INFO: task syz-executor:10253 blocked for more than 144 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:22984 pid:10253 tgid:10253 ppid:1 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5504 [inline]
__schedule+0x172b/0x5550 kernel/sched/core.c:7228
__schedule_loop kernel/sched/core.c:7307 [inline]
rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7603
rt_mutex_slowlock_block+0x505/0x670 kernel/locking/rtmutex.c:1669
__rt_mutex_slowlock kernel/locking/rtmutex.c:1746 [inline]
__rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1786 [inline]
rt_mutex_slowlock+0x2dc/0x780 kernel/locking/rtmutex.c:1826
__rt_mutex_lock kernel/locking/rtmutex.c:1841 [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:3857
netdev_run_todo+0x2ff/0x12c0 net/core/dev.c:11721
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:3267
__do_sys_unshare kernel/fork.c:3341 [inline]
__se_sys_unshare kernel/fork.c:3339 [inline]
__x64_sys_unshare+0x38/0x50 kernel/fork.c:3339
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: 0033:0x7fdcc25de127
RSP: 002b:00007fff9d557628 EFLAGS: 00000202 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007fdcc2855f40 RCX: 00007fdcc25de127
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000
RBP: 00007fdcc28567b8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008
R13: 0000000000000003 R14: 00007fff9d557868 R15: 0000000000000000
Showing all locks held in the system:
5 locks held by ksoftirqd/0/15:
#0: ffffffff8e261520 (local_bh){.+.+}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163
#1: ffffffff8e3cb2a0 (rcu_read_lock){....}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163
#2: ffffffff8e3cb2a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#2: ffffffff8e3cb2a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#2: ffffffff8e3cb2a0 (rcu_read_lock){....}-{1:3}, at: process_backlog+0x271/0xc60 net/core/dev.c:6668
#3: ffffffff8e3cb2a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#3: ffffffff8e3cb2a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#3: ffffffff8e3cb2a0 (rcu_read_lock){....}-{1:3}, at: nf_hook include/linux/netfilter.h:242 [inline]
#3: ffffffff8e3cb2a0 (rcu_read_lock){....}-{1:3}, at: NF_HOOK+0x9e/0x3c0 include/linux/netfilter.h:316
#4: ffffffff8e3cb2a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#4: ffffffff8e3cb2a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#4: ffffffff8e3cb2a0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1183 [inline]
#4: ffffffff8e3cb2a0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xa6/0x2550 arch/x86/kernel/unwind_orc.c:495
4 locks held by ktimers/1/30:
#0: ffffffff8e261520 (local_bh){.+.+}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163
#1: ffffffff8e3cb2a0 (rcu_read_lock){....}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163
#2: ffffffff8e3cb2a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#2: ffffffff8e3cb2a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#2: ffffffff8e3cb2a0 (rcu_read_lock){....}-{1:3}, at: process_backlog+0x271/0xc60 net/core/dev.c:6668
#3: ffffffff8e3cb2a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#3: ffffffff8e3cb2a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#3: ffffffff8e3cb2a0 (rcu_read_lock){....}-{1:3}, at: nf_hook include/linux/netfilter.h:242 [inline]
#3: ffffffff8e3cb2a0 (rcu_read_lock){....}-{1:3}, at: NF_HOOK+0x9e/0x3c0 include/linux/netfilter.h:316
1 lock held by khungtaskd/39:
#0: ffffffff8e3cb2a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8e3cb2a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#0: ffffffff8e3cb2a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6777
4 locks held by kworker/u8:10/1421:
#0: ffff88801be9e138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x897/0x1630 kernel/workqueue.c:3301
#1: ffffc900062bfc40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x8be/0x1630 kernel/workqueue.c:3302
#2: ffffffff8f7a1620 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:673
#3: ffffffff8e3d1470 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3857
3 locks held by kworker/u8:12/1476:
#0: ffff888032911138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x897/0x1630 kernel/workqueue.c:3301
#1: ffffc900062ffc40 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work+0x8be/0x1630 kernel/workqueue.c:3302
#2: ffffffff8f7b0bb8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#2: ffffffff8f7b0bb8 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4761
3 locks held by kworker/u8:17/3816:
#0: ffff88801ae94138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x897/0x1630 kernel/workqueue.c:3301
#1: ffffc9000e167c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x8be/0x1630 kernel/workqueue.c:3302
#2: ffffffff8f7b0bb8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313
1 lock held by dhcpcd/5272:
#0: ffffffff8f7b0bb8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8f7b0bb8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newroute+0x12b/0x250 net/ipv4/fib_frontend.c:922
2 locks held by getty/5369:
#0: ffff8880365760a0 (&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+0x465/0x1490 drivers/tty/n_tty.c:2211
2 locks held by kworker/1:4/5620:
#0: ffff88813fe57938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x897/0x1630 kernel/workqueue.c:3301
#1: ffffc90004527c40 ((work_completion)(&(&hwstats->traffic_dw)->work)){+.+.}-{0:0}, at: process_one_work+0x8be/0x1630 kernel/workqueue.c:3302
4 locks held by kworker/u8:24/5819:
#0: ffff88801ae92938 ((wq_completion)kvfree_rcu_reclaim){+.+.}-{0:0}, at: process_one_work+0x897/0x1630 kernel/workqueue.c:3301
#1: ffffc900057bfc40 ((work_completion)(&(&krcp->krw_arr[i].rcu_work)->work)){+.+.}-{0:0}, at: process_one_work+0x8be/0x1630 kernel/workqueue.c:3302
