INFO: task syz-executor.0:6052 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:21576 pid:6052 tgid:6052 ppid:1 task_flags:0x400140 flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5360 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6964 __schedule_loop kernel/sched/core.c:7046 [inline] schedule+0x165/0x360 kernel/sched/core.c:7061 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7118 rwsem_down_read_slowpath+0x5fd/0x8f0 kernel/locking/rwsem.c:1086 __down_read_common kernel/locking/rwsem.c:1261 [inline] __down_read kernel/locking/rwsem.c:1274 [inline] down_read+0x98/0x2e0 kernel/locking/rwsem.c:1539 inode_lock_shared include/linux/fs.h:995 [inline] lookup_slow+0x46/0x70 fs/namei.c:1832 walk_component fs/namei.c:2137 [inline] link_path_walk+0x935/0xea0 fs/namei.c:2505 path_openat+0x28c/0x3830 fs/namei.c:4050 do_filp_open+0x1fa/0x410 fs/namei.c:4081 do_sys_openat2+0x121/0x1c0 fs/open.c:1435 do_sys_open fs/open.c:1450 [inline] __do_sys_openat fs/open.c:1466 [inline] __se_sys_openat fs/open.c:1461 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1461 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff4c1c7c311 RSP: 002b:00007fffd20c8340 EFLAGS: 00000287 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007ff4c1c7c311 RDX: 0000000000090800 RSI: 00007ff4c1cd7b46 RDI: 00000000ffffff9c RBP: 00007fffd20c840c R08: 0000000000000000 R09: 7fffffffffffffff R10: 0000000000000000 R11: 0000000000000287 R12: 0000000000000000 R13: 0000000000017c7a R14: 0000000000017930 R15: 0000000000000009 INFO: task syz-executor.0:6110 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:25512 pid:6110 tgid:6109 ppid:6052 task_flags:0x400140 flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5360 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6964 __schedule_loop kernel/sched/core.c:7046 [inline] schedule+0x165/0x360 kernel/sched/core.c:7061 request_wait_answer fs/fuse/dev.c:567 [inline] __fuse_request_send fs/fuse/dev.c:581 [inline] __fuse_simple_request+0xf15/0x18d0 fs/fuse/dev.c:675 fuse_simple_request fs/fuse/fuse_i.h:1250 [inline] fuse_lookup_name+0x34c/0x860 fs/fuse/dir.c:381 fuse_lookup+0x1e9/0x640 fs/fuse/dir.c:428 __lookup_slow+0x297/0x3d0 fs/namei.c:1816 lookup_slow+0x53/0x70 fs/namei.c:1833 walk_component fs/namei.c:2137 [inline] link_path_walk+0x935/0xea0 fs/namei.c:2505 path_openat+0x28c/0x3830 fs/namei.c:4050 do_filp_open+0x1fa/0x410 fs/namei.c:4081 do_sys_openat2+0x121/0x1c0 fs/open.c:1435 do_sys_open fs/open.c:1450 [inline] __do_sys_openat fs/open.c:1466 [inline] __se_sys_openat fs/open.c:1461 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1461 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff4c1c7b560 RSP: 002b:00007ff4c2952c00 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000004000 RCX: 00007ff4c1c7b560 RDX: 0000000000004000 RSI: 00007ff4c2952ca0 RDI: 00000000ffffff9c RBP: 00007ff4c2952ca0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 000000000000000b R14: 00007ff4c1d9bf80 R15: 00007fffd20c8098 INFO: task syz-executor.0:6113 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:27752 pid:6113 tgid:6109 ppid:6052 task_flags:0x400040 flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5360 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6964 __schedule_loop kernel/sched/core.c:7046 [inline] schedule+0x165/0x360 kernel/sched/core.c:7061 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7118 rwsem_down_write_slowpath+0x872/0xfe0 kernel/locking/rwsem.c:1185 __down_write_common kernel/locking/rwsem.c:1317 [inline] __down_write kernel/locking/rwsem.c:1326 [inline] down_write_nested+0x1b5/0x200 kernel/locking/rwsem.c:1707 inode_lock_nested include/linux/fs.h:1025 [inline] fuse_reverse_inval_entry+0x5d/0x720 fs/fuse/dir.c:1407 fuse_notify fs/fuse/dev.c:-1 [inline] fuse_dev_do_write+0x3270/0x43a0 fs/fuse/dev.c:2186 