INFO: task syslogd:5175 blocked for more than 144 seconds.
Not tainted 6.14.0-rc7-syzkaller-00074-ga7f2e10ecd8f #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syslogd state:D stack:24240 pid:5175 tgid:5175 ppid:1 task_flags:0x400000 flags:0x00000002
Call Trace:
context_switch kernel/sched/core.c:5378 [inline]
__schedule+0xf43/0x5890 kernel/sched/core.c:6765
__schedule_loop kernel/sched/core.c:6842 [inline]
schedule+0xe7/0x350 kernel/sched/core.c:6857
schedule_timeout+0x244/0x280 kernel/time/sleep_timeout.c:75
___down_common+0x2d7/0x460 kernel/locking/semaphore.c:229
__down_common kernel/locking/semaphore.c:250 [inline]
__down+0x20/0x30 kernel/locking/semaphore.c:258
down+0x74/0xa0 kernel/locking/semaphore.c:64
console_lock+0x5b/0xa0 kernel/printk/printk.c:2833
console_device+0x19/0x180 kernel/printk/printk.c:3482
tty_lookup_driver+0x2fb/0x510 drivers/tty/tty_io.c:1930
tty_open_by_driver drivers/tty/tty_io.c:2047 [inline]
tty_open+0x54e/0xf80 drivers/tty/tty_io.c:2129
chrdev_open+0x237/0x6a0 fs/char_dev.c:414
do_dentry_open+0x735/0x1c40 fs/open.c:956
vfs_open+0x82/0x3f0 fs/open.c:1086
do_open fs/namei.c:3830 [inline]
path_openat+0x1e88/0x2d80 fs/namei.c:3989
do_filp_open+0x20c/0x470 fs/namei.c:4016
do_sys_openat2+0x17a/0x1e0 fs/open.c:1428
do_sys_open fs/open.c:1443 [inline]
__do_sys_openat fs/open.c:1459 [inline]
__se_sys_openat fs/open.c:1454 [inline]
__x64_sys_openat+0x175/0x210 fs/open.c:1454
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f867329b9a4
RSP: 002b:00007fff9cdcd000 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007f867329b9a4
RDX: 0000000000000901 RSI: 00007f867343a3b3 RDI: 00000000ffffff9c
RBP: 00007f867343a3b3 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000901
R13: 0000000000000901 R14: 0000000000000901 R15: 000055ae4a109410
Showing all locks held in the system:
3 locks held by kworker/u8:0/12:
1 lock held by khungtaskd/31:
#0: ffffffff8e1bd140 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
#0: ffffffff8e1bd140 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8e1bd140 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6746
2 locks held by kswapd0/85:
2 locks held by kworker/1:2/117:
3 locks held by kworker/u8:6/1147:
#0: ffff88801b081148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3213
#1: ffffc90003fefd18 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3214
#2: ffffffff8fef85a8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0x51/0xc0 net/core/link_watch.c:285
1 lock held by syslogd/5175:
#0: ffffffff8ee88a28 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2046 [inline]
#0: ffffffff8ee88a28 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x53d/0xf80 drivers/tty/tty_io.c:2129
1 lock held by udevd/5193:
1 lock held by dhcpcd/5486:
2 locks held by getty/5568:
#0: ffff8880326140a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc90002fde2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0xfba/0x1480 drivers/tty/n_tty.c:2211
1 lock held by syz-executor/5805:
2 locks held by syz-executor/5815:
3 locks held by syz-executor/5819:
4 locks held by syz-executor/5827:
4 locks held by kworker/0:3/5861:
2 locks held by syz.4.5904/18103:
4 locks held by kworker/u8:8/18122:
3 locks held by kworker/u8:9/18123:
3 locks held by kworker/u8:10/18124:
2 locks held by syz-executor/18125:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.14.0-rc7-syzkaller-00074-ga7f2e10ecd8f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:236 [inline]
watchdog+0xf62/0x12b0 kernel/hung_task.c:399
kthread+0x3af/0x750 kernel/kthread.c:464
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 5827 Comm: syz-executor Not tainted 6.14.0-rc7-syzkaller-00074-ga7f2e10ecd8f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:unwind_next_frame+0xb43/0x20c0 arch/x86/kernel/unwind_orc.c:591
Code: 00 0f 85 ac 12 00 00 4c 89 e2 4d 89 75 38 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 6c 12 00 00 49 8d 7d 58 <49> c7 45 50 00 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48
RSP: 0018:ffffc90000006ab8 EFLAGS: 00000246
RAX: dffffc0000000000 RBX: 0000000000000002 RCX: ffffffff90f69b68
RDX: 1ffff92000000d6f RSI: 1ffff92000000d6e RDI: ffffc90000006b80
RBP: ffffc90000006b70 R08: ffffc90000006b5c R09: ffffffff90f69b6c
R10: ffffc90000006b28 R11: 0000000000007c2b R12: ffffc90000006b78
R13: ffffc90000006b28 R14: ffffc9000403f4d8 R15: ffffc9000403f4d0
FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9242b77d38 CR3: 0000000060a90000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
