INFO: task syz.0.3845:15037 blocked for more than 143 seconds.
Not tainted syzkaller #0
Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.3845 state:D stack:22056 pid:15037 tgid:15036 ppid:12541 task_flags:0x40054c flags:0x00080001
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x16dc/0x5500 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7607
rt_mutex_slowlock_block+0x55c/0x680 kernel/locking/rtmutex.c:1670
__rt_mutex_slowlock kernel/locking/rtmutex.c:1747 [inline]
__rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1787 [inline]
rt_mutex_slowlock+0x2d4/0x780 kernel/locking/rtmutex.c:1827
__rt_mutex_lock kernel/locking/rtmutex.c:1842 [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/0x530 kernel/rcu/tree.c:3857
netdev_run_todo+0x2ff/0x10d0 net/core/dev.c:11711
tun_detach drivers/net/tun.c:647 [inline]
tun_chr_close+0x13f/0x1c0 drivers/net/tun.c:3506
__fput+0x42a/0xa80 fs/file_table.c:512
task_work_run+0x1d9/0x270 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x73a/0x2360 kernel/exit.c:1004
do_group_exit+0x22d/0x2f0 kernel/exit.c:1147
get_signal+0x121b/0x12c0 kernel/signal.c:3038
arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
exit_to_user_mode_loop+0x104/0x730 kernel/entry/common.c:101
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6e6063de59
RSP: 002b:00007f6e5e896028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: 000000000000003c RBX: 00007f6e608c5fa0 RCX: 00007f6e6063de59
RDX: 0000000000000000 RSI: 0000200000000080 RDI: 0000000000000005
RBP: 00007f6e606d3e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6e608c6038 R14: 00007f6e608c5fa0 R15: 00007ffd0b342be8
Showing all locks held in the system:
3 locks held by pr/legacy/17:
4 locks held by rcuc/0/20:
2 locks held by rcuc/1/28:
1 lock held by khungtaskd/38:
#0: ffffffff8e1c2fc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8e1c2fc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#0: ffffffff8e1c2fc0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:13/2278:
#0: ffff88813ff5c138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#0: ffff88813ff5c138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
#1: ffffc9000749fc40 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#1: ffffc9000749fc40 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
#2: ffffffff8e1c9170 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3857
2 locks held by getty/5356:
#0: ffff88803648d0a0 (&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+0x460/0x1360 drivers/tty/n_tty.c:2211
1 lock held by syz-executor/5606:
3 locks held by kworker/u8:31/7901:
#0: ffff888032c26138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#0: ffff888032c26138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
#1: ffffc900062afc40 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#1: ffffc900062afc40 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
#2: ffffffff8f5b0338 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#2: ffffffff8f5b0338 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4769
4 locks held by kworker/u8:47/7917:
#0: ffff88801aea0938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#0: ffff88801aea0938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
#1: ffffc9000608fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#1: ffffc9000608fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
#2: ffffffff8f5a17a0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf5/0x810 net/core/net_namespace.c:673
#3: ffffffff8e1c9170 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3857
3 locks held by kworker/u8:52/11166:
#0: ffff88813ff5c138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#0: ffff88813ff5c138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
#1: ffffc9001d63fc40 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#1: ffffc9001d63fc40 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
#2: ffffffff8e1c9170 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3857
7 locks held by kworker/u8:53/11167:
2 locks held by kworker/u8:69/11183:
#0: ffff88801ef50138 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#0: ffff88801ef50138 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
#1: ffffc9001d5dfc40 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#1: ffffc9001d5dfc40 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
1 lock held by syz-executor/14413:
#0: ffffffff8e1c9170 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3857
1 lock held by syz.0.3845/15037:
#0: ffffffff8e1c9170 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3857
1 lock held by syz-executor/15105:
#0: ffffffff8e1c9170 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3857
