INFO: task syz.2.10543:28643 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.2.10543 state:D stack:24832 pid:28643 tgid:28643 ppid:5791 task_flags:0x400040 flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x1553/0x5240 kernel/sched/core.c:6908 __schedule_loop kernel/sched/core.c:6990 [inline] schedule+0x164/0x360 kernel/sched/core.c:7005 request_wait_answer fs/fuse/dev.c:585 [inline] __fuse_request_send fs/fuse/dev.c:599 [inline] __fuse_simple_request+0x121f/0x1c60 fs/fuse/dev.c:693 fuse_simple_request fs/fuse/fuse_i.h:1263 [inline] fuse_flush+0x673/0x8b0 fs/fuse/file.c:494 filp_flush+0xc0/0x190 fs/open.c:1469 filp_close+0x1d/0x40 fs/open.c:1482 __range_close fs/file.c:794 [inline] __do_sys_close_range fs/file.c:855 [inline] __se_sys_close_range+0x3d7/0x900 fs/file.c:819 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: 0033:0x7f6d3996c799 RSP: 002b:00007ffc237bcc78 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: ffffffffffffffda RBX: 00007f6d39be7da0 RCX: 00007f6d3996c799 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f6d39be7da0 R08: 0000000000000006 R09: 0000000000000000 R10: 00007f6d39be7cb0 R11: 0000000000000246 R12: 0000000000091fb0 R13: 00007f6d39be5fac R14: 0000000000091d16 R15: 00007ffc237bcd80 Showing all locks held in the system: 1 lock held by khungtaskd/38: #0: ffffffff8ddcb840 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8ddcb840 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8ddcb840 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5550: #0: ffff888037dc00a0 (&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 7 locks held by syz-executor/11434: 1 lock held by syz.7.12329/32748: 5 locks held by syz.0.12333/32757: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 38 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: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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 32757 Comm: syz.0.12333 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 RIP: 0010:check_preemption_disabled+0x1/0xe0 lib/smp_processor_id.c:13 Code: a0 5d a6 8b 48 c7 c6 e0 5d a6 8b eb 1c 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 <41> 57 41 56 53 65 8b 05 47 93 2b 07 65 8b 0d 3c 93 2b 07 f7 c1 ff RSP: 0018:ffffc900150ef570 EFLAGS: 00000083 RDX: 0000000000000000 RSI: ffffffff8ba65de0 RDI: ffffffff8ba65da0 RBP: ffffc900150ef6a0 R08: ffffffff8f6a30b7 R09: 1ffffffff1ed4616 R10: dffffc0000000000 R11: fffffbfff1ed4617 R12: 1ffff92002a1dec5 R13: dffffc0000000000 R14: ffff88807bdc1740 R15: ffffc900150ef620 FS: 00007fb3a67d56c0(0000) GS:ffff88812633f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f661ad17dac CR3: 0000000075cca000 CR4: 00000000003526f0 Call Trace: rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline] rcu_is_watching+0x15/0xb0 kernel/rcu/tree.c:752 trace_irq_disable+0x3b/0x150 include/trace/events/preemptirq.h:36 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:130 [inline] _raw_spin_lock_irqsave+0x1a/0x60 kernel/locking/spinlock.c:162 rtlock_slowlock kernel/locking/rtmutex.c:1894 [inline] rtlock_lock kernel/locking/spinlock_rt.c:43 [inline] __rt_spin_lock kernel/locking/spinlock_rt.c:49 [inline] rt_spin_lock+0x157/0x400 kernel/locking/spinlock_rt.c:57 spin_lock include/linux/spinlock_rt.h:45 [inline] __skb_try_recv_datagram+0x89/0x1b0 net/core/datagram.c:264 __unix_dgram_recvmsg+0x2e3/0xd50 net/unix/af_unix.c:2571 sock_recvmsg_nosec+0x10c/0x140 net/socket.c:1078 ____sys_recvmsg+0x3ef/0x4b0 net/socket.c:2810 ___sys_recvmsg+0x215/0x590 net/socket.c:2854 do_recvmmsg+0x33a/0x800 net/socket.c:2949 __sys_recvmmsg net/socket.c:3023 [inline] __do_sys_recvmmsg net/socket.c:3046 [inline] __se_sys_recvmmsg net/socket.c:3039 [inline] __x64_sys_recvmmsg+0x198/0x250 net/socket.c:3039 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: 0033:0x7fb3a859c799 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fb3a67d5028 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007fb3a8816090 RCX: 00007fb3a859c799 RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000003 RBP: 00007fb3a8632bd9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fb3a8816128 R14: 00007fb3a8816090 R15: 00007ffc61550bd8