x86/kernel/process.c:767 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x464/0x590 kernel/sched/idle.c:352 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:451 rest_init+0x251/0x260 init/main.c:762 start_kernel+0x484/0x490 init/main.c:1220 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x12b/0x130 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x148