INFO: task syz-executor:7083 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:25752 pid:7083 tgid:7083 ppid:1 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5402 [inline]
__schedule+0x16f9/0x5500 kernel/sched/core.c:7204
__schedule_loop kernel/sched/core.c:7283 [inline]
rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7579
rt_mutex_slowlock_block+0x508/0x680 kernel/locking/rtmutex.c:1666
__rt_mutex_slowlock kernel/locking/rtmutex.c:1743 [inline]
__rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1783 [inline]
rt_mutex_slowlock+0x2dc/0x780 kernel/locking/rtmutex.c:1823
__rt_mutex_lock kernel/locking/rtmutex.c:1838 [inline]
__mutex_lock_common kernel/locking/rtmutex_api.c:560 [inline]
mutex_lock_nested+0x168/0x1d0 kernel/locking/rtmutex_api.c:578
rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3828
netdev_run_todo+0x2fc/0x12b0 net/core/dev.c:11720
ops_exit_rtnl_list net/core/net_namespace.c:189 [inline]
ops_undo_list+0x3d8/0x940 net/core/net_namespace.c:248
setup_net+0x2f0/0x340 net/core/net_namespace.c:462
copy_net_ns+0x50e/0x730 net/core/net_namespace.c:579
create_new_namespaces+0x3e7/0x6a0 kernel/nsproxy.c:132
unshare_nsproxy_namespaces+0x149/0x190 kernel/nsproxy.c:234
ksys_unshare+0x57d/0x9f0 kernel/fork.c:3270
__do_sys_unshare kernel/fork.c:3344 [inline]
__se_sys_unshare kernel/fork.c:3342 [inline]
__x64_sys_unshare+0x38/0x50 kernel/fork.c:3342
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe0ea06e127
RSP: 002b:00007ffeb3fa5f98 EFLAGS: 00000202 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007fe0ea2e5f40 RCX: 00007fe0ea06e127
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000
RBP: 00007fe0ea2e67b8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008
R13: 0000000000000003 R14: 00007ffeb3fa61d8 R15: 0000000000000000
Showing all locks held in the system:
3 locks held by rcuc/1/29:
#0: ffffffff8dfcac60 (rcu_read_lock){....}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163
#1: ffffffff8dfcac60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#1: ffffffff8dfcac60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#1: ffffffff8dfcac60 (rcu_read_lock){....}-{1:3}, at: process_backlog+0x271/0xc60 net/core/dev.c:6667
#2: ffffffff8dfcac60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#2: ffffffff8dfcac60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#2: ffffffff8dfcac60 (rcu_read_lock){....}-{1:3}, at: nf_hook include/linux/netfilter.h:242 [inline]
#2: ffffffff8dfcac60 (rcu_read_lock){....}-{1:3}, at: NF_HOOK+0x9e/0x3c0 include/linux/netfilter.h:316
1 lock held by khungtaskd/39:
#0: ffffffff8dfcac60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8dfcac60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff8dfcac60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6777
3 locks held by kworker/u8:2/44:
#0: ffff88813fe8c138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x897/0x1630 kernel/workqueue.c:3293
#1: ffffc90000b67c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x8be/0x1630 kernel/workqueue.c:3294
#2: ffffffff8f390178 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313
6 locks held by kworker/u8:4/76:
#0: ffff88801b69e138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x897/0x1630 kernel/workqueue.c:3293
#1: ffffc9000157fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x8be/0x1630 kernel/workqueue.c:3294
#2: ffffffff8f380c60 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:673
#3: ffff88805ee87160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1102 [inline]
#3: ffff88805ee87160 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:124 [inline]
#3: ffff88805ee87160 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x129/0x420 net/devlink/core.c:555
#4: ffff88805efaa310 (&devlink->lock_key#4){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:292 [inline]
#4: ffff88805efaa310 (&devlink->lock_key#4){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:125 [inline]
#4: ffff88805efaa310 (&devlink->lock_key#4){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x142/0x420 net/devlink/core.c:555
