INFO: task syz.8.4058:17166 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.8.4058 state:D stack:26488 pid:17166 tgid:17164 ppid:13203 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5387 [inline] __schedule+0x169e/0x54f0 kernel/sched/core.c:7188 __schedule_loop kernel/sched/core.c:7267 [inline] schedule+0x164/0x360 kernel/sched/core.c:7282 fuse_chan_wait_aborted+0x15b/0x250 fs/fuse/dev.c:2212 fuse_conn_destroy+0x1e7/0x3e0 fs/fuse/inode.c:1969 fuse_sb_destroy fs/fuse/inode.c:1988 [inline] fuse_kill_sb_anon+0x1ef/0x270 fs/fuse/inode.c:2001 deactivate_locked_super+0xbc/0x130 fs/super.c:476 vfs_get_super fs/super.c:1338 [inline] get_tree_nodev+0xd7/0x150 fs/super.c:1346 fuse_get_tree+0x2a0/0x3a0 fs/fuse/inode.c:1904 vfs_get_tree+0x92/0x2a0 fs/super.c:1754 fc_mount fs/namespace.c:1193 [inline] do_new_mount_fc fs/namespace.c:3758 [inline] do_new_mount+0x341/0xd30 fs/namespace.c:3834 do_mount fs/namespace.c:4167 [inline] __do_sys_mount fs/namespace.c:4399 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4376 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f944752c819 RSP: 002b:00007f944575d028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f94477a6090 RCX: 00007f944752c819 RDX: 00002000000020c0 RSI: 0000200000002080 RDI: 0000000000000000 RBP: 00007f94475c2c91 R08: 00002000000003c0 R09: 0000000000000000 R10: 0000000000000413 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f94477a6128 R14: 00007f94477a6090 R15: 00007ffe6debdf58 Showing all locks held in the system: 4 locks held by kworker/u8:0/12: #0: ffff88805c60c138 ((wq_completion)krds_cp_wq#1/0){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3280 [inline] #0: ffff88805c60c138 ((wq_completion)krds_cp_wq#1/0){+.+.}-{0:0}, at: process_scheduled_works+0xa2e/0x1910 kernel/workqueue.c:3399 #1: ffffc90000117c40 ((work_completion)(&(&cp->cp_conn_w)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3281 [inline] #1: ffffc90000117c40 ((work_completion)(&(&cp->cp_conn_w)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa69/0x1910 kernel/workqueue.c:3399 #2: ffff88803cb1da38 (&tc->t_conn_path_lock){+.+.}-{4:4}, at: rds_tcp_conn_path_connect+0x1cc/0x930 net/rds/tcp_connect.c:118 #3: ffffffff8e10c130 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:187 [inline] #3: ffffffff8e10c130 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_read_lock+0x27/0x60 include/linux/srcu.h:294 4 locks held by ksoftirqd/0/15: #0: ffffffff8de5f260 (local_bh){.+.+}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163 #1: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163 #2: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #2: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #2: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: process_backlog+0x271/0xc60 net/core/dev.c:6672 #3: ffff88801ea9b758 (&n->list_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #3: ffff88801ea9b758 (&n->list_lock){+.+.}-{3:3}, at: get_partial_node_bulk mm/slub.c:3736 [inline] #3: ffff88801ea9b758 (&n->list_lock){+.+.}-{3:3}, at: __refill_objects_node+0x87/0x560 mm/slub.c:7103 3 locks held by rcuc/1/29: #0: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163 #1: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #1: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #1: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: process_backlog+0x271/0xc60 net/core/dev.c:6672 #2: ffff888064f3d838 (&br->multicast_lock){+...}-{3:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #2: ffff888064f3d838 (&br->multicast_lock){+...}-{3:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #2: ffff888064f3d838 (&br->multicast_lock){+...}-{3:3}, at: class_rcu_constructor include/linux/rcupdate.h:1181 [inline] #2: ffff888064f3d838 (&br->multicast_lock){+...