INFO: task kworker/u10:5:7280 blocked for more than 143 seconds. Tainted: G U W L XTNJ syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u10:5 state:D stack:26776 pid:7280 tgid:7280 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6960 schedule_timeout+0x257/0x290 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common+0x2fc/0x4e0 kernel/sched/completion.c:121 __flush_workqueue+0x3e2/0x1230 kernel/workqueue.c:4033 rds_tcp_listen_stop+0x104/0x150 net/rds/tcp_listen.c:331 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:199 [inline] ops_undo_list+0x2ee/0xab0 net/core/net_namespace.c:252 cleanup_net+0x41b/0x830 net/core/net_namespace.c:696 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 INFO: task syz.0.299:7394 blocked for more than 144 seconds. Tainted: G U W L XTNJ syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.299 state:D stack:26312 pid:7394 tgid:7393 ppid:5834 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6960 schedule_timeout+0x257/0x290 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common+0x2fc/0x4e0 kernel/sched/completion.c:121 __flush_workqueue+0x3e2/0x1230 kernel/workqueue.c:4033 rds_tcp_listen_stop+0x104/0x150 net/rds/tcp_listen.c:331 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:199 [inline] ops_undo_list+0x2ee/0xab0 net/core/net_namespace.c:252 setup_net+0x1ff/0x3a0 net/core/net_namespace.c:462 copy_net_ns+0x351/0x7c0 net/core/net_namespace.c:581 create_new_namespaces+0x3ea/0xab0 kernel/nsproxy.c:130 unshare_nsproxy_namespaces+0xc0/0x1f0 kernel/nsproxy.c:226 ksys_unshare+0x45b/0xa40 kernel/fork.c:3171 __do_sys_unshare kernel/fork.c:3242 [inline] __se_sys_unshare kernel/fork.c:3240 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:3240 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fdbcef8f7c9 RSP: 002b:00007fdbcfda3038 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 00007fdbcf1e5fa0 RCX: 00007fdbcef8f7c9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000080 RBP: 00007fdbcf013f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fdbcf1e6038 R14: 00007fdbcf1e5fa0 R15: 00007fffbbff1198 INFO: task syz.0.299:7395 blocked for more than 144 seconds. Tainted: G U W L XTNJ syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.299 state:D stack:27608 pid:7395 tgid:7393 ppid:5834 task_flags:0x400640 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6960 schedule_timeout+0x257/0x290 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common+0x2fc/0x4e0 kernel/sched/completion.c:121 wait_for_common kernel/sched/completion.c:132 [inline] wait_for_completion_state+0x1c/0x40 kernel/sched/completion.c:269 coredump_wait fs/coredump.c:534 [inline] vfs_coredump+0x848/0x55e0 fs/coredump.c:1196 get_signal+0x22e1/0x26d0 kernel/signal.c:3019 arch_do_signal_or_restart+0x8f/0x7a0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop+0x8c/0x540 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x4ee/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fdbcef8f7c9 RSP: 002b:00007fdbcfd820e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 00007fdbcf1e6098 RCX: 00007fdbcef8f7c9 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007fdbcf1e609c RBP: 00007fdbcf1e6090 R08: 00007fdbcfda4000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fdbcf1e6128 R14: 00007fffbbff10b0 R15: 00007fffbbff1198 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e3c94a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e3c94a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e3c94a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775 2 locks held by getty/5588: #0: ffff8880320d70a0 (&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/0x1510 drivers/tty/n_tty.c:2211 3 locks held by kworker/u10:5/7280: #0: ffff88801badf148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232 #1: ffffc9000440fc90 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233 #2: ffffffff9012e790 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xad/0x830 net/core/net_namespace.c:670 1 lock held by syz.0.299/7394: #0: ffffffff9012e790 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x333/0x7c0 net/core/net_namespace.c:577 1 lock held by syz.2.509/8446: #0: ffffffff9012e790 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x333/0x7c0 net/core/net_namespace.c:577 1 lock held by syz.1.533/8558: #0: ffffffff9012e790 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x333/0x7c0 net/core/net_namespace.c:577 1 lock held by syz.5.577/8843: #0: ffffffff9012e790 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x333/0x7c0 net/core/net_namespace.c:577 1 lock held by syz.6.706/9549: #0: ffffffff9012e790 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x333/0x7c0 net/core/net_namespace.c:577 1 lock held by syz.4.785/9949: #0: ffffffff9012e790 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x333/0x7c0 net/core/net_namespace.c:577 2 locks held by syz.9.798/10008: #0: ffffffff9012e790 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x333/0x7c0 net/core/net_namespace.c:577 #1: ffffffff90144f68 (rtnl_mutex){+.+.}-{4:4}, at: cfg80211_pernet_exit+0x17/0x120 net/wireless/core.c:1693 1 lock held by syz.7.799/10011: #0: ffffffff90144f68 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff90144f68 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x230 drivers/net/tun.c:3436 3 locks held by syz.8.800/10017: #0: ffffffff9012e790 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x333/0x7c0 net/core/net_namespace.c:577 #1: ffffffff90144f68 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline] #1: ffffffff90144f68 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x7e9/0xab0 net/core/net_namespace.c:248 #2: ffffffff8e3d4bf8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:343 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G U W L XTNJ syzkaller #0 PREEMPT(full) Tainted: [U]=USER, [W]=WARN, [L]=SOFTLOCKUP, [X]=AUX, [T]=RANDSTRUCT, [N]=TEST, [J]=FWCTL Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 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:160 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x133/0x180 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xe66/0x1180 kernel/hung_task.c:515 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246