INFO: task syz.0.1063:9844 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.1063 state:D stack:25400 pid:9844 tgid:9844 ppid:5824 task_flags:0x400040 flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5257 [inline] __schedule+0x14bc/0x5000 kernel/sched/core.c:6864 __schedule_loop kernel/sched/core.c:6946 [inline] schedule+0x165/0x360 kernel/sched/core.c:6961 request_wait_answer fs/fuse/dev.c:585 [inline] __fuse_request_send fs/fuse/dev.c:599 [inline] __fuse_simple_request+0x11d2/0x1bb0 fs/fuse/dev.c:693 fuse_simple_request fs/fuse/fuse_i.h:1263 [inline] fuse_flush+0x5d4/0x800 fs/fuse/file.c:494 filp_flush+0xbd/0x190 fs/open.c:1533 filp_close+0x1d/0x40 fs/open.c:1546 __range_close fs/file.c:790 [inline] __do_sys_close_range fs/file.c:849 [inline] __se_sys_close_range+0x359/0x650 fs/file.c:813 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fea2fb8f749 RSP: 002b:00007fffa9388e18 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: ffffffffffffffda RBX: 0000000000064976 RCX: 00007fea2fb8f749 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007fea2fde7da0 R08: 0000000000000001 R09: 00000014a938910f R10: 0000001b2fa20000 R11: 0000000000000246 R12: 00007fea2fde5fac R13: 00007fea2fde5fa0 R14: ffffffffffffffff R15: 00007fffa9388f30 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e3419e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e3419e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e3419e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5581: #0: ffff88814cde50a0 (&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+0x449/0x1460 drivers/tty/n_tty.c:2211 4 locks held by kworker/0:3/5871: 2 locks held by kworker/u8:1/11284: #0: ffff88813fe69948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3236 #1: ffff8880b8724588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933 2 locks held by syz.8.1414/11331: #0: ffff88802273c420 (sb_writers#20){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:509 #1: ffff88805c1ac048 (&type->i_mutex_dir_key#8){++++}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #1: ffff88805c1ac048 (&type->i_mutex_dir_key#8){++++}-{4:4}, at: vfs_set_acl+0x3cd/0xb00 fs/posix_acl.c:1114 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 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] __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+0xf95/0xfe0 kernel/hung_task.c:515 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 16 Comm: rcu_preempt Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:pool_should_refill lib/debugobjects.c:144 [inline] RIP: 0010:debug_objects_fill_pool lib/debugobjects.c:702 [inline] RIP: 0010:debug_object_assert_init+0x5e/0x380 lib/debugobjects.c:1003 Code: 87 fd 48 c7 44 24 28 05 00 00 00 48 89 5c 24 30 4c 89 74 24 38 80 3d f8 39 22 0b 00 0f 85 ce 01 00 00 66 90 8b 05 8a 3f 09 0a <3b> 05 88 3f 09 0a 0f 82 00 02 00 00 f3 0f 1e fa 49 bf 00 00 00 00 RSP: 0018:ffffc90000157878 EFLAGS: 00000246 RAX: 0000000000000120 RBX: ffffc90000157a40 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffc900001578a0 RBP: ffffc90000157a10 R08: ffffc9000015789f R09: 0000000000000000 R10: ffffc90000157890 R11: fffff5200002af14 R12: ffffc90000157a40 R13: 1ffff9200002af2c R14: ffffffff8b8d2480 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888125a03000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c425dd4 CR3: 000000000e13a000 CR4: 00000000003526f0 Call Trace: debug_timer_assert_init kernel/time/timer.c:803 [inline] debug_assert_init kernel/time/timer.c:848 [inline] __try_to_del_timer_sync+0x29/0x390 kernel/time/timer.c:1457 __timer_delete_sync+0x1fe/0x2d0 kernel/time/timer.c:1621 schedule_timeout+0x133/0x270 kernel/time/sleep_timeout.c:100 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246