INFO: task syz-executor990:5845 blocked for more than 143 seconds.
      Not tainted 6.16.0-rc4-syzkaller-00013-g66701750d556 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor990 state:D stack:24968 pid:5845  tgid:5845  ppid:5844   task_flags:0x400140 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5396 [inline]
 __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785
 __schedule_loop kernel/sched/core.c:6863 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6878
 netfs_wait_for_request+0x1f0/0x600 fs/netfs/misc.c:450
 netfs_unbuffered_write_iter_locked+0x52a/0x910 fs/netfs/direct_write.c:110
 netfs_unbuffered_write_iter+0x4c4/0x660 fs/netfs/direct_write.c:193
 do_iter_readv_writev+0x56e/0x7f0 fs/read_write.c:-1
 vfs_writev+0x31a/0x960 fs/read_write.c:1057
 do_writev+0x14d/0x2d0 fs/read_write.c:1103
 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: 0033:0x7fe74035cf39
RSP: 002b:00007fff38fde958 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 0030656c69662f2e RCX: 00007fe74035cf39
RDX: 0000000000000002 RSI: 0000200000000000 RDI: 0000000000000007
RBP: 00002000000002c0 R08: 0000000000000006 R09: 0000000000000006
R10: 0000000000000006 R11: 0000000000000246 R12: 0000200000000400
R13: 00007fe7403a604e R14: 0000000000000001 R15: 0000000000000001
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8e13ee20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e13ee20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8e13ee20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
2 locks held by getty/5580:
 #0: ffff888030fce0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90002fee2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
2 locks held by syz-executor990/5845:
 #0: ffff88807c262428 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3096 [inline]
 #0: ffff88807c262428 (sb_writers#8){.+.+}-{0:0}, at: vfs_writev+0x288/0x960 fs/read_write.c:1055
 #1: ffff888078cb0148 (&sb->s_type->i_mutex_key#14){++++}-{4:4}, at: netfs_start_io_direct+0x1ef/0x230 fs/netfs/locking.c:188

=============================================

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc4-syzkaller-00013-g66701750d556 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 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
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.16.0-rc4-syzkaller-00013-g66701750d556 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:__sanitizer_cov_trace_pc+0x4/0x70 kernel/kcov.c:213
Code: 00 00 00 48 8b 3d a4 e6 f8 0b 48 89 de 5b e9 13 91 56 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa <48> 8b 04 24 65 48 8b 0c 25 08 c0 99 92 65 8b 15 88 72 d9 10 81 e2
RSP: 0018:ffffc90000a08a40 EFLAGS: 00000802
RAX: f3f3f300f1f1f1f1 RBX: ffff8880b8739e00 RCX: 1ffff110170e7545
RDX: 0000000000000100 RSI: ffffffff8db5a5e7 RDI: 0000000000000001
RBP: ffffc90000a08b28 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000141158 R12: ffff8880b8739e00
R13: dffffc0000000000 R14: ffffc90000a08ac0 R15: 1ffff92000141154
FS:  0000000000000000(0000) GS:ffff888125d84000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555fa9a8b660 CR3: 000000000df38000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 sched_clock+0xb/0x60 arch/x86/kernel/tsc.c:285
 sched_clock_cpu+0x74/0x430 kernel/sched/clock.c:394
 update_rq_clock+0x100/0x5b0 kernel/sched/core.c:815
 sched_balance_update_blocked_averages+0x20a/0x1580 kernel/sched/fair.c:9916
 update_nohz_stats kernel/sched/fair.c:12596 [inline]
 _nohz_idle_balance+0x345/0x810 kernel/sched/fair.c:12664
 handle_softirqs+0x283/0x870 kernel/softirq.c:579
 __do_softirq kernel/softirq.c:613 [inline]
 invoke_softirq kernel/softirq.c:453 [inline]
 __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
 instr_sysvec_call_function_single arch/x86/kernel/smp.c:266 [inline]
 sysvec_call_function_single+0xa3/0xc0 arch/x86/kernel/smp.c:266
 </IRQ>
 <TASK>
 asm_sysvec_call_function_single+0x1a/0x20 arch/x86/include/asm/idtentry.h:709
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: c3 dd 02 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 63 45 28 00 f3 0f 1e fa fb f4 <e9> 98 dd 02 00 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000197de0 EFLAGS: 000002c2
RAX: bfac171a76ceaf00 RBX: ffffffff81974c88 RCX: bfac171a76ceaf00
RDX: 0000000000000001 RSI: ffffffff8d96e77b RDI: ffffffff8be1b940
RBP: ffffc90000197f20 R08: ffff8880b8732f5b R09: 1ffff110170e65eb
R10: dffffc0000000000 R11: ffffed10170e65ec R12: ffffffff8f9fdaf0
R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff11003a52b40
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:749
 default_idle_call+0x74/0xb0 kernel/sched/idle.c:117
 cpuidle_idle_call kernel/sched/idle.c:185 [inline]
 do_idle+0x1e8/0x510 kernel/sched/idle.c:325
 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:423
 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:315
 common_startup_64+0x13e/0x147
 </TASK>
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.221 msecs