INFO: task kworker/u10:2:8176 blocked for more than 143 seconds. Tainted: G U 6.16.0-rc3-syzkaller-00072-gee88bddf7f2f #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u10:2 state:D stack:27880 pid:8176 tgid:8176 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x116a/0x5de0 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6878 schedule_timeout+0x257/0x290 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common+0x2ff/0x4e0 kernel/sched/completion.c:116 __flush_workqueue+0x3e2/0x1230 kernel/workqueue.c:4002 rds_tcp_listen_stop+0x104/0x150 net/rds/tcp_listen.c:351 rds_tcp_kill_sock net/rds/tcp.c:611 [inline] rds_tcp_exit_net+0xcb/0x810 net/rds/tcp.c:634 ops_exit_list net/core/net_namespace.c:200 [inline] ops_undo_list+0x2eb/0xab0 net/core/net_namespace.c:253 cleanup_net+0x408/0x890 net/core/net_namespace.c:686 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task syz.3.407:8178 blocked for more than 144 seconds. Tainted: G U 6.16.0-rc3-syzkaller-00072-gee88bddf7f2f #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.407 state:D stack:26904 pid:8178 tgid:8177 ppid:5835 task_flags:0x400140 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x116a/0x5de0 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6878 schedule_timeout+0x257/0x290 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common+0x2ff/0x4e0 kernel/sched/completion.c:116 __flush_workqueue+0x3e2/0x1230 kernel/workqueue.c:4002 rds_tcp_listen_stop+0x104/0x150 net/rds/tcp_listen.c:351 rds_tcp_kill_sock net/rds/tcp.c:611 [inline] rds_tcp_exit_net+0xcb/0x810 net/rds/tcp.c:634 ops_exit_list net/core/net_namespace.c:200 [inline] ops_undo_list+0x2eb/0xab0 net/core/net_namespace.c:253 setup_net+0x2e1/0x510 net/core/net_namespace.c:457 copy_net_ns+0x2a6/0x5f0 net/core/net_namespace.c:574 create_new_namespaces+0x3ea/0xa90 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc0/0x1f0 kernel/nsproxy.c:218 ksys_unshare+0x45b/0xa40 kernel/fork.c:3121 __do_sys_unshare kernel/fork.c:3192 [inline] __se_sys_unshare kernel/fork.c:3190 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:3190 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x490 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f623e98e929 RSP: 002b:00007f623f72d038 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 00007f623ebb5fa0 RCX: 00007f623e98e929 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000080 RBP: 00007f623ea10b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f623ebb5fa0 R15: 00007ffc586ac2a8 Showing all locks held in the system: 3 locks held by kworker/0:0/9: #0: ffff88801b880d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc900000e7d10 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffffc90000ae7b00 (&x->wait#11){....}-{2:2}, at: complete_with_flags kernel/sched/completion.c:20 [inline] #2: ffffc90000ae7b00 (&x->wait#11){....}-{2:2}, at: complete+0x1d/0x200 kernel/sched/completion.c:47 1 lock held by khungtaskd/31: #0: ffffffff8e5c47c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e5c47c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e5c47c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6770 3 locks held by kworker/u10:2/8176: #0: ffff88801c6fe148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc900041dfd10 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffffffff90338250 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xad/0x890 net/core/net_namespace.c:662 1 lock held by syz.3.407/8178: #0: ffffffff90338250 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x286/0x5f0 net/core/net_namespace.c:570 1 lock held by syz.1.438/8306: #0: ffffffff90338250 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x286/0x5f0 net/core/net_namespace.c:570 3 locks held by kworker/u10:7/8334: #0: ffff88801b889148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc9000c077d10 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffffffff9034e2a8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0x51/0xc0 net/core/link_watch.c:303 1 lock held by syz.2.479/8602: #0: ffffffff90338250 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x286/0x5f0 net/core/net_namespace.c:570 1 lock held by syz.4.513/8796: #0: ffffffff90338250 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x286/0x5f0 net/core/net_namespace.c:570 2 locks held by syz-executor/8997: #0: ffffffff9034e2a8 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:633 [inline] #0: ffffffff9034e2a8 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x230 drivers/net/tun.c:3396 #1: ffffffff8e5cfdb8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x284/0x3c0 kernel/rcu/tree_exp.h:304 1 lock held by syz.0.567/9096: #0: ffffffff90338250 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x286/0x5f0 net/core/net_namespace.c:570 2 locks held by getty/9485: #0: ffff8880323b30a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 1 lock held by syz.6.663/9596: #0: ffffffff90338250 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x286/0x5f0 net/core/net_namespace.c:570 1 lock held by syz.8.675/9673: #0: ffffffff90338250 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x286/0x5f0 net/core/net_namespace.c:570 1 lock held by syz.5.679/9702: #0: ffffffff90338250 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x286/0x5f0 net/core/net_namespace.c:570 1 lock held by syz.9.691/9793: #0: ffffffff8e5cfdb8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:336 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G U 6.16.0-rc3-syzkaller-00072-gee88bddf7f2f #0 PREEMPT(full) Tainted: [U]=USER Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 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:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline] watchdog+0xf70/0x12c0 kernel/hung_task.c:470 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245