INFO: task syz-executor:4107 blocked for more than 143 seconds. Not tainted 6.1.112-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21080 pid:4107 ppid:1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5241 [inline] __schedule+0x143f/0x4570 kernel/sched/core.c:6558 schedule+0xbf/0x180 kernel/sched/core.c:6634 schedule_timeout+0xac/0x300 kernel/time/timer.c:1941 do_wait_for_common kernel/sched/completion.c:85 [inline] __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x350/0x610 kernel/sched/completion.c:138 kthread_stop+0x1ab/0x690 kernel/kthread.c:709 ext4_stop_mmpd+0x43/0xb0 fs/ext4/mmp.c:261 ext4_put_super+0xb49/0x10e0 fs/ext4/super.c:1293 generic_shutdown_super+0x130/0x340 fs/super.c:501 kill_block_super+0x7a/0xe0 fs/super.c:1470 deactivate_locked_super+0xa0/0x110 fs/super.c:332 cleanup_mnt+0x490/0x520 fs/namespace.c:1186 task_work_run+0x246/0x300 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xde/0x100 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fcf22d7f327 RSP: 002b:00007fffab812738 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007fcf22df0134 RCX: 00007fcf22d7f327 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fffab8127f0 RBP: 00007fffab8127f0 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fffab813870 R13: 00007fcf22df0134 R14: 00000000000349f3 R15: 00007fffab8138b0 INFO: task kmmpd-loop4:4494 blocked for more than 143 seconds. Not tainted 6.1.112-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kmmpd-loop4 state:D stack:28376 pid:4494 ppid:2 flags:0x00024000 Call Trace: context_switch kernel/sched/core.c:5241 [inline] __schedule+0x143f/0x4570 kernel/sched/core.c:6558 schedule+0xbf/0x180 kernel/sched/core.c:6634 percpu_rwsem_wait+0x3b9/0x450 kernel/locking/percpu-rwsem.c:162 __percpu_down_read+0xe6/0x130 kernel/locking/percpu-rwsem.c:177 percpu_down_read include/linux/percpu-rwsem.h:65 [inline] __sb_start_write include/linux/fs.h:1891 [inline] sb_start_write include/linux/fs.h:1966 [inline] write_mmp_block+0x2ee/0x390 fs/ext4/mmp.c:66 kmmpd+0x263/0xa70 fs/ext4/mmp.c:246 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8d32b1d0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8d32b9d0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/28: #0: ffffffff8d32b000 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8d32b000 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8d32b000 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6494 5 locks held by kworker/u4:2/33: #0: ffff888017e1e938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 #1: ffffc90000a9fd20 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 #2: ffffffff8e4ee490 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0xf1/0xb60 net/core/net_namespace.c:566 #3: ffffffff8e4fa7e8 (rtnl_mutex){+.+.}-{3:3}, at: default_device_exit_batch+0xe5/0x9d0 net/core/dev.c:11381 #4: ffffffff8d3305f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline] #4: ffffffff8d3305f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x4f0/0x930 kernel/rcu/tree_exp.h:962 2 locks held by klogd/3081: #0: ffff8880b8f3a9d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537 #1: ffff8880b8f27788 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x43d/0x770 kernel/sched/psi.c:1001 1 lock held by dhcpcd/3306: #0: ffffffff8e4fa7e8 (rtnl_mutex){+.+.}-{3:3}, at: __netlink_dump_start+0x12e/0x6c0 net/netlink/af_netlink.c:2301 2 locks held by getty/3400: #0: ffff88814aea7098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc900031262f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a7/0x1db0 drivers/tty/n_tty.c:2198 3 locks held by kworker/1:5/3687: #0: ffff88814acead38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 #1: ffffc900048bfd20 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 #2: ffffffff8e4fa7e8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xcc/0x16b0 net/ipv6/addrconf.c:4115 2 locks held by kworker/0:8/3693: #0: ffff888017c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 #1: ffffc900048dfd20 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 3 locks held by kworker/0:10/3766: #0: ffff88814acead38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 #1: ffffc90004b37d20 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 #2: ffffffff8e4fa7e8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xcc/0x16b0 net/ipv6/addrconf.c:4115 3 locks held by kworker/u4:13/3770: #0: ffff888017c79138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 #1: ffffc90004bd7d20 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 #2: ffffffff8e4fa7e8 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:263 3 locks held by kworker/1:11/3980: #0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 #1: ffffc9000333fd20 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 #2: ffffffff8e4fa7e8 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xa/0x20 