INFO: task syz.5.3310:18429 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.5.3310 state:D stack:25176 pid:18429 tgid:18428 ppid:12322 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1295/0x67a0 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7283 schedule_timeout+0x1b2/0x280 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common+0x2e7/0x4c0 kernel/sched/completion.c:121 __flush_work+0x7c7/0xcb0 kernel/workqueue.c:4366 p9_mux_poll_stop net/9p/trans_fd.c:140 [inline] p9_conn_destroy net/9p/trans_fd.c:804 [inline] p9_fd_close+0x299/0x5a0 net/9p/trans_fd.c:840 p9_client_create+0x678/0xd40 net/9p/client.c:937 v9fs_session_init+0x3c/0xd20 fs/9p/v9fs.c:446 v9fs_get_tree+0xb8/0xb50 fs/9p/vfs_super.c:97 vfs_get_tree+0x92/0x320 fs/super.c:1754 fc_mount fs/namespace.c:1193 [inline] do_new_mount_fc fs/namespace.c:3758 [inline] do_new_mount fs/namespace.c:3834 [inline] path_mount+0x7d0/0x23d0 fs/namespace.c:4154 do_mount fs/namespace.c:4167 [inline] __do_sys_mount fs/namespace.c:4383 [inline] __se_sys_mount fs/namespace.c:4360 [inline] __x64_sys_mount+0x293/0x310 fs/namespace.c:4360 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3714d9ce59 RSP: 002b:00007f3715bf4028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f3715015fa0 RCX: 00007f3714d9ce59 RDX: 0000200000000300 RSI: 0000200000000040 RDI: 0000000000000000 RBP: 00007f3714e32d6f R08: 00002000000004c0 R09: 0000000000000000 R10: 0000000000000084 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f3715016038 R14: 00007f3715015fa0 R15: 00007ffcb44ac068 INFO: task syz.6.3359:18680 blocked for more than 144 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.3359 state:D stack:27896 pid:18680 tgid:18678 ppid:12315 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1295/0x67a0 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7283 schedule_timeout+0x1b2/0x280 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common+0x2e7/0x4c0 kernel/sched/completion.c:121 __flush_work+0x7c7/0xcb0 kernel/workqueue.c:4366 p9_mux_poll_stop net/9p/trans_fd.c:140 [inline] p9_conn_destroy net/9p/trans_fd.c:804 [inline] p9_fd_close+0x299/0x5a0 net/9p/trans_fd.c:840 p9_client_create+0x678/0xd40 net/9p/client.c:937 v9fs_session_init+0x3c/0xd20 fs/9p/v9fs.c:446 v9fs_get_tree+0xb8/0xb50 fs/9p/vfs_super.c:97 vfs_get_tree+0x92/0x320 fs/super.c:1754 fc_mount fs/namespace.c:1193 [inline] do_new_mount_fc fs/namespace.c:3758 [inline] do_new_mount fs/namespace.c:3834 [inline] path_mount+0x7d0/0x23d0 fs/namespace.c:4154 do_mount fs/namespace.c:4167 [inline] __do_sys_mount fs/namespace.c:4383 [inline] __se_sys_mount fs/namespace.c:4360 [inline] __x64_sys_mount+0x293/0x310 fs/namespace.c:4360 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f41ac99ce59 RSP: 002b:00007f41ad87b028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f41acc15fa0 RCX: 00007f41ac99ce59 RDX: 0000200000000040 RSI: 0000200000000000 RDI: 0000000000000000 RBP: 00007f41aca32d6f R08: 0000200000000280 R09: 0000000000000000 R10: 0000000000200000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f41acc16038 R14: 00007f41acc15fa0 R15: 00007fff8e4fa1c8 Showing all locks held in the system: 1 lock held by pool_workqueue_/3: #0: ffffffff8e7f12e8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343 1 lock held by khungtaskd/30: #0: ffffffff8e7e57a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e7e57a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8e7e57a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775 2 locks held by kworker/1:1/42: #0: ffff88813fe5b140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3289 #1: ffffc90000b27d08 (p9_poll_work){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3290 2 locks held by getty/5365: #0: ffff8880382900a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14f0 drivers/tty/n_tty.c:2211 2 locks held by kworker/u8:9/5833: #0: ffff88801e74c940 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3289 #1: ffffc90004cafd08 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3290 4 locks held by udevd/6321: #0: ffff88804dbfc2d8 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x1270 fs/seq_file.c:183 #1: ffff88807e85c480 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:172 #2: ffff88802c3b1a58 (kn->active#27){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff88802c3b1a58 (kn->active#27){++++}-{0:0}, at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:173 #3: ffff8880513581d8 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:1045 [inline] #3: ffff8880513581d8 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 3 locks held by kworker/u8:10/8682: #0: ffff8880b843b2a0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:660 [inline] #0: ffff8880b843b2a0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x88/0x140 kernel/sched/core.c:644 #1: ffff8880b8524648 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:225 [inline] #1: ffff8880b8524648 (psi_seq){-.