fuse_dev_write+0x155/0x1e0 fs/fuse/dev.c:2270 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x5c9/0xb30 fs/read_write.c:686 ksys_write+0x145/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff4c1c7c859 RSP: 002b:00007ff4c29320c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007ff4c1d9c050 RCX: 00007ff4c1c7c859 RDX: 000000000000002c RSI: 00000000200000c0 RDI: 0000000000000003 RBP: 00007ff4c1cd8ad0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007ff4c1d9c050 R15: 00007fffd20c8098 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e33d260 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e33d260 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e33d260 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5618: #0: ffff88814d6dd0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 1 lock held by syz-executor.0/6052: #0: ffff8880765d0148 (&type->i_mutex_dir_key#8){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:995 [inline] #0: ffff8880765d0148 (&type->i_mutex_dir_key#8){++++}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1832 2 locks held by syz-executor.0/6110: #0: ffff8880765d0148 (&type->i_mutex_dir_key#8){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:995 [inline] #0: ffff8880765d0148 (&type->i_mutex_dir_key#8){++++}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1832 #1: ffff8880765d05f8 (&fi->mutex){+.+.}-{4:4}, at: fuse_lock_inode+0xd3/0x120 fs/fuse/inode.c:604 2 locks held by syz-executor.0/6113: #0: ffff88802dfd7328 (&fc->killsb){.+.+}-{4:4}, at: fuse_notify_delete fs/fuse/dev.c:1734 [inline] #0: ffff88802dfd7328 (&fc->killsb){.+.+}-{4:4}, at: fuse_notify fs/fuse/dev.c:2096 [inline] #0: ffff88802dfd7328 (&fc->killsb){.+.+}-{4:4}, at: fuse_dev_do_write+0x31e6/0x43a0 fs/fuse/dev.c:2186 #1: ffff8880765d0148 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1025 [inline] #1: ffff8880765d0148 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: fuse_reverse_inval_entry+0x5d/0x720 fs/fuse/dir.c:1407 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline] watchdog+0xf60/0xfa0 kernel/hung_task.c:495 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 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: 12 Comm: kworker/u8:0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline] RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline] RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline] RIP: 0010:rcu_is_watching+0x5a/0xb0 kernel/rcu/tree.c:751 Code: f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 fc 01 7e 00 48 c7 c3 d8 bf c4 92 49 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38 <84> c0 75 34 8b 03 65 ff 0d b9 1c 1d 11 74 11 83 e0 04 c1 e8 02 5b RSP: 0018:ffffc90000117498 EFLAGS: 00000802 RAX: 0000000000000000 RBX: ffff8880b8732fd8 RCX: 917b9889298aa500 RDX: 0000000000000000 RSI: ffffffff8c03aa40 RDI: ffffffff8c03aa00 RBP: ffffc900001175b0 R08: ffffffff8fc39677 R09: 1ffffffff1f872ce R10: dffffc0000000000 R11: fffffbfff1f872cf R12: ffffffff8e446d78 R13: ffffffff8e446cc0 R14: ffffffff8ddcadd8 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff888125ae7000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005629645d3660 CR3: 000000000e138000 CR4: 00000000003526f0 Call Trace: trace_tlb_flush+0x3a/0x140 include/trace/events/tlb.h:38 switch_mm_irqs_off+0x53e/0x7a0 arch/x86/mm/tlb.c:-1 unuse_temporary_mm+0x136/0x220 arch/x86/mm/tlb.c:1035 __text_poke+0x6c8/0xa10 arch/x86/kernel/alternative.c:2569 text_poke arch/x86/kernel/alternative.c:2612 [inline] smp_text_poke_batch_finish+0x90a/0x1130 arch/x86/kernel/alternative.c:2945 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_disable_cpuslocked+0xc5/0x1b0 kernel/jump_label.c:240 static_key_disable+0x1a/0x20 kernel/jump_label.c:248 toggle_allocation_gate+0x1a1/0x240 mm/kfence/core.c:857 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245