INFO: task syz-executor.0:4508 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:21440 pid: 4508 ppid: 1 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11bb/0x4390 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537 __mutex_lock_common+0xc71/0x2390 kernel/locking/mutex.c:669 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 fuse_lock_inode+0xcd/0x120 fs/fuse/inode.c:491 fuse_lookup+0xd4/0x5a0 fs/fuse/dir.c:427 __lookup_slow+0x27d/0x3d0 fs/namei.c:1671 lookup_slow+0x53/0x70 fs/namei.c:1688 walk_component+0x319/0x460 fs/namei.c:1984 link_path_walk+0x662/0xd40 fs/namei.c:-1 path_openat+0x27d/0x2f30 fs/namei.c:3746 do_filp_open+0x1b3/0x3e0 fs/namei.c:3777 do_sys_openat2+0x142/0x4a0 fs/open.c:1255 do_sys_open fs/open.c:1271 [inline] __do_sys_openat fs/open.c:1287 [inline] __se_sys_openat fs/open.c:1282 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1282 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f069e7ff581 RSP: 002b:00007ffe3bfa8880 EFLAGS: 00000287 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f069e7ff581 RDX: 0000000000090800 RSI: 00007f069e84a45d RDI: 00000000ffffff9c RBP: 00007ffe3bfa894c R08: 0000000000000000 R09: 0033c083b73a948c R10: 0000000000000000 R11: 0000000000000287 R12: 0000000000000000 R13: 00000000000124c7 R14: 000000000001247c R15: 0000000000000006 INFO: task syz-executor.0:4609 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:25520 pid: 4609 ppid: 4508 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11bb/0x4390 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 request_wait_answer fs/fuse/dev.c:411 [inline] __fuse_request_send fs/fuse/dev.c:430 [inline] fuse_simple_request+0x10e7/0x19c0 fs/fuse/dev.c:515 fuse_lookup_name+0x279/0x700 fs/fuse/dir.c:383 fuse_lookup+0x13b/0x5a0 fs/fuse/dir.c:428 __lookup_slow+0x27d/0x3d0 fs/namei.c:1671 lookup_slow+0x53/0x70 fs/namei.c:1688 walk_component+0x319/0x460 fs/namei.c:1984 link_path_walk+0x662/0xd40 fs/namei.c:-1 path_openat+0x27d/0x2f30 fs/namei.c:3746 do_filp_open+0x1b3/0x3e0 fs/namei.c:3777 do_sys_openat2+0x142/0x4a0 fs/open.c:1255 do_sys_open fs/open.c:1271 [inline] __do_sys_openat fs/open.c:1287 [inline] __se_sys_openat fs/open.c:1282 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1282 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f069e7fe720 RSP: 002b:00007f069db5fe20 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f069e7fe720 RDX: 0000000000000002 RSI: 00007f069db5ff40 RDI: 00000000ffffff9c RBP: 00007f069db5ff40 R08: 0000000000000000 R09: 00000000000004a0 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000004 R13: 00007f069db5ff3c R14: 00007f069db5ff40 R15: 00007f0695740000 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c11c720 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 1 lock held by klogd/3548: #0: ffff8880b903a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475 2 locks held by getty/3954: #0: ffff88814cfdc098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc90002cf62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158 2 locks held by syz-executor.0/4508: #0: ffff88806f768150 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:797 [inline] #0: ffff88806f768150 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: lookup_slow+0x46/0x70 fs/namei.c:1687 #1: ffff88806f7685b8 (&fi->mutex){+.+.}-{3:3}, at: fuse_lock_inode+0xcd/0x120 fs/fuse/inode.c:491 2 locks held by syz-executor.0/4609: #0: ffff88806f768150 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:797 [inline] #0: ffff88806f768150 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: lookup_slow+0x46/0x70 fs/namei.c:1687 #1: ffff88806f7685b8 (&fi->mutex){+.+.}-{3:3}, at: fuse_lock_inode+0xcd/0x120 fs/fuse/inode.c:491 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xe0f/0xe50 kernel/hung_task.c:369 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:tick_irq_enter+0x1/0x460 kernel/time/tick-sched.c:1446 Code: 00 00 fc ff df e9 e6 fe ff ff e8 aa 83 0c 00 49 bc 00 00 00 00 00 fc ff df e9 fd fc ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 55 <48> 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48 81 ec c0 00 00 RSP: 0018:ffffc90000007fd0 EFLAGS: 00000046 RAX: 0000000000010000 RBX: ffffffff8bebc480 RCX: 1ae0bdcc1a35bc00 RDX: 0000000000000000 RSI: ffffffff8a59e7e0 RDI: ffffffff8bebc480 RBP: 00000000817dec01 R08: dffffc0000000000 R09: fffffbfff1ad26b6 R10: fffffbfff1ad26b6 R11: ffffc90000007ff8 R12: 0000000000000000 R13: 0000000000000000 R14: dffffc0000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000564be8bb0660 CR3: 000000001e126000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: irq_enter_rcu+0x9a/0xe0 kernel/softirq.c:622 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:default_idle+0xb/0x10 arch/x86/kernel/process.c:730 Code: bf 48 89 df e8 c6 03 11 f8 eb b5 e8 ef b5 f6 ff 00 00 cc cc 00 00 cc cc 00 00 cc cc 00 00 cc 66 90 0f 00 2d 17 93 5a 00 fb f4 0f 1f 40 00 41 57 41 56 53 49 be 00 00 00 00 00 fc ff df 65 48 RSP: 0018:ffffffff8be07dc8 EFLAGS: 000002c6 RAX: 1ae0bdcc1a35bc00 RBX: ffffffff8bebc480 RCX: 1ae0bdcc1a35bc00 RDX: 0000000000000001 RSI: ffffffff8a0b1be0 RDI: ffffffff8a59e800 RBP: ffffffff8be07ef8 R08: dffffc0000000000 R09: ffffed1017207662 R10: ffffed1017207662 R11: 1ffff11017207661 R12: ffffffff8d6935a8 R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff17d7890 default_idle_call+0x81/0xc0 kernel/sched/idle.c:112 cpuidle_idle_call kernel/sched/idle.c:194 [inline] do_idle+0x21b/0x5b0 kernel/sched/idle.c:306 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:403 start_kernel+0x486/0x530 init/main.c:1154 secondary_startup_64_no_verify+0xb1/0xbb