}-{3:3}, at: unwind_next_frame+0xa6/0x2550 arch/x86/kernel/unwind_orc.c:495 1 lock held by khungtaskd/39: #0: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6777 6 locks held by kworker/u8:13/2745: #0: ffff88801b296138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3280 [inline] #0: ffff88801b296138 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa2e/0x1910 kernel/workqueue.c:3399 #1: ffffc9000b637c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3281 [inline] #1: ffffc9000b637c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa69/0x1910 kernel/workqueue.c:3399 #2: ffffffff8f370ce0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:673 #3: ffff888052729160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #3: ffff888052729160 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:124 [inline] #3: ffff888052729160 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x129/0x420 net/devlink/core.c:555 #4: ffff888029b84310 (&devlink->lock_key#12){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:292 [inline] #4: ffff888029b84310 (&devlink->lock_key#12){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:125 [inline] #4: ffff888029b84310 (&devlink->lock_key#12){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x142/0x420 net/devlink/core.c:555 #5: ffff88805d25de70 (&sb->s_type->i_mutex_key#4/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1074 [inline] #5: ffff88805d25de70 (&sb->s_type->i_mutex_key#4/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2914 [inline] #5: ffff88805d25de70 (&sb->s_type->i_mutex_key#4/1){+.+.}-{4:4}, at: start_dirop+0x4f/0x90 fs/namei.c:2938 2 locks held by dhcpcd/5489: #0: ffff8880434ae928 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: netlink_dump+0xe2/0xe10 net/netlink/af_netlink.c:2267 #1: ffffffff8f37f5f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8f37f5f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dumpit+0x92/0x200 net/core/rtnetlink.c:6862 2 locks held by getty/5589: #0: ffff888037ceb0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003cbe2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13a0 drivers/tty/n_tty.c:2211 2 locks held by kworker/1:5/5840: #0: ffff88801a053938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3280 [inline] #0: ffff88801a053938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa2e/0x1910 kernel/workqueue.c:3399 #1: ffffc90004a47c40 ((work_completion)(&m->mpeg_thread)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3281 [inline] #1: ffffc90004a47c40 ((work_completion)(&m->mpeg_thread)){+.+.}-{0:0}, at: process_scheduled_works+0xa69/0x1910 kernel/workqueue.c:3399 6 locks held by kworker/u8:8/16079: #0: ffff88801a094138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3280 [inline] #0: ffff88801a094138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa2e/0x1910 kernel/workqueue.c:3399 #1: ffffc9000d107c40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3281 [inline] #1: ffffc9000d107c40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa69/0x1910 kernel/workqueue.c:3399 #2: ffff888020aee310 (&devlink->lock_key#2){+.+.}-{4:4}, at: nsim_dev_trap_report_work+0x57/0xbc0 drivers/net/netdevsim/dev.c:909 #3: ffff88805cebbd20 (&nsim_trap_data->trap_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #3: ffff88805cebbd20 (&nsim_trap_data->trap_lock){+.+.}-{3:3}, at: nsim_dev_trap_report drivers/net/netdevsim/dev.c:862 [inline] #3: ffff88805cebbd20 (&nsim_trap_data->trap_lock){+.+.}-{3:3}, at: nsim_dev_trap_report_work+0x1ad/0xbc0 drivers/net/netdevsim/dev.c:922 #4: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #4: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #4: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] #4: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e0/0x400 kernel/locking/spinlock_rt.c:57 #5: ffff88801ea9b758 (&n->list_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #5: ffff88801ea9b758 (&n->list_lock){+.+.}-{3:3}, at: get_partial_node_bulk mm/slub.c:3736 [inline] #5: ffff88801ea9b758 (&n->list_lock){+.+.}-{3:3}, at: __refill_objects_node+0x87/0x560 mm/slub.c:7103 6 locks held by kworker/u8:19/16649: #0: ffff88801a094138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3280 [inline] #0: ffff88801a094138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa2e/0x1910 kernel/workqueue.c:3399 #1: ffffc9000d06fc40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3281 [inline] #1: ffffc9000d06fc40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa69/0x1910 kernel/workqueue.c:3399 #2: ffff888061118310 (&devlink->lock_key#9){+.