#5: ffffffff8dfd0e30 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3828
2 locks held by kworker/u8:5/84:
#0: ffff88813fe8c138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x897/0x1630 kernel/workqueue.c:3293
#1: ffffc9000152fc40 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: process_one_work+0x8be/0x1630 kernel/workqueue.c:3294
3 locks held by kworker/u8:10/1465:
#0: ffff888030762138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x897/0x1630 kernel/workqueue.c:3293
#1: ffffc9000656fc40 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work+0x8be/0x1630 kernel/workqueue.c:3294
#2: ffffffff8f390178 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#2: ffffffff8f390178 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4761
2 locks held by getty/5365:
#0: ffff8880356750a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003cbe2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13a0 drivers/tty/n_tty.c:2211
2 locks held by syz-executor/7082:
#0: ffffffff8f380c60 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:575
#1: ffffffff8dfd0e30 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3828
2 locks held by syz-executor/7083:
#0: ffffffff8f380c60 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:575
#1: ffffffff8dfd0e30 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3828
1 lock held by syz-executor/7085:
#0: ffffffff8dfd0e30 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3828
1 lock held by syz-executor/7086:
#0: ffffffff8dfd0e30 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3828
2 locks held by syz-executor/7088:
#0: ffffffff8f380c60 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:575
#1: ffffffff8dfd0e30 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3828
1 lock held by syz-executor/7145:
#0: ffffffff8dfd0e30 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3828
1 lock held by syz-executor/7147:
#0: ffffffff8dfd0e30 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3828
1 lock held by syz-executor/7160:
#0: ffffffff8dfd0e30 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3828
1 lock held by syz-executor/7161:
#0: ffffffff8dfd0e30 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3828
1 lock held by syz-executor/7166:
#0: ffffffff8dfd0e30 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3828
1 lock held by syz-executor/7248:
#0: ffffffff8dfd0e30 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3828
1 lock held by syz-executor/7249:
#0: ffffffff8dfd0e30 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3828
1 lock held by syz-executor/7266:
#0: ffffffff8dfd0e30 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3828
1 lock held by syz-executor/7273:
#0: ffffffff8f390178 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:641 [inline]
#0: ffffffff8f390178 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x41/0x1c0 drivers/net/tun.c:3505
1 lock held by syz-executor/7274:
#0: ffffffff8f390178 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:641 [inline]
#0: ffffffff8f390178 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x41/0x1c0 drivers/net/tun.c:3505
2 locks held by syz-executor/7341:
#0: ffffffff8f380c60 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:575
#1: ffffffff8f390178 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x2d5/0x850 net/ipv4/ip_tunnel.c:1146
2 locks held by syz-executor/7342:
#0: ffffffff8f380c60 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:575
#1: ffffffff8f390178 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x2d5/0x850 net/ipv4/ip_tunnel.c:1146
2 locks held by syz-executor/7358:
#0: ffffffff8f380c60 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:575
#1: ffffffff8f390178 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#1: ffffffff8f390178 (rtnl_mutex){+.+.}-{4:4}, at: register_netdevice_notifier_net+0x1a/0xa0 net/core/dev.c:2103
2 locks held by syz-executor/7359:
#0: ffffffff8f380c60 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:575
