INFO: task syz.4.4889:23472 blocked for more than 143 seconds.
Not tainted 6.15.0-rc7-syzkaller-00144-gb1427432d3b6 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.4889 state:D stack:27592 pid:23472 tgid:23471 ppid:5828 task_flags:0x400040 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x168f/0x4c70 kernel/sched/core.c:6767
__schedule_loop kernel/sched/core.c:6845 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6860
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917
rwsem_down_read_slowpath+0x552/0x880 kernel/locking/rwsem.c:1084
__down_read_common kernel/locking/rwsem.c:1248 [inline]
__down_read kernel/locking/rwsem.c:1261 [inline]
down_read+0x98/0x2e0 kernel/locking/rwsem.c:1526
__super_lock fs/super.c:58 [inline]
super_lock+0x2a9/0x3b0 fs/super.c:120
super_lock_shared fs/super.c:139 [inline]
iterate_supers+0x80/0x180 fs/super.c:931
ksys_sync+0x94/0x150 fs/sync.c:102
__ia32_sys_sync+0xe/0x20 fs/sync.c:113
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f52d418e969
RSP: 002b:00007f52d1ff6038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f52d43b5fa0 RCX: 00007f52d418e969
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f52d43b5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f52d43b5fa0 R15: 00007ffc310ec278
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8df3dee0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8df3dee0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8df3dee0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6764
3 locks held by kworker/u8:2/36:
#0: ffff88801a089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff88801a089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319
#1: ffffc90000ad7c60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc90000ad7c60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319
#2: ffffffff8f2e8888 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303
2 locks held by getty/5583:
#0: ffff88814d44d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900036442f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
1 lock held by syz-executor/5820:
#0: ffff88803473a0e0 (&type->s_umount_key#60){++++}-{4:4}, at: __super_lock fs/super.c:56 [inline]
#0: ffff88803473a0e0 (&type->s_umount_key#60){++++}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline]
#0: ffff88803473a0e0 (&type->s_umount_key#60){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505
1 lock held by syz.4.4889/23472:
#0: ffff88803473a0e0 (&type->s_umount_key#60){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88803473a0e0 (&type->s_umount_key#60){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:120
1 lock held by syz.7.5245/24825:
#0: ffff88803473a0e0 (&type->s_umount_key#60){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88803473a0e0 (&type->s_umount_key#60){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:120
2 locks held by syz.6.5270/24924:
#0: ffffffff8f2e8888 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:633 [inline]
#0: ffffffff8f2e8888 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3390
#1: ffffffff8df439b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline]
#1: ffffffff8df439b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f4/0x730 kernel/rcu/tree_exp.h:998
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc7-syzkaller-00144-gb1427432d3b6 #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:274 [inline]
watchdog+0xfee/0x1030 kernel/hung_task.c:437
kthread+0x711/0x8a0 kernel/kthread.c:464
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
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: 0 Comm: swapper/0 Not tainted 6.15.0-rc7-syzkaller-00144-gb1427432d3b6 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:81
Code: 43 d4 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 a3 8f 18 00 f3 0f 1e fa fb f4 18 d4 02 00 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffffff8dc07d80 EFLAGS: 000002c6
RAX: 4b850c27df075200 RBX: ffffffff81977028 RCX: 4b850c27df075200
RDX: 0000000000000001 RSI: ffffffff8d73aa78 RDI: ffffffff8bc12300
RBP: ffffffff8dc07ec0 R08: ffff8880b8832b5b R09: 1ffff1101710656b
R10: dffffc0000000000 R11: ffffed101710656c R12: ffffffff8f7e0b70
R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1b92a48
FS: 0000000000000000(0000) GS:ffff8881260f6000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f13ff580178 CR3: 0000000033b22000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:748
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
rest_init+0x2de/0x300 init/main.c:743
start_kernel+0x470/0x4f0 init/main.c:1099
x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:513
x86_64_start_kernel+0x66/0x70 arch/x86/kernel/head64.c:494
common_startup_64+0x13e/0x147