+.}-{4:4}, at: nsim_dev_trap_report_work+0x57/0xbc0 drivers/net/netdevsim/dev.c:909 #3: ffff88805d499920 (&nsim_trap_data->trap_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #3: ffff88805d499920 (&nsim_trap_data->trap_lock){+.+.}-{3:3}, at: nsim_dev_trap_report drivers/net/netdevsim/dev.c:862 [inline] #3: ffff88805d499920 (&nsim_trap_data->trap_lock){+.+.}-{3:3}, at: nsim_dev_trap_report_work+0x1ad/0xbc0 drivers/net/netdevsim/dev.c:922 #4: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #4: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #4: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] #4: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e0/0x400 kernel/locking/spinlock_rt.c:57 #5: ffff88801ea9b758 (&n->list_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #5: ffff88801ea9b758 (&n->list_lock){+.+.}-{3:3}, at: get_partial_node_bulk mm/slub.c:3736 [inline] #5: ffff88801ea9b758 (&n->list_lock){+.+.}-{3:3}, at: __refill_objects_node+0x87/0x560 mm/slub.c:7103 1 lock held by syz-executor/16918: #0: ffffffff8f37f5f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f37f5f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8f37f5f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x883/0x1bb0 net/core/rtnetlink.c:4107 1 lock held by syz.8.4058/17166: #0: ffff88803258c0d0 (&type->s_umount_key#100/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xac0 fs/super.c:345 4 locks held by syz-executor/17367: #0: ffff88804e574f80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:500 [inline] #0: ffff88804e574f80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x5a0 net/bluetooth/hci_core.c:2716 #1: ffff88804e5740b0 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x640/0x10e0 net/bluetooth/hci_sync.c:5356 #2: ffffffff8f50b0f8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2151 [inline] #2: ffffffff8f50b0f8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x260 net/bluetooth/hci_conn.c:2667 #3: ffff88803b6df370 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x92/0x570 net/bluetooth/l2cap_core.c:1777 2 locks held by syz-executor/17373: #0: ffff88813fffbb98 (&zone->lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #0: ffff88813fffbb98 (&zone->lock){+.+.}-{3:3}, at: free_one_page+0x43/0x250 mm/page_alloc.c:1554 #1: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #1: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #1: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] #1: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e0/0x400 kernel/locking/spinlock_rt.c:57 2 locks held by syz-executor/17385: #0: ffffffff8f8d2b08 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8f8d2b08 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8f8d2b08 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8f37f5f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8f37f5f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8f37f5f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x883/0x1bb0 net/core/rtnetlink.c:4107 6 locks held by syz-executor/17416: #0: ffffffff8f370ce0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:575 #1: ffffffff8f37f5f8 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x2d7/0x840 net/ipv4/ip_tunnel.c:1146 #2: ffff88803ab3cc80 (&net->mpls.platform_mutex){+.+.}-{4:4}, at: mpls_dev_notify+0x78/0xd10 net/mpls/af_mpls.c:1644 #3: ffff8880b88463e0 ((&pcs->lock)){+.+.}-{3:3}, at: alloc_from_pcs mm/slub.c:4743 [inline] #3: ffff8880b88463e0 ((&pcs->lock)){+.+.}-{3:3}, at: slab_alloc_node mm/slub.c:4883 [inline] #3: ffff8880b88463e0 ((&pcs->lock)){+.+.}-{3:3}, at: kmem_cache_alloc_node_noprof+0x304/0x6e0 mm/slub.c:4950 #4: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #4: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #4: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: __rt_spin_trylock kernel/locking/spinlock_rt.c:110 [inline] #4: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: rt_spin_trylock+0x10c/0x2b0 kernel/locking/spinlock_rt.c:118 #5: ffff88801ea9d658 (&barn->lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #5: ffff88801ea9d658 (&barn->lock){+.