arch_stack_walk+0x95/0x100 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x95/0xd0 kernel/stacktrace.c:122
kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576
poison_slab_object mm/kasan/common.c:247 [inline]
__kasan_slab_free+0x51/0x70 mm/kasan/common.c:264
kasan_slab_free include/linux/kasan.h:233 [inline]
slab_free_hook mm/slub.c:2353 [inline]
slab_free mm/slub.c:4609 [inline]
kmem_cache_free+0x2e2/0x4d0 mm/slub.c:4711
__skb_ext_put+0x102/0x2c0 net/core/skbuff.c:7011
skb_ext_put include/linux/skbuff.h:4876 [inline]
skb_ext_put include/linux/skbuff.h:4873 [inline]
skb_release_head_state+0x1c2/0x290 net/core/skbuff.c:1092
skb_release_all net/core/skbuff.c:1098 [inline]
__kfree_skb net/core/skbuff.c:1114 [inline]
sk_skb_reason_drop+0xeb/0x1a0 net/core/skbuff.c:1152
kfree_skb_reason include/linux/skbuff.h:1271 [inline]
kfree_skb include/linux/skbuff.h:1280 [inline]
ip6_mc_input+0x7af/0xfd0 net/ipv6/ip6_input.c:591
dst_input include/net/dst.h:469 [inline]
dst_input include/net/dst.h:467 [inline]
ip6_rcv_finish+0x3a2/0x5b0 net/ipv6/ip6_input.c:79
ip_sabotage_in+0x21b/0x290 net/bridge/br_netfilter_hooks.c:993
nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline]
nf_hook_slow+0xbb/0x200 net/netfilter/core.c:626
nf_hook.constprop.0+0x42e/0x750 include/linux/netfilter.h:269
NF_HOOK include/linux/netfilter.h:312 [inline]
ipv6_rcv+0xa4/0x680 net/ipv6/ip6_input.c:309
__netif_receive_skb_one_core+0x12e/0x1e0 net/core/dev.c:5896
__netif_receive_skb+0x1d/0x160 net/core/dev.c:6009
netif_receive_skb_internal net/core/dev.c:6095 [inline]
netif_receive_skb+0x13f/0x7b0 net/core/dev.c:6154
NF_HOOK include/linux/netfilter.h:314 [inline]
NF_HOOK include/linux/netfilter.h:308 [inline]
br_pass_frame_up+0x346/0x490 net/bridge/br_input.c:70
br_handle_frame_finish+0xecc/0x1c90 net/bridge/br_input.c:226
br_nf_hook_thresh+0x303/0x410 net/bridge/br_netfilter_hooks.c:1170
br_nf_pre_routing_finish_ipv6+0x76a/0xfb0 net/bridge/br_netfilter_ipv6.c:154
NF_HOOK include/linux/netfilter.h:314 [inline]
br_nf_pre_routing_ipv6+0x3ce/0x8c0 net/bridge/br_netfilter_ipv6.c:184
br_nf_pre_routing+0x860/0x15b0 net/bridge/br_netfilter_hooks.c:508
nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline]
nf_hook_bridge_pre net/bridge/br_input.c:282 [inline]
br_handle_frame+0xad7/0x14a0 net/bridge/br_input.c:433
__netif_receive_skb_core.constprop.0+0xa20/0x4330 net/core/dev.c:5790
__netif_receive_skb_one_core+0xb1/0x1e0 net/core/dev.c:5894
__netif_receive_skb+0x1d/0x160 net/core/dev.c:6009
process_backlog+0x443/0x15f0 net/core/dev.c:6357
__napi_poll.constprop.0+0xb7/0x550 net/core/dev.c:7191
napi_poll net/core/dev.c:7260 [inline]
net_rx_action+0xa94/0x1010 net/core/dev.c:7382
handle_softirqs+0x213/0x8f0 kernel/softirq.c:561
do_softirq kernel/softirq.c:462 [inline]
do_softirq+0xb2/0xf0 kernel/softirq.c:449
__local_bh_enable_ip+0x100/0x120 kernel/softirq.c:389
spin_unlock_bh include/linux/spinlock.h:396 [inline]
addrconf_ifdown.isra.0+0x59d/0x1af0 net/ipv6/addrconf.c:3906
addrconf_notify+0x220/0x19c0 net/ipv6/addrconf.c:3775
notifier_call_chain+0xb7/0x410 kernel/notifier.c:85
call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2206
call_netdevice_notifiers_extack net/core/dev.c:2244 [inline]
call_netdevice_notifiers net/core/dev.c:2258 [inline]
dev_close_many+0x333/0x6a0 net/core/dev.c:1748
unregister_netdevice_many_notify+0x48a/0x1f30 net/core/dev.c:11859
unregister_netdevice_many net/core/dev.c:11951 [inline]
unregister_netdevice_queue+0x307/0x3f0 net/core/dev.c:11821
unregister_netdevice include/linux/netdevice.h:3337 [inline]
__tun_detach+0x1241/0x1530 drivers/net/tun.c:685
tun_detach drivers/net/tun.c:701 [inline]
tun_chr_close+0xc2/0x230 drivers/net/tun.c:3517
__fput+0x3ff/0xb70 fs/file_table.c:464
task_work_run+0x14e/0x250 kernel/task_work.c:227
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0xad8/0x2db0 kernel/exit.c:938
do_group_exit+0xd3/0x2a0 kernel/exit.c:1087
get_signal+0x24ed/0x26c0 kernel/signal.c:3036
arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x150/0x2a0 kernel/entry/common.c:218
do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1b6458b97a
Code: Unable to access opcode bytes at 0x7f1b6458b950.
RSP: 002b:00007ffcf6af7ad8 EFLAGS: 00000206 ORIG_RAX: 0000000000000106
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 00007f1b6458b97a
RDX: 00007ffcf6af7ae0 RSI: 00007f1b6464a6c2 RDI: 0000000000000003
RBP: 00007ffcf6af7ae0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000001000 R11: 0000000000000206 R12: 00007ffcf6af8ce0
R13: 00007f1b6460e08c R14: 0000000000050386 R15: 00007ffcf6af8d20