INFO: task syz.4.1290:16250 blocked for more than 143 seconds. Not tainted 6.12.0-rc6-syzkaller-00318-ga9cda7c0ffed #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.1290 state:D stack:24696 pid:16250 tgid:16248 ppid:15661 flags:0x00000006 Call Trace: context_switch kernel/sched/core.c:5328 [inline] __schedule+0x184f/0x4c30 kernel/sched/core.c:6690 __schedule_loop kernel/sched/core.c:6767 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6782 schedule_timeout+0xb0/0x310 kernel/time/timer.c:2591 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common+0x3ed/0x6e0 kernel/sched/completion.c:116 wait_for_common kernel/sched/completion.c:127 [inline] wait_for_completion_state+0x1c/0x40 kernel/sched/completion.c:264 coredump_wait fs/coredump.c:418 [inline] do_coredump+0xa5d/0x2ec0 fs/coredump.c:575 get_signal+0x13fc/0x1740 kernel/signal.c:2903 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f69bba403c0 RSP: 002b:00007f69bc9b9b38 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 0000000000000000 RBX: 00007f69bbd36060 RCX: 00007f69bbb7e719 RDX: 00007f69bc9b9b40 RSI: 00007f69bc9b9c70 RDI: 000000000000000b RBP: 00007f69bbd36058 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f69bbd36064 R13: 0000000000000000 R14: 00007f69bbe5f940 R15: 00007f69bbe5fa28 Showing all locks held in the system: 1 lock held by ksoftirqd/1/24: 1 lock held by khungtaskd/30: #0: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6720 2 locks held by dhcpcd/5509: #0: ffff888061eaf6c8 (nlk_cb_mutex-ROUTE){+.+.}-{3:3}, at: __netlink_dump_start+0x119/0x790 net/netlink/af_netlink.c:2405 #1: ffffffff8fcd3948 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #1: ffffffff8fcd3948 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_dumpit+0x99/0x200 net/core/rtnetlink.c:6534 2 locks held by getty/5599: #0: ffff88814ddcf0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900032532f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 4 locks held by kworker/u8:13/12462: #0: ffff88801baed948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801baed948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc9000d16fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc9000d16fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcc6e10 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x16a/0xcc0 net/core/net_namespace.c:580 #3: ffffffff8fcd3948 (rtnl_mutex){+.+.}-{3:3}, at: wg_netns_pre_exit+0x1f/0x1e0 drivers/net/wireguard/device.c:414 2 locks held by syz.4.1290/16249: #0: ffffffff8fcc6e10 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x328/0x570 net/core/net_namespace.c:490 #1: ffffffff8fcd3948 (rtnl_mutex){+.+.}-{3:3}, at: fib_net_exit_batch+0x20/0x90 net/ipv4/fib_frontend.c:1638 7 locks held by syz-executor/16333: #0: ffff888023d46420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2931 [inline] #0: ffff888023d46420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x225/0xd30 fs/read_write.c:679 #1: ffff888062722888 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1ea/0x500 fs/kernfs/file.c:325 #2: ffff888027f6f3c8 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20e/0x500 fs/kernfs/file.c:326 #3: ffffffff8f5717a8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xfc/0x480 drivers/net/netdevsim/bus.c:216 #4: ffff88807b7d70e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] #4: ffff88807b7d70e8 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1095 [inline] #4: ffff88807b7d70e8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xce/0x7c0 drivers/base/dd.c:1293 #5: ffff888052881250 (&devlink->lock_key#20){+.+.}-{3:3}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1675 #6: ffffffff8fcd3948 (rtnl_mutex){+.+.}-{3:3}, at: unregister_nexthop_notifier+0x17/0x40 net/ipv4/nexthop.c:3913 3 locks held by syz-executor/16367: #0: ffffffff8fcc6e10 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x328/0x570 net/core/net_namespace.c:490 #1: ffffffff8fcd3948 (rtnl_mutex){+.+.}-{3:3}, at: default_device_exit_batch+0xe9/0xaa0 net/core/dev.c:11938 #2: ffffffff8e7d1d90 (cpu_hotplug_lock){++++}-{0:0}, at: flush_all_backlogs net/core/dev.c:6029 [inline] #2: ffffffff8e7d1d90 (cpu_hotplug_lock){++++}-{0:0}, at: unregister_netdevice_many_notify+0x5ea/0x1da0 net/core/dev.c:11388 2 locks held by syz-executor/16371: #0: ffffffff8fcc6e10 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x328/0x570 net/core/net_namespace.c:490 #1: ffffffff8fcd3948 (rtnl_mutex){+.+.}-{3:3}, at: setup_net+0x602/0x9e0 net/core/net_namespace.c:378 2 locks held by syz-executor/16403: #0: ffffffff8fcc6e10 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x328/0x570 net/core/net_namespace.c:490 #1: ffffffff8fcd3948 (rtnl_mutex){+.+.}-{3:3}, at: wg_netns_pre_exit+0x1f/0x1e0 drivers/net/wireguard/device.c:414 2 locks held by syz-executor/16404: #0: ffffffff8fcc6e10 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x328/0x570 net/core/net_namespace.c:490 #1: ffffffff8fcd3948 (rtnl_mutex){+.