-.}-{0:0}, at: __schedule+0x2f15/0x67a0 kernel/sched/core.c:7183 #2: ffff8880b8526358 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x124/0x1d0 kernel/time/timer.c:1004 4 locks held by kworker/0:2/9980: #0: ffff888022e8c140 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3289 #1: ffffc9000340fd08 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3290 #2: ffff88802b6a91d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #2: ffff88802b6a91d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899 #3: ffff8880513581d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #3: ffff8880513581d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1076 3 locks held by syz.3.3372/18769: #0: ffff88808a0d0ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0xb0 net/bluetooth/hci_core.c:500 #1: ffff88808a0d00b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x35c/0x1240 net/bluetooth/hci_sync.c:5356 #2: ffffffff90894320 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2151 [inline] #2: ffffffff90894320 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xbb/0x280 net/bluetooth/hci_conn.c:2734 1 lock held by syz.4.3591/19837: #0: ffffffff8e7f11b8 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6d0 kernel/rcu/tree.c:3828 4 locks held by syz.9.3763/20474: #0: ffff88807f12cea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0xb0 net/bluetooth/hci_core.c:500 #1: ffff88807f12c0b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x35c/0x1240 net/bluetooth/hci_sync.c:5356 #2: ffffffff90894320 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2151 [inline] #2: ffffffff90894320 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xbb/0x280 net/bluetooth/hci_conn.c:2734 #3: ffff888077ca22f8 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x95/0x710 net/bluetooth/l2cap_core.c:1777 3 locks held by syz-executor/20495: #0: ffffffff905f4948 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x451/0x7c0 net/core/net_namespace.c:575 #1: ffffffff9060d6a0 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline] #1: ffffffff9060d6a0 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x7ec/0xab0 net/core/net_namespace.c:248 #2: ffffffff8e7f12e8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343 1 lock held by syz.7.3770/20512: #0: ffffffff9060d6a0 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff9060d6a0 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x220 drivers/net/tun.c:3438 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x1d7/0x230 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+0x141/0x190 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xcb1/0x1030 kernel/hung_task.c:561 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 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: 1035 Comm: kworker/u8:6 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Workqueue: krds_cp_wq#5/0 rds_connect_worker RIP: 0010:__lock_acquire+0x139/0x2630 kernel/locking/lockdep.c:5170 Code: 00 44 39 e8 75 09 4d 85 e4 0f 85 99 05 00 00 48 8b 04 24 44 89 ea 66 81 e2 ff 1f 48 01 c3 0f b7 43 20 4c 89 53 10 4c 89 63 18 <66> 25 00 e0 09 d0 31 d2 66 89 43 20 48 8b 84 24 b0 00 00 00 48 89 RSP: 0018:ffffc9000517f6f8 EFLAGS: 00000082 RAX: 0000000000000007 RBX: ffff888028883158 RCX: 0000000000000005 RDX: 0000000000000007 RSI: ffff888028883130 RDI: ffffffff8e7e57a0 RBP: ffff888028882500 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff8e7e57a0 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000007 R14: 0000000000000002 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88812436d000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c4011ed CR3: 0000000022bf2000 CR4: 00000000003526f0 Call Trace: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x1b1/0x370 kernel/locking/lockdep.c:5825 rcu_lock_acquire include/linux/rcupdate.h:300 [inline] rcu_read_lock include/linux/rcupdate.h:838 [inline] __ipv6_chk_addr_and_flags+0x9a/0x750 net/ipv6/addrconf.c:1987 ipv6_chk_addr_and_flags net/ipv6/addrconf.c:2022 [inline] ipv6_chk_addr+0x3a/0x50 net/ipv6/addrconf.c:1963 __inet6_bind+0x1236/0x1b40 net/ipv6/af_inet6.c:367 inet6_bind_sk net/ipv6/af_inet6.c:449 [inline] inet6_bind_sk net/ipv6/af_inet6.c:426 [inline] inet6_bind+0xdb/0x120 net/ipv6/af_inet6.c:455 kernel_bind+0xff/0x160 net/socket.c:3660 rds_tcp_conn_path_connect+0x554/0xaa0 net/rds/tcp_connect.c:175 rds_connect_worker+0x1b4/0x2d0 net/rds/threads.c:176 process_one_work+0xa0e/0x1980 kernel/workqueue.c:3314 process_scheduled_works kernel/workqueue.c:3397 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3478 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245