+.}-{3:3}, at: barn_get_empty_sheaf mm/slub.c:3082 [inline] #5: ffff88801ea9d658 (&barn->lock){+.+.}-{3:3}, at: __pcs_replace_empty_main+0x1e8/0x720 mm/slub.c:4635 2 locks held by syz-executor/17421: #0: ffffffff8f370ce0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:575 #1: ffffffff8f37f5f8 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x2d7/0x840 net/ipv4/ip_tunnel.c:1146 1 lock held by syz-executor/17438: #0: ffffffff8f37f5f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f37f5f8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x404/0x1ad0 net/ipv4/devinet.c:978 1 lock held by syz-executor/17441: #0: ffffffff8f37f5f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f37f5f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8f37f5f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x883/0x1bb0 net/core/rtnetlink.c:4107 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 39 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xfd3/0x1030 kernel/hung_task.c:561 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 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: 29 Comm: rcuc/1 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 RIP: 0010:unwind_next_frame+0x114/0x2550 arch/x86/kernel/unwind_orc.c:498 Code: 1f c6 05 0b f6 ff 0d 01 48 c7 c7 60 b3 49 8b be 48 03 00 00 48 c7 c2 a0 b3 49 8b e8 86 ac 29 00 4c 89 64 24 78 48 89 5c 24 70 <49> 8d 5e 50 48 89 d8 48 c1 e8 03 48 89 44 24 40 80 3c 28 00 74 08 RSP: 0018:ffffc90000a3e758 EFLAGS: 00000202 RAX: 0000000000000001 RBX: ffffffff89081d2f RCX: 0000000080000001 RDX: 00000000beb03aa1 RSI: ffffffff8ba83cc0 RDI: ffffffff8ba83c80 RBP: dffffc0000000000 R08: ffffffff81770226 R09: ffffffff8dfc8100 R10: ffffc90000a3e878 R11: ffffffff81afc300 R12: ffffc90000a3e860 R13: 1ffff92000147d05 R14: ffffc90000a3e828 R15: ffffffff81770226 FS: 0000000000000000(0000) GS:ffff8881261c0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055a3a8c5e000 CR3: 000000000ddb6000 CR4: 00000000003526f0 Call Trace: arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4569 [inline] slab_alloc_node mm/slub.c:4898 [inline] kmem_cache_alloc_noprof+0x33b/0x680 mm/slub.c:4905 skb_ext_maybe_cow net/core/skbuff.c:7063 [inline] skb_ext_add+0x1b6/0x8f0 net/core/skbuff.c:7138 nf_bridge_unshare net/bridge/br_netfilter_hooks.c:170 [inline] br_nf_forward_ip+0xc3/0xa30 net/bridge/br_netfilter_hooks.c:682 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:619 nf_hook include/linux/netfilter.h:273 [inline] NF_HOOK+0x23e/0x3f0 include/linux/netfilter.h:316 __br_forward+0x397/0x540 net/bridge/br_forward.c:115 deliver_clone net/bridge/br_forward.c:131 [inline] maybe_deliver net/bridge/br_forward.c:191 [inline] br_flood+0x6ee/0xb80 net/bridge/br_forward.c:238 br_handle_frame_finish+0x1521/0x1c80 net/bridge/br_input.c:229 br_nf_hook_thresh+0x3dd/0x4c0 net/bridge/br_netfilter_hooks.c:-1 br_nf_pre_routing_finish_ipv6+0x91f/0xc30 net/bridge/br_netfilter_ipv6.c:-1 NF_HOOK include/linux/netfilter.h:318 [inline] br_nf_pre_routing_ipv6+0x374/0x6f0 net/bridge/br_netfilter_ipv6.c:183 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_bridge_pre net/bridge/br_input.c:291 [inline] br_handle_frame+0x127a/0x1510 net/bridge/br_input.c:442 __netif_receive_skb_core+0x98f/0x3170 net/core/dev.c:6096 __netif_receive_skb_one_core net/core/dev.c:6207 [inline] __netif_receive_skb net/core/dev.c:6322 [inline] process_backlog+0x35e/0xc60 net/core/dev.c:6673 __napi_poll+0xab/0x550 net/core/dev.c:7737 napi_poll net/core/dev.c:7800 [inline] net_rx_action+0x696/0xe00 net/core/dev.c:7957 handle_softirqs+0x1de/0x6d0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] __local_bh_enable_ip+0x170/0x2b0 kernel/softirq.c:302 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_do_batch kernel/rcu/tree.c:2636 [inline] rcu_core kernel/rcu/tree.c:2869 [inline] rcu_cpu_kthread+0x9e8/0x1470 kernel/rcu/tree.c:2957 smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245