INFO: task syz.5.201:7297 blocked for more than 143 seconds. Not tainted 6.15.0-rc7-syzkaller-00142-g4856ebd99715 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.201 state:D stack:25272 pid:7297 tgid:7296 ppid:6968 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x168f/0x4c70 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x165/0x360 kernel/sched/core.c:6860 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917 rwsem_down_read_slowpath+0x552/0x880 kernel/locking/rwsem.c:1084 __down_read_common kernel/locking/rwsem.c:1248 [inline] __down_read kernel/locking/rwsem.c:1261 [inline] down_read+0x98/0x2e0 kernel/locking/rwsem.c:1526 __super_lock fs/super.c:58 [inline] super_lock+0x2a9/0x3b0 fs/super.c:120 super_lock_shared fs/super.c:139 [inline] iterate_supers+0x80/0x180 fs/super.c:931 ksys_sync+0x94/0x150 fs/sync.c:102 __ia32_sys_sync+0xe/0x20 fs/sync.c:113 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6eaa98e969 RSP: 002b:00007f6eab876038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f6eaabb5fa0 RCX: 00007f6eaa98e969 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f6eaabb5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f6eaabb5fa0 R15: 00007ffdbebee568 Showing all locks held in the system: 3 locks held by kworker/u8:1/13: 1 lock held by khungtaskd/31: #0: ffffffff8df3dee0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8df3dee0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8df3dee0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6764 2 locks held by kworker/u8:7/4507: #0: ffff88801a089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801a089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319 #1: ffffc9000d997c60 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000d997c60 ((reaper_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319 1 lock held by dhcpcd/5483: #0: ffffffff8f2e8888 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f2e8888 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_deladdr+0x20f/0x330 net/ipv6/addrconf.c:4803 2 locks held by getty/5576: #0: ffff888033da20a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002ffe2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 2 locks held by syz-executor/5831: 5 locks held by kworker/u8:8/6991: #0: ffff88801aef3948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801aef3948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319 #1: ffffc90005107c60 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90005107c60 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319 #2: ffffffff8f2dbd50 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0x145/0xbd0 net/core/net_namespace.c:608 #3: ffffffff8f2e8888 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0xdc/0x890 net/core/dev.c:12516 #4: ffffffff8df439b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline] #4: ffffffff8df439b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f4/0x730 kernel/rcu/tree_exp.h:998 1 lock held by syz-executor/7117: #0: ffff8880452d80e0 (&type->s_umount_key#69){++++}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff8880452d80e0 (&type->s_umount_key#69){++++}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff8880452d80e0 (&type->s_umount_key#69){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505 1 lock held by syz.5.201/7297: #0: ffff8880314ba0e0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880314ba0e0 (&type->s_umount_key#55){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:120 1 lock held by syz-executor/7505: #0: ffffffff8df439b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #0: ffffffff8df439b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b7/0x730 kernel/rcu/tree_exp.h:998 3 locks held by kworker/u8:9/8915: #0: ffff88801a089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801a089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319 #1: ffffc90005117c60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90005117c60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319 #2: ffffffff8f2e8888 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 2 locks held by kworker/u8:10/8916: #0: ffff8880b89399d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:605 #1: ffff8880b8923b08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x39e/0x6d0 kernel/sched/psi.c:987 1 lock held by syz-executor/9239: #0: ffffffff8f2e8888 (rtnl_mutex){+.+.}-{4:4}, at: __tun_chr_ioctl+0x37a/0x1d90 drivers/net/tun.c:3038 2 locks held by syz-executor/9280: #0: ffffffff8f2dbd50 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x317/0x590 net/core/net_namespace.c:514 #1: ffffffff8f2e8888 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x2ab/0x800 net/ipv4/ip_tunnel.c:1160 2 locks held by syz.3.381/9328: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc7-syzkaller-00142-g4856ebd99715 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline] watchdog+0xfee/0x1030 kernel/hung_task.c:437 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 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: 978 Comm: kworker/0:2 Not tainted 6.15.0-rc7-syzkaller-00142-g4856ebd99715 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: rcu_gp process_srcu RIP: 0010:__lock_release kernel/locking/lockdep.c:5512 [inline] RIP: 0010:lock_release+0xc3/0x3e0 kernel/locking/lockdep.c:5887 Code: 02 00 00 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 48 8b 5c 24 20 fa 48 c7 c7 36 df 74 8d e8 c4 52 b1 09 65 ff 05 0d 8c d4 10 44 24 20 01 00 00 00 83 3d 0e ea df 0d 00 0f 84 96 01 00 00 41 RSP: 0018:ffffc90003cbf470 EFLAGS: 00000002 RAX: 0000000000000000 RBX: 0000000000000006 RCX: 8d1a434a3e008a00 RDX: ffffffff90193901 RSI: ffffffff8d74df36 RDI: ffffffff8bc12300 RBP: dffffc0000000000 R08: ffffc90003cbf607 R09: 0000000000000000 R10: ffffc90003cbf5f8 R11: fffff52000797ec1 R12: ffffc90003cbf948 R13: ffffffff8171ca05 R14: ffffffff8df3dee0 R15: ffff88802510da00 FS: 0000000000000000(0000) GS:ffff8881260f6000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff5573b8000 CR3: 0000000032228000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:871 [inline] class_rcu_destructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:47 kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:548 insert_work+0x3d/0x330 kernel/workqueue.c:2183 __queue_work+0xcfc/0xfe0 kernel/workqueue.c:2341 queue_delayed_work_on+0x18b/0x280 kernel/workqueue.c:2561 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xade/0x17a0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245