INFO: task syz.2.252:7041 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.252 state:D stack:24296 pid:7041 ppid:5762 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
perf_pending_task_sync kernel/events/core.c:5242 [inline]
_free_event+0x174/0xf30 kernel/events/core.c:5248
put_event kernel/events/core.c:5376 [inline]
perf_event_release_kernel+0x836/0x8c0 kernel/events/core.c:5501
perf_release+0x3b/0x40 kernel/events/core.c:5511
__fput+0x234/0x970 fs/file_table.c:384
task_work_run+0x1ce/0x250 kernel/task_work.c:239
exit_task_work include/linux/task_work.h:43 [inline]
do_exit+0x90b/0x23c0 kernel/exit.c:883
do_group_exit+0x21b/0x2d0 kernel/exit.c:1024
get_signal+0x12fc/0x1400 kernel/signal.c:2902
arch_do_signal_or_restart+0x9c/0x7b0 arch/x86/kernel/signal.c:310
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xf6/0x180 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f4661b8f749
RSP: 002b:00007f46629dc0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: 0000000000000001 RBX: 00007f4661de5fa8 RCX: 00007f4661b8f749
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f4661de5fac
RBP: 00007f4661de5fa0 R08: 0000000000745d1e R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4661de6038 R14: 00007ffcf4d42040 R15: 00007ffcf4d42128
Showing all locks held in the system:
1 lock held by khungtaskd/29:
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
2 locks held by getty/5526:
#0: ffff8880312690a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217
4 locks held by kworker/u4:15/7632:
#0: ffff888017873938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888017873938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc90004b8fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc90004b8fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffffffff8dfa8610 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x136/0xb90 net/core/net_namespace.c:606
#3: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: ip_tunnel_delete_nets+0xcc/0x360 net/ipv4/ip_tunnel.c:1152
2 locks held by syz.8.985/9821:
#0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline]
#0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x41/0x1c0 drivers/net/tun.c:3511
#1: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline]
#1: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x448/0x830 kernel/rcu/tree_exp.h:1004
4 locks held by syz.7.988/9829:
#0: ffff88802f526418 (sb_writers#11){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:412
#1: ffff8880782b7910 (&type->i_mutex_dir_key#7/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:839 [inline]
#1: ffff8880782b7910 (&type->i_mutex_dir_key#7/1){+.+.}-{3:3}, at: filename_create+0x1f6/0x460 fs/namei.c:3890
#2: ffffffff8cd59988 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_lock include/linux/cgroup.h:369 [inline]
#2: ffffffff8cd59988 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_kn_lock_live+0xf2/0x230 kernel/cgroup/cgroup.c:1677
#3: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: cgrp_css_online+0x91/0x2f0 net/core/netprio_cgroup.c:157
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
nmi_cpu_backtrace+0x39b/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
watchdog+0xf41/0xf80 kernel/hung_task.c:379
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 5118 Comm: syslogd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:vfs_read+0x4/0x920 fs/read_write.c:451
Code: ff ff 44 89 e9 80 e1 07 80 c1 03 38 c1 0f 8c 6c ff ff ff 4c 89 ef e8 eb 55 f1 ff e9 5f ff ff ff 66 0f 1f 44 00 00 f3 0f 1e fa <55> 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48 81 ec 20 01
RSP: 0018:ffffc90003277e58 EFLAGS: 00000246
RAX: ffffffff81ebcbb8 RBX: ffff88802d9eec80 RCX: 0000000000000000
RDX: 00000000000000ff RSI: 000055b786a9c950 RDI: ffff88802d9eec80
RBP: ffffc90003277f10 R08: ffff88802e096943 R09: 1ffff11005c12d28
R10: dffffc0000000000 R11: ffffed1005c12d29 R12: 000055b786a9c950
R13: 0000000000000000 R14: 0000000000000000 R15: ffff88802d9eed70
FS: 00007fcb89070c80(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055556bc235c8 CR3: 000000002e899000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
ksys_read+0x147/0x250 fs/read_write.c:613
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fcb891c0407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007fff22541b90 EFLAGS: 00000202 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007fcb89070c80 RCX: 00007fcb891c0407
RDX: 00000000000000ff RSI: 000055b786a9c950 RDI: 0000000000000000
RBP: 000055b786a9c910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000055b786a9c9a1
R13: 0000000000000000 R14: 000055b786a9c950 R15: 000055b749fdcd98