net/switchdev/switchdev.c:104 1 lock held by syz-executor/4107: #0: ffff888054b0a0e0 (&type->s_umount_key#31){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:362 1 lock held by kmmpd-loop4/4494: #0: ffff888054b0a460 (sb_writers#4){++++}-{0:0}, at: kmmpd+0x263/0xa70 fs/ext4/mmp.c:246 1 lock held by syz-executor/6343: #0: ffffffff8d3305f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline] #0: ffffffff8d3305f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x360/0x930 kernel/rcu/tree_exp.h:962 1 lock held by syz-executor/6525: #0: ffffffff8e4fa7e8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] #0: ffffffff8e4fa7e8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7c1/0xff0 net/core/rtnetlink.c:6118 1 lock held by syz-executor/6608: #0: ffffffff8e4fa7e8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] #0: ffffffff8e4fa7e8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7c1/0xff0 net/core/rtnetlink.c:6118 2 locks held by syz-executor/6831: #0: ffffffff8e4ee490 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x378/0x5d0 net/core/net_namespace.c:477 #1: ffffffff8e4fa7e8 (rtnl_mutex){+.+.}-{3:3}, at: register_nexthop_notifier+0x80/0x270 net/ipv4/nexthop.c:3606 1 lock held by syz.4.553/6845: #0: ffffffff8e4fa7e8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] #0: ffffffff8e4fa7e8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7c1/0xff0 net/core/rtnetlink.c:6118 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.1.112-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 nmi_cpu_backtrace+0x4e1/0x560 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1ae/0x3f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xf88/0xfd0 kernel/hung_task.c:377 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 11 Comm: kworker/u4:1 Not tainted 6.1.112-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:__refcount_add include/linux/refcount.h:198 [inline] RIP: 0010:__refcount_inc include/linux/refcount.h:250 [inline] RIP: 0010:refcount_inc include/linux/refcount.h:267 [inline] RIP: 0010:__dev_hold include/linux/netdevice.h:3998 [inline] RIP: 0010:netdev_hold include/linux/netdevice.h:4036 [inline] RIP: 0010:dst_init+0x85/0x440 net/core/dst.c:52 Code: 48 89 44 24 10 48 8d bd b0 05 00 00 48 89 7c 24 08 be 04 00 00 00 e8 8a c7 42 f9 41 bc 01 00 00 00 f0 44 0f c1 a5 b0 05 00 00 <31> ff 44 89 e6 e8 f1 46 eb f8 45 85 e4 0f 84 9b 02 00 00 45 89 f7 RSP: 0018:ffffc900001e0798 EFLAGS: 00000206 RAX: ffff88807ce8f401 RBX: ffff88807ce8f3c0 RCX: ffffffff889f6b96 RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffff88801aed85b0 RBP: ffff88801aed8000 R08: dffffc0000000000 R09: ffffed10035db0b7 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000011 R13: ffff888057c3a540 R14: 0000000000000000 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055556b8c85c8 CR3: 000000000d08e000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: dst_alloc+0x155/0x190 net/core/dst.c:92 ip6_dst_alloc net/ipv6/route.c:345 [inline] icmp6_dst_alloc+0x7b/0x470 net/ipv6/route.c:3269 ndisc_send_skb+0x344/0x14e0 net/ipv6/ndisc.c:491 addrconf_rs_timer+0x357/0x610 net/ipv6/addrconf.c:3963 call_timer_fn+0x1ad/0x6b0 kernel/time/timer.c:1504 expire_timers kernel/time/timer.c:1549 [inline] __run_timers+0x67c/0x890 kernel/time/timer.c:1820 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1833 handle_softirqs+0x2ee/0xa40 kernel/softirq.c:571 __do_softirq kernel/softirq.c:605 [inline] invoke_softirq kernel/softirq.c:445 [inline] __irq_exit_rcu+0x157/0x240 kernel/softirq.c:654 irq_exit_rcu+0x5/0x20 kernel/softirq.c:666 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653 RIP: 0010:csd_lock_wait kernel/smp.c:424 [inline] RIP: 0010:smp_call_function_many_cond+0x1fae/0x3460 kernel/smp.c:998 Code: 2f 44 89 ee 83 e6 01 31 ff e8 ae 43 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 0a e8 39 40 0b 00 e9 1b ff ff ff f3 90 <42> 0f b6 04 2b 84 c0 75 14 41 f7 07 01 00 00 00 0f 84 fe fe ff ff RSP: 0018:ffffc900001075a0 EFLAGS: 00000293 RAX: ffffffff817f6f29 RBX: 1ffff110171c8595 RCX: ffff888017ed3b80 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90000107980 R08: ffffffff817f6ef2 R09: fffffbfff223ba45 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000800000000 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8880b8e42ca8 on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1166 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:1334 [inline] text_poke_bp_batch+0x5f9/0x940 arch/x86/kernel/alternative.c:1596 text_poke_flush arch/x86/kernel/alternative.c:1725 [inline] text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1732 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x12e/0x250 kernel/jump_label.c:205 static_key_enable+0x16/0x20 kernel/jump_label.c:218 toggle_allocation_gate+0xbf/0x480 mm/kfence/core.c:804 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295