INFO: task kworker/u10:3:15141 blocked for more than 143 seconds. Not tainted 6.15.0-syzkaller-10769-g7d4e49a77d99 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u10:3 state:D stack:26968 pid:15141 tgid:15141 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:5392 [inline] __schedule+0x116a/0x5de0 kernel/sched/core.c:6781 __schedule_loop kernel/sched/core.c:6859 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6874 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+0x2ee/0xab0 net/core/net_namespace.c:253 cleanup_net+0x408/0x890 net/core/net_namespace.c:686 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c2/0x780 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 Showing all locks held in the system: 2 locks held by ksoftirqd/1/23: #0: ffff8880b853bd98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:606 #1: ffff88802aa22018 (&pid_list->lock){-.-.}-{2:2}, at: trace_pid_list_is_set+0x4c/0x150 kernel/trace/pid_list.c:141 1 lock held by khungtaskd/31: #0: ffffffff8e3c2c00 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e3c2c00 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e3c2c00 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6770 1 lock held by syz-executor/5817: 3 locks held by syz-executor/5833: 2 locks held by getty/13793: #0: ffff88814c9bf0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900032602f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 3 locks held by kworker/u10:3/15141: #0: ffff88801c2fe148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc9000416fd10 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffffffff90130610 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xad/0x890 net/core/net_namespace.c:662 1 lock held by syz.0.3549/15881: #0: ffffffff90130610 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x286/0x5f0 net/core/net_namespace.c:570 1 lock held by syz.1.3643/16231: 1 lock held by syz.4.3690/16363: #0: ffffffff90130610 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x286/0x5f0 net/core/net_namespace.c:570 no locks held by syz-executor/16401. 1 lock held by syz-executor/16414: #0: ffffffff8e3ce1b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:336 1 lock held by syz.2.3802/16745: #0: ffffffff90130610 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x286/0x5f0 net/core/net_namespace.c:570 3 locks held by syz.6.3868/17017: 2 locks held by syz.6.3952/17276: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-syzkaller-10769-g7d4e49a77d99 #0 PREEMPT(full) 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+0x3c2/0x780 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 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 13648 Comm: syz.1.2840 Not tainted 6.15.0-syzkaller-10769-g7d4e49a77d99 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:__kasan_check_read+0x0/0x20 mm/kasan/shadow.c:30 Code: e9 55 21 5b 09 48 83 c4 60 48 c7 c7 e8 34 a5 8d 5b 5d 41 5c e9 01 03 79 ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 8b 0c 24 89 f6 31 d2 e9 5f f0 ff ff 66 66 2e 0f 1f RSP: 0018:ffffc9000afcf850 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff81983fd3 RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffffffff9087ad50 RBP: 0000000000000286 R08: 0000000000000000 R09: fffffbfff35c21c6 R10: ffffffff9ae10e33 R11: 0000000000000001 R12: dffffc0000000000 R13: 0000000000000150 R14: 0000000000000009 R15: ffffc90012f70000 FS: 0000000000000000(0000) GS:ffff888124a75000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f847dc3b990 CR3: 000000007d866000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: instrument_atomic_read include/linux/instrumented.h:68 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] cpumask_test_cpu include/linux/cpumask.h:654 [inline] cpu_online include/linux/cpumask.h:1210 [inline] trace_irq_enable.constprop.0+0x2f/0x120 include/trace/events/preemptirq.h:40 trace_hardirqs_on+0x26/0x40 kernel/trace/trace_preemptirq.c:73 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline] _raw_spin_unlock_irqrestore+0x52/0x80 kernel/locking/spinlock.c:194 __debug_check_no_obj_freed lib/debugobjects.c:1108 [inline] debug_check_no_obj_freed+0x31f/0x600 lib/debugobjects.c:1129 remove_vm_area+0x1ae/0x3f0 mm/vmalloc.c:3283 vfree+0x90/0xb50 mm/vmalloc.c:3406 kcov_put kernel/kcov.c:439 [inline] kcov_put kernel/kcov.c:435 [inline] kcov_close+0x34/0x60 kernel/kcov.c:535 __fput+0x3ff/0xb70 fs/file_table.c:465 task_work_run+0x150/0x240 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x864/0x2bd0 kernel/exit.c:955 do_group_exit+0xd3/0x2a0 kernel/exit.c:1104 get_signal+0x2673/0x26d0 kernel/signal.c:3034 arch_do_signal_or_restart+0x8f/0x790 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x84/0x110 kernel/entry/common.c:111 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] do_syscall_64+0x3f6/0x490 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1d4d18e969 Code: Unable to access opcode bytes at 0x7f1d4d18e93f. RSP: 002b:00007f1d4e0270e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f1d4d3b5fa8 RCX: 00007f1d4d18e969 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f1d4d3b5fa8 RBP: 00007f1d4d3b5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f1d4d3b5fac R13: 0000000000000000 R14: 00007ffed0ef9080 R15: 00007ffed0ef9168