INFO: task syz.8.3994:22066 blocked for more than 144 seconds. Not tainted 6.16.0-rc5-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.8.3994 state:D stack:24976 pid:22066 tgid:22066 ppid:15200 task_flags:0x400040 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5401 [inline] __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6790 __schedule_loop kernel/sched/core.c:6868 [inline] schedule+0x165/0x360 kernel/sched/core.c:6883 request_wait_answer fs/fuse/dev.c:565 [inline] __fuse_request_send fs/fuse/dev.c:579 [inline] __fuse_simple_request+0xf15/0x18d0 fs/fuse/dev.c:673 fuse_simple_request fs/fuse/fuse_i.h:1237 [inline] fuse_flush+0x5d4/0x800 fs/fuse/file.c:475 filp_flush+0xbd/0x190 fs/open.c:1549 filp_close+0x1d/0x40 fs/open.c:1562 __range_close fs/file.c:752 [inline] __do_sys_close_range fs/file.c:811 [inline] __se_sys_close_range+0x359/0x650 fs/file.c:775 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa49fb8e929 RSP: 002b:00007fffd3e813c8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: ffffffffffffffda RBX: 00007fa49fdb7ba0 RCX: 00007fa49fb8e929 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007fa49fdb7ba0 R08: 00000000000166dc R09: 00000019d3e816bf R10: 00007fa49fdb7ac0 R11: 0000000000000246 R12: 00000000001b8f8a R13: 00007fa49fdb6160 R14: ffffffffffffffff R15: 00007fffd3e814e0 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e13ee60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13ee60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e13ee60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770 2 locks held by getty/5596: #0: ffff8880350ba0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000333b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc5-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 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:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline] watchdog+0xfee/0x1030 kernel/hung_task.c:470 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 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: 23312 Comm: syz.4.4304 Not tainted 6.16.0-rc5-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:rcu_lockdep_current_cpu_online+0x60/0x120 kernel/rcu/tree.c:3998 Code: 09 89 c3 83 f8 08 0f 83 c7 00 00 00 49 be 00 00 00 00 00 fc ff df 48 8d 1c dd 60 8c ba 8d 48 89 d8 48 c1 e8 03 42 80 3c 30 00 <74> 08 48 89 df e8 06 17 7a 00 48 8b 03 48 8d 98 00 9e 9e 92 48 8d RSP: 0018:ffffc9000d91f2e8 EFLAGS: 00000246 RAX: 1ffffffff1b7518c RBX: ffffffff8dba8c60 RCX: 8fdd0823a4765900 RDX: 0000000000000000 RSI: ffffffff8be1c1e0 RDI: ffffffff8be1c1a0 RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff822c9727 R10: dffffc0000000000 R11: fffff940001afb91 R12: 0000000000035f72 R13: dffffc0000000000 R14: dffffc0000000000 R15: 0000000000001000 FS: 0000000000000000(0000) GS:ffff888125c51000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c2f70f0 CR3: 00000000275d4000 CR4: 00000000003526f0 Call Trace: rcu_read_lock_held_common kernel/rcu/update.c:113 [inline] rcu_read_lock_held+0x1e/0x50 kernel/rcu/update.c:349 lookup_page_ext mm/page_ext.c:254 [inline] page_ext_lookup+0xe7/0x180 mm/page_ext.c:520 page_ext_iter_begin include/linux/page_ext.h:132 [inline] page_table_check_clear+0x278/0x700 mm/page_table_check.c:78 ptep_get_and_clear_full arch/x86/include/asm/jump_label.h:-1 [inline] get_and_clear_full_ptes include/linux/pgtable.h:714 [inline] zap_present_folio_ptes mm/memory.c:1505 [inline] zap_present_ptes mm/memory.c:1590 [inline] do_zap_pte_range mm/memory.c:1691 [inline] zap_pte_range mm/memory.c:1735 [inline] zap_pmd_range mm/memory.c:1827 [inline] zap_pud_range mm/memory.c:1856 [inline] zap_p4d_range mm/memory.c:1877 [inline] unmap_page_range+0x3249/0x41c0 mm/memory.c:1898 unmap_single_vma mm/memory.c:1941 [inline] unmap_vmas+0x399/0x580 mm/memory.c:1985 exit_mmap+0x248/0xb50 mm/mmap.c:1284 __mmput+0x118/0x410 kernel/fork.c:1121 exit_mm+0x1da/0x2c0 kernel/exit.c:581 do_exit+0x648/0x22e0 kernel/exit.c:952 do_group_exit+0x21c/0x2d0 kernel/exit.c:1105 get_signal+0x125e/0x1310 kernel/signal.c:3034 arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:111 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe85498e929 Code: Unable to access opcode bytes at 0x7fe85498e8ff. RSP: 002b:00007fe8557810e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007fe854bb6088 RCX: 00007fe85498e929 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fe854bb6088 RBP: 00007fe854bb6080 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe854bb608c R13: 0000000000000000 R14: 00007ffee3f88540 R15: 00007ffee3f88628