#2: ffffffff8e3cb3c0 (rcu_callback){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#2: ffffffff8e3cb3c0 (rcu_callback){....}-{0:0}, at: kvfree_rcu_bulk+0x6d/0x1b0 mm/slab_common.c:1496
#3: ffffffff8e3cb2a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#3: ffffffff8e3cb2a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#3: ffffffff8e3cb2a0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1183 [inline]
#3: ffffffff8e3cb2a0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xa6/0x2550 arch/x86/kernel/unwind_orc.c:495
3 locks held by kworker/1:6/6488:
#0: ffff88813fe57938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x897/0x1630 kernel/workqueue.c:3301
#1: ffffc90003cf7c40 ((fqdir_free_work).work){+.+.}-{0:0}, at: process_one_work+0x8be/0x1630 kernel/workqueue.c:3302
#2: ffffffff8e3d1470 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3857
2 locks held by syz-executor/10204:
#0: ffffffff8f7a1620 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:575
#1: ffffffff8e3d1470 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3857
2 locks held by syz-executor/10253:
#0: ffffffff8f7a1620 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:575
#1: ffffffff8e3d1470 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3857
2 locks held by syz-executor/10265:
#0: ffffffff8f7a1620 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:575
#1: ffffffff8e3d1470 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3857
1 lock held by syz-executor/10296:
#0: ffffffff8e3d1470 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3857
1 lock held by syz-executor/10316:
#0: ffffffff8e3d1470 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3857
1 lock held by syz-executor/10321:
#0: ffffffff8e3d1470 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3857
1 lock held by syz-executor/10362:
#0: ffffffff8f7b0bb8 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:641 [inline]
#0: ffffffff8f7b0bb8 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x41/0x1c0 drivers/net/tun.c:3506
2 locks held by syz-executor/10410:
#0: ffffffff8f7a1620 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:575
#1: ffffffff8f7b0bb8 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x2d5/0x850 net/ipv4/ip_tunnel.c:1146
2 locks held by syz-executor/10416:
#0: ffffffff8f7a1620 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:575
#1: ffffffff8f7b0bb8 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x2d5/0x850 net/ipv4/ip_tunnel.c:1146
2 locks held by syz-executor/10440:
#0: ffffffff8f7a1620 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:575
#1: ffffffff8f7b0bb8 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline]
#1: ffffffff8f7b0bb8 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x2a4/0x940 net/core/net_namespace.c:248
1 lock held by syz-executor/10485:
#0: ffffffff8f7b0bb8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8f7b0bb8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x404/0x1ad0 net/ipv4/devinet.c:978
1 lock held by syz-executor/10493:
#0: ffffffff8f7b0bb8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8f7b0bb8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x404/0x1ad0 net/ipv4/devinet.c:978
1 lock held by syz-executor/10501:
#0: ffffffff8f7b0bb8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8f7b0bb8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x404/0x1ad0 net/ipv4/devinet.c:978
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 39 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
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: 30 Comm: ktimers/1 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:debug_lockdep_rcu_enabled+0x29/0x40 kernel/rcu/update.c:321
Code: 90 f3 0f 1e fa 31 c0 83 3d 43 3f 91 04 00 74 1d 83 3d 5a 51 91 04 00 74 14 65 48 8b 0d 18 55 7d 07 31 c0 83 b9 04 0c 00 00 00 <0f> 94 c0 c3 cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc
RSP: 0018:ffffc90000a4ebb0 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffffff905ead01 RCX: ffff88801e2f1f00
RDX: ffffc90000a4ed01 RSI: dffffc0000000000 RDI: ffffc90000a4ecf0
RBP: dffffc0000000000 R08: ffffc90000a4ecd8 R09: 0000000000000000
R10: ffffc90000a4ed38 R11: fffff52000149da9 R12: ffffc90000a4ece8
R13: ffffc90000a48000 R14: ffffc90000a4ece8 R15: ffffffff81774806
FS: 0000000000000000(0000) GS:ffff888125b6b000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe915d5b6b0 CR3: 00000000308ac000 CR4: 00000000003526f0
Call Trace:
rcu_read_unlock include/linux/rcupdate.h:869 [inline]
class_rcu_destructor include/linux/rcupdate.h:1183 [inline]
unwind_next_frame+0x1b6d/0x2550 arch/x86/kernel/unwind_orc.c:709
__unwind_start+0x5b8/0x760 arch/x86/kernel/unwind_orc.c:787
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0xe3/0x150 arch/x86/kernel/stacktrace.c:24
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
kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2699 [inline]
slab_free mm/slub.c:6400 [inline]
kfree+0x1c5/0x6c0 mm/slub.c:6715
skb_kfree_head net/core/skbuff.c:1077 [inline]
skb_free_head net/core/skbuff.c:1089 [inline]
skb_release_data+0x828/0xa60 net/core/skbuff.c:1116
skb_release_all net/core/skbuff.c:1191 [inline]
__kfree_skb+0x5d/0x210 net/core/skbuff.c:1205
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:6205 [inline]
__netif_receive_skb net/core/dev.c:6318 [inline]
process_backlog+0x569/0xc60 net/core/dev.c:6669
__napi_poll+0xab/0x550 net/core/dev.c:7728
napi_poll net/core/dev.c:7791 [inline]
net_rx_action+0x696/0xe00 net/core/dev.c:7948
handle_softirqs+0x1de/0x6d0 kernel/softirq.c:626
__do_softirq kernel/softirq.c:660 [inline]
run_ktimerd+0x69/0x100 kernel/softirq.c:1155
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