+.}-{3:3}, at: ppp_exit_net+0xe3/0x3d0 drivers/net/ppp/ppp_generic.c:1146 2 locks held by syz-executor/16407: #0: ffffffff8fcc6e10 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x328/0x570 net/core/net_namespace.c:490 #1: ffffffff8fcd3948 ( rtnl_mutex ){+.+.}-{3:3} , at: wg_netns_pre_exit+0x1f/0x1e0 drivers/net/wireguard/device.c:414 2 locks held by syz-executor/16423: #0: ffffffff8fcc6e10 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x328/0x570 net/core/net_namespace.c:490 #1: ffffffff8fcd3948 (rtnl_mutex){+.+.}-{3:3}, at: ip_tunnel_init_net+0x20e/0x720 net/ipv4/ip_tunnel.c:1159 1 lock held by syz-executor/16428: #0: ffffffff8fcd3948 (rtnl_mutex){+.+.}-{3:3}, at: __tun_chr_ioctl+0x48c/0x2400 drivers/net/tun.c:3121 2 locks held by syz-executor/16436: #0: ffffffff8fcc6e10 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x328/0x570 net/core/net_namespace.c:490 #1: ffffffff8fcd3948 (rtnl_mutex){+.+.}-{3:3}, at: ip_tunnel_init_net+0x20e/0x720 net/ipv4/ip_tunnel.c:1159 2 locks held by syz-executor/16439: #0: ffffffff8fcc6e10 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x328/0x570 net/core/net_namespace.c:490 #1: ffffffff8fcd3948 (rtnl_mutex){+.+.}-{3:3}, at: ip_tunnel_init_net+0x20e/0x720 net/ipv4/ip_tunnel.c:1159 2 locks held by syz-executor/16442: #0: ffffffff8fcc6e10 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x328/0x570 net/core/net_namespace.c:490 #1: ffffffff8fcd3948 (rtnl_mutex){+.+.}-{3:3}, at: ip_tunnel_init_net+0x20e/0x720 net/ipv4/ip_tunnel.c:1159 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc6-syzkaller-00318-ga9cda7c0ffed #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xff4/0x1040 kernel/hung_task.c:379 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 24 Comm: ksoftirqd/1 Not tainted 6.12.0-rc6-syzkaller-00318-ga9cda7c0ffed #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024 RIP: 0010:check_preemption_disabled+0x27/0x120 lib/smp_processor_id.c:16 Code: 90 90 90 41 57 41 56 41 54 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 44 24 08 65 8b 1d 0c 42 3c 74 65 8b 05 01 42 3c 74 ff ff ff 7f 74 26 65 48 8b 04 25 28 00 00 00 48 3b 44 24 08 0f RSP: 0018:ffffc900001e6120 EFLAGS: 00000082 RAX: 0000000080000100 RBX: 0000000000000001 RCX: 0000000080000100 RDX: ffff88801d2e8000 RSI: ffffffff8c0adc40 RDI: ffffffff8c610a60 RBP: 0000000000000000 R08: ffffffff8a6d109c R09: ffffc900001e6450 R10: ffffc900001e6440 R11: fffff5200003cc56 R12: 0000000000000246 R13: ffff88801d2e8000 R14: 00000000ffffffff R15: ffffffff8e937da0 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f574a5dd256 CR3: 000000000e734000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lockdep_recursion_finish kernel/locking/lockdep.c:467 [inline] lock_is_held_type+0x101/0x190 kernel/locking/lockdep.c:5898 __find_rr_leaf+0x395/0x8e0 net/ipv6/route.c:797 find_rr_leaf net/ipv6/route.c:853 [inline] rt6_select net/ipv6/route.c:897 [inline] fib6_table_lookup+0x413/0xbb0 net/ipv6/route.c:2195 ip6_pol_route+0x273/0x15d0 net/ipv6/route.c:2231 pol_lookup_func include/net/ip6_fib.h:616 [inline] fib6_rule_lookup+0x58c/0x790 net/ipv6/fib6_rules.c:117 ip6_route_input_lookup net/ipv6/route.c:2300 [inline] ip6_route_input+0x859/0xd90 net/ipv6/route.c:2596 ip6_rcv_finish+0x144/0x180 net/ipv6/ip6_input.c:77 ip_sabotage_in+0x203/0x290 net/bridge/br_netfilter_hooks.c:1018 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xc3/0x220 net/netfilter/core.c:626 nf_hook include/linux/netfilter.h:269 [inline] NF_HOOK+0x29e/0x450 include/linux/netfilter.h:312 __netif_receive_skb_one_core net/core/dev.c:5670 [inline] __netif_receive_skb+0x1ea/0x650 net/core/dev.c:5783 netif_receive_skb_internal net/core/dev.c:5869 [inline] netif_receive_skb+0x1e8/0x890 net/core/dev.c:5928 NF_HOOK+0x9e/0x400 include/linux/netfilter.h:314 br_handle_frame_finish+0x18ed/0x1fe0 br_nf_hook_thresh+0x472/0x590 br_nf_pre_routing_finish_ipv6+0xaa0/0xdd0 NF_HOOK include/linux/netfilter.h:314 [inline] br_nf_pre_routing_ipv6+0x379/0x770 net/bridge/br_netfilter_ipv6.c:184 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_bridge_pre net/bridge/br_input.c:277 [inline] br_handle_frame+0x9fd/0x1530 net/bridge/br_input.c:424 __netif_receive_skb_core+0x13e8/0x4570 net/core/dev.c:5564 __netif_receive_skb_one_core net/core/dev.c:5668 [inline] __netif_receive_skb+0x12f/0x650 net/core/dev.c:5783 process_backlog+0x662/0x15b0 net/core/dev.c:6115 __napi_poll+0xcb/0x490 net/core/dev.c:6779 napi_poll net/core/dev.c:6848 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:6970 handle_softirqs+0x2c5/0x980 kernel/softirq.c:554 run_ksoftirqd+0xca/0x130 kernel/softirq.c:927 smpboot_thread_fn+0x544/0xa30 kernel/smpboot.c:164 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244