INFO: task kworker/u10:4:12106 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u10:4 state:D stack:26888 pid:12106 tgid:12106 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0xfee/0x60e0 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7004 schedule_timeout+0x1b2/0x280 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common+0x2e7/0x4c0 kernel/sched/completion.c:121 __flush_workqueue+0x3f7/0x1200 kernel/workqueue.c:4083 rds_tcp_listen_stop+0x104/0x160 net/rds/tcp_listen.c:461 rds_tcp_kill_sock net/rds/tcp.c:605 [inline] rds_tcp_exit_net+0xe0/0x870 net/rds/tcp.c:630 ops_exit_list net/core/net_namespace.c:199 [inline] ops_undo_list+0x2ee/0xab0 net/core/net_namespace.c:252 cleanup_net+0x499/0x920 net/core/net_namespace.c:704 process_one_work+0x9d7/0x1920 kernel/workqueue.c:3275 process_scheduled_works kernel/workqueue.c:3358 [inline] worker_thread+0x5da/0xe40 kernel/workqueue.c:3439 kthread+0x370/0x450 kernel/kthread.c:467 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task syz.0.1386:12196 blocked for more than 145 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.1386 state:D stack:26664 pid:12196 tgid:12186 ppid:5822 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0xfee/0x60e0 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7004 schedule_timeout+0x1b2/0x280 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common+0x2e7/0x4c0 kernel/sched/completion.c:121 __flush_workqueue+0x3f7/0x1200 kernel/workqueue.c:4083 rds_tcp_listen_stop+0x104/0x160 net/rds/tcp_listen.c:461 rds_tcp_kill_sock net/rds/tcp.c:605 [inline] rds_tcp_exit_net+0xe0/0x870 net/rds/tcp.c:630 ops_exit_list net/core/net_namespace.c:199 [inline] ops_undo_list+0x2ee/0xab0 net/core/net_namespace.c:252 setup_net+0x1fa/0x3a0 net/core/net_namespace.c:462 copy_net_ns+0x46f/0x7c0 net/core/net_namespace.c:581 create_new_namespaces+0x3ea/0xac0 kernel/nsproxy.c:130 unshare_nsproxy_namespaces+0xc3/0x1f0 kernel/nsproxy.c:226 ksys_unshare+0x473/0xad0 kernel/fork.c:3174 __do_sys_unshare kernel/fork.c:3245 [inline] __se_sys_unshare kernel/fork.c:3243 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:3243 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa3c139c799 RSP: 002b:00007fa3c21cb028 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 00007fa3c1616180 RCX: 00007fa3c139c799 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000080 RBP: 00007fa3c1432bd9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa3c1616218 R14: 00007fa3c1616180 R15: 00007fffb3731dc8 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e7e9220 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e7e9220 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e7e9220 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775 2 locks held by getty/6680: #0: ffff88803874a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000487b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x1500 drivers/tty/n_tty.c:2211 3 locks held by kworker/u10:4/12106: #0: ffff88801c6ae948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x1287/0x1920 kernel/workqueue.c:3250 #1: ffffc900037d7d08 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x93c/0x1920 kernel/workqueue.c:3251 #2: ffffffff905f9b90 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xb8/0x920 net/core/net_namespace.c:675 1 lock held by syz.0.1386/12196: #0: ffffffff905f9b90 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x451/0x7c0 net/core/net_namespace.c:577 1 lock held by syz.3.1705/13474: #0: ffffffff905f9b90 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x451/0x7c0 net/core/net_namespace.c:577 1 lock held by syz.1.1877/14234: #0: ffffffff905f9b90 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x451/0x7c0 net/core/net_namespace.c:577 1 lock held by syz.4.2012/14846: 4 locks held by syz.4.2041/14979: 4 locks held by syz.4.2041/14983: #0: ffffffff8e920970 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1529 [inline] #0: ffffffff8e920970 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm kernel/fork.c:1582 [inline] #0: ffffffff8e920970 (dup_mmap_sem){.+.+}-{0:0}, at: copy_process+0x73cc/0x7a10 kernel/fork.c:2223 #1: ffff8880351d2800 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:554 [inline] #1: ffff8880351d2800 (&mm->mmap_lock){++++}-{4:4}, at: dup_mmap+0x125/0x2180 mm/mmap.c:1740 #2: ffff8880643c6540 (&mm->mmap_lock/1){+.+.}-{4:4}, at: mmap_write_lock_nested include/linux/mmap_lock.h:544 [inline] #2: ffff8880643c6540 (&mm->mmap_lock/1){+.+.}-{4:4}, at: dup_mmap+0x1c7/0x2180 mm/mmap.c:1747 #3: ffffffff8e7e9220 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #3: ffffffff8e7e9220 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #3: ffffffff8e7e9220 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x2f/0x310 mm/pgtable-generic.c:288 1 lock held by syz.4.2041/14986: 4 locks held by syz.4.2041/14988: 1 lock held by syz.4.2041/14991: 4 locks held by syz.4.2041/14994: 4 locks held by syz.4.2041/14995: 4 locks held by syz.4.2041/14996: 4 locks held by syz.4.2041/14997: 4 locks held by syz.4.2041/15002: 2 locks held by syz.4.2041/15006: 1 lock held by syz.4.2041/15008: 4 locks held by syz.4.2041/15009: 4 locks held by syz.4.2041/15010: 4 locks held by syz.4.2041/15011: 4 locks held by syz.4.2041/15014: 3 locks held by syz.4.2041/15015: 4 locks held by syz.4.2041/15016: 4 locks held by syz.4.2041/15018: 4 locks held by syz.4.2041/15023: 4 locks held by syz.4.2041/15027: 4 locks held by syz.4.2041/15029: 4 locks held by syz.4.2041/15030: 1 lock held by dhcpcd-run-hook/15045: #0: ffff8880b843b2e0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2c/0x140 kernel/sched/core.c:647 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x141/0x190 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xd25/0x1050 kernel/hung_task.c:515 kthread+0x370/0x450 kernel/kthread.c:467 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245