#1: ffffffff8f390178 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#1: ffffffff8f390178 (rtnl_mutex){+.+.}-{4:4}, at: register_netdevice_notifier_net+0x1a/0xa0 net/core/dev.c:2103
2 locks held by syz-executor/7360:
#0: ffffffff8f380c60 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:575
#1: ffffffff8f390178 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#1: ffffffff8f390178 (rtnl_mutex){+.+.}-{4:4}, at: register_netdevice_notifier_net+0x1a/0xa0 net/core/dev.c:2103
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 39 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122
nmi_trigger_cpumask_backtrace+0x17a/0x380 lib/nmi_backtrace.c:65
trigger_all_cpu_backtrace include/linux/nmi.h:162 [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:353 [inline]
watchdog+0xfd3/0x1030 kernel/hung_task.c:561
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 29 Comm: rcuc/1 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:__lock_acquire+0x817/0x2d10 kernel/locking/lockdep.c:-1
Code: 29 49 ff c7 49 63 86 f8 0b 00 00 49 83 c5 28 49 39 c7 7c d3 e9 b4 00 00 00 48 c7 c7 90 82 e9 8d 4c 89 fe e8 4b 0b 4b 03 eb c3 <89> e8 25 ff 1f 00 00 c1 ed 03 81 e5 00 60 00 00 09 c5 48 89 d8 48
RSP: 0018:ffffc90000a3e6d0 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 36cf7fa31287fe1c RCX: 0000000000000000
RDX: 0000000000000008 RSI: ffff88801de94aa0 RDI: ffff88801de93e00
RBP: 000000000002000b R08: ffffffff8176c406 R09: ffffffff8dfcac60
R10: ffffc90000a3e9d8 R11: ffffffff81b02a50 R12: ffff88801de94aa0
R13: ffff88801de94aa0 R14: ffff88801de93e00 R15: 0000000000000004
FS: 0000000000000000(0000) GS:ffff888125fcd000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fecf3bbb6b0 CR3: 000000005f3a2000 CR4: 00000000003526f0
Call Trace:
lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5870
rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
rcu_read_lock include/linux/rcupdate.h:838 [inline]
class_rcu_constructor include/linux/rcupdate.h:1181 [inline]
unwind_next_frame+0xc3/0x2550 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
unpoison_slab_object mm/kasan/common.c:340 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4583 [inline]
slab_alloc_node mm/slub.c:4912 [inline]
kmem_cache_alloc_noprof+0x33b/0x680 mm/slub.c:4919
kmem_alloc_batch lib/debugobjects.c:371 [inline]
fill_pool+0x156/0x580 lib/debugobjects.c:420
debug_objects_fill_pool+0xcf/0x110 lib/debugobjects.c:752
debug_object_activate+0x6c/0x3a0 lib/debugobjects.c:841
debug_rcu_head_queue kernel/rcu/rcu.h:236 [inline]
__call_rcu_common kernel/rcu/tree.c:3116 [inline]
call_rcu+0x43/0x890 kernel/rcu/tree.c:3251
refdst_drop include/net/dst.h:286 [inline]
skb_dst_drop include/net/dst.h:298 [inline]
skb_release_head_state+0x71/0x360 net/core/skbuff.c:1163
skb_release_all net/core/skbuff.c:1187 [inline]
__kfree_skb+0x24/0x210 net/core/skbuff.c:1203
nft_synproxy_eval_v4+0x352/0x4e0 net/netfilter/nft_synproxy.c:61
nft_synproxy_do_eval+0x305/0x580 net/netfilter/nft_synproxy.c:142
expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]
nft_do_chain+0x48d/0x1ae0 net/netfilter/nf_tables_core.c:285
nft_do_chain_inet+0x360/0x4b0 net/netfilter/nft_chain_filter.c:162
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_slow+0xc5/0x220 net/netfilter/core.c:619
nf_hook include/linux/netfilter.h:273 [inline]
NF_HOOK+0x21f/0x3c0 include/linux/netfilter.h:316
NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:318
__netif_receive_skb_one_core net/core/dev.c:6204 [inline]
__netif_receive_skb net/core/dev.c:6317 [inline]
process_backlog+0x569/0xc60 net/core/dev.c:6668
__napi_poll+0xab/0x550 net/core/dev.c:7727
napi_poll net/core/dev.c:7790 [inline]
net_rx_action+0x696/0xe00 net/core/dev.c:7947
handle_softirqs+0x1de/0x6d0 kernel/softirq.c:626
__do_softirq kernel/softirq.c:660 [inline]
__local_bh_enable_ip+0x170/0x2b0 kernel/softirq.c:302
local_bh_enable include/linux/bottom_half.h:33 [inline]
rcu_do_batch kernel/rcu/tree.c:2636 [inline]
rcu_core kernel/rcu/tree.c:2869 [inline]
rcu_cpu_kthread+0x9e8/0x1470 kernel/rcu/tree.c:2957
smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245