1 lock held by syz-executor/15125:
#0: ffffffff8e1c9170 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3857
1 lock held by syz-executor/15139:
#0: ffffffff8e1c9170 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3857
1 lock held by syz-executor/15166:
#0: ffffffff8e1c9170 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3857
1 lock held by syz-executor/15333:
#0: ffffffff8e1c9170 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3857
1 lock held by syz-executor/15336:
#0: ffffffff8e1c9170 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3857
1 lock held by syz-executor/15354:
#0: ffffffff8e1c9170 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3857
1 lock held by syz-executor/15386:
#0: ffffffff8e1c9170 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3857
1 lock held by syz-executor/15565:
#0: ffffffff8f5b0338 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff8f5b0338 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#0: ffffffff8f5b0338 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a3/0x1bd0 net/core/rtnetlink.c:4158
2 locks held by syz-executor/15567:
#0: ffffffff8faf8738 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8faf8738 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#0: ffffffff8faf8738 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570
#1: ffffffff8f5b0338 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#1: ffffffff8f5b0338 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#1: ffffffff8f5b0338 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a3/0x1bd0 net/core/rtnetlink.c:4158
2 locks held by syz-executor/15586:
1 lock held by syz-executor/15612:
#0: ffffffff8f5b0338 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8f5b0338 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_newaddr+0x65e/0xdf0 net/ipv6/addrconf.c:5062
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
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+0xfd7/0x1030 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 20 Comm: rcuc/0 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:should_failslab+0x4/0x100 mm/failslab.c:20
Code: fd ff ff 48 89 df e8 6b 65 ff ff e9 f5 fc ff ff cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 40 d6 <41> 57 41 56 41 54 53 89 f3 49 89 fe 49 bc 00 00 00 00 00 fc ff df
RSP: 0000:ffffc90000196c50 EFLAGS: 00000246
RAX: 0000000004208040 RBX: 0000000000000820 RCX: dffffc0000000000
RDX: 0000000000000100 RSI: 0000000000000820 RDI: ffff88801e6c8dc0
RBP: 0000000000000820 R08: 0000000000000000 R09: 0000000000000100
R10: dffffc0000000000 R11: ffffed1011335f61 R12: ffff88801cae8000
R13: 1ffff1100e55a45f R14: ffff88801e6c8dc0 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff888125c4e000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f862f4a4232 CR3: 000000003c1c4000 CR4: 00000000003526f0
Call Trace:
slab_pre_alloc_hook mm/slub.c:4567 [inline]
slab_alloc_node mm/slub.c:4925 [inline]
kmem_cache_alloc_noprof+0xa4/0x650 mm/slub.c:4959
skb_ext_maybe_cow net/core/skbuff.c:7112 [inline]
skb_ext_add+0x1b6/0x8e0 net/core/skbuff.c:7187
nf_bridge_unshare net/bridge/br_netfilter_hooks.c:170 [inline]
br_nf_forward_ip+0xc3/0xa30 net/bridge/br_netfilter_hooks.c:686
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+0x23e/0x3f0 include/linux/netfilter.h:316
__br_forward+0x397/0x540 net/bridge/br_forward.c:115
deliver_clone net/bridge/br_forward.c:131 [inline]
maybe_deliver net/bridge/br_forward.c:191 [inline]
br_flood+0x3e6/0x8d0 net/bridge/br_forward.c:245
br_handle_frame_finish+0x1175/0x1990 net/bridge/br_input.c:229
br_nf_hook_thresh+0x3dd/0x4c0 net/bridge/br_netfilter_hooks.c:-1
br_nf_pre_routing_finish_ipv6+0x90c/0xc40 net/bridge/br_netfilter_ipv6.c:-1
NF_HOOK include/linux/netfilter.h:318 [inline]
br_nf_pre_routing_ipv6+0x382/0x6f0 net/bridge/br_netfilter_ipv6.c:183
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_bridge_pre net/bridge/br_input.c:291 [inline]
br_handle_frame+0x1282/0x1520 net/bridge/br_input.c:442
__netif_receive_skb_core+0x989/0x30b0 net/core/dev.c:6093
__netif_receive_skb_one_core net/core/dev.c:6204 [inline]
__netif_receive_skb net/core/dev.c:6319 [inline]
process_backlog+0x351/0xc50 net/core/dev.c:6670
__napi_poll+0xae/0x550 net/core/dev.c:7729
napi_poll net/core/dev.c:7792 [inline]
net_rx_action+0x621/0xd70 net/core/dev.c:7949
handle_softirqs+0x1d9/0x6c0 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
__local_bh_enable_ip+0x170/0x2b0 kernel/softirq.c:302
local_bh_enable include/linux/bottom_half.h:33 [inline]
rcu_cpu_kthread+0xf96/0x1480 kernel/rcu/tree.c:2986
smpboot_thread_fn+0x57c/0xa80 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