INFO: task syz.4.2581:14179 blocked for more than 143 seconds. Not tainted 6.15.0-rc2-syzkaller-00682-gcd7276ecac9c #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.2581 state:D stack:27320 pid:14179 tgid:14178 ppid:5835 task_flags:0x400040 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b88/0x5240 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x163/0x360 kernel/sched/core.c:6860 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917 __mutex_lock_common kernel/locking/mutex.c:678 [inline] __mutex_lock+0x805/0x10c0 kernel/locking/mutex.c:746 nfsd_nl_threads_get_doit+0x1c7/0x7e0 fs/nfsd/nfsctl.c:1713 genl_family_rcv_msg_doit net/netlink/genetlink.c:1115 [inline] genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] genl_rcv_msg+0xb38/0xf00 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x208/0x480 net/netlink/af_netlink.c:2534 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline] netlink_unicast+0x7f8/0x9a0 net/netlink/af_netlink.c:1339 netlink_sendmsg+0x8c3/0xcd0 net/netlink/af_netlink.c:1883 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:727 ____sys_sendmsg+0x523/0x860 net/socket.c:2566 ___sys_sendmsg net/socket.c:2620 [inline] __sys_sendmsg+0x271/0x360 net/socket.c:2652 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f346238e969 RSP: 002b:00007f34601f6038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f34625b5fa0 RCX: 00007f346238e969 RDX: 0000000000000010 RSI: 0000200000000040 RDI: 0000000000000003 RBP: 00007f3462410ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f34625b5fa0 R15: 00007ffc599da088 Showing all locks held in the system: 2 locks held by ksoftirqd/1/23: 1 lock held by khungtaskd/31: #0: ffffffff8ed3df20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8ed3df20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8ed3df20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x30/0x180 kernel/locking/lockdep.c:6764 6 locks held by kworker/u8:5/1139: #0: ffff88801bef6148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801bef6148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319 #1: ffffc90003bf7c60 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90003bf7c60 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319 #2: ffffffff900f1e50 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0x100/0x930 net/core/net_namespace.c:662 #3: ffff88805f4690e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline] #3: ffff88805f4690e8 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline] #3: ffff88805f4690e8 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x13d/0x450 net/devlink/core.c:506 #4: ffff888058fd7250 (&devlink->lock_key#22){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:276 [inline] #4: ffff888058fd7250 (&devlink->lock_key#22){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:109 [inline] #4: ffff888058fd7250 (&devlink->lock_key#22){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x14f/0x450 net/devlink/core.c:506 #5: ffffffff900fe988 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #5: ffffffff900fe988 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x271/0x320 net/core/dev.c:2141 2 locks held by getty/5590: #0: ffff888034d920a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900030062f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x5bb/0x1700 drivers/tty/n_tty.c:2222 2 locks held by kworker/u8:10/7422: 3 locks held by kworker/1:7/8767: #0: ffff88801b080d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801b080d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319 #1: ffffc9000324fc60 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000324fc60 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319 #2: ffff888041f00240 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x316/0x3f10 drivers/net/netdevsim/fib.c:1490 2 locks held by syz.0.2562/14062: #0: ffffffff90163650 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8f0139c8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x135/0x1870 fs/nfsd/nfsctl.c:1923 2 locks held by syz.4.2581/14179: #0: ffffffff90163650 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8f0139c8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_get_doit+0x1c7/0x7e0 fs/nfsd/nfsctl.c:1713 7 locks held by syz-executor/17283: #0: ffff888034fd6420 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3041 [inline] #0: ffff888034fd6420 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x23f/0xd10 fs/read_write.c:680 #1: ffff888045715888 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1e2/0x510 fs/kernfs/file.c:325 #2: ffff888144ba0698 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x206/0x510 fs/kernfs/file.c:326 #3: ffffffff8f9981c8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xfe/0x490 drivers/net/netdevsim/bus.c:216 #4: ffff88804916f0e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline] #4: ffff88804916f0e8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1095 [inline] #4: ffff88804916f0e8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xce/0x7c0 drivers/base/dd.c:1293 #5: ffff88804916c250 (&devlink->lock_key#21){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1675 #6: ffffffff900fe988 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0x10d/0x690 drivers/net/netdevsim/netdev.c:1059 1 lock held by syz-executor/17334: #0: ffffffff8ed43438 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline] #0: ffffffff8ed43438 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x384/0x830 kernel/rcu/tree_exp.h:998 2 locks held by syz-executor/17397: #0: ffffffff900f1e50 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x328/0x570 net/core/net_namespace.c:570 #1: ffffffff900fe988 (rtnl_mutex){+.+.}-{4:4}, at: wg_netns_pre_exit+0x1f/0x1e0 drivers/net/wireguard/device.c:416 1 lock held by syz.6.3158/17408: #0: ffffffff8ed43438 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #0: ffffffff8ed43438 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x454/0x830 kernel/rcu/tree_exp.h:998 4 locks held by dhcpcd-run-hook/17419: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc2-syzkaller-00682-gcd7276ecac9c #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x4ab/0x4e0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 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+0x1058/0x10a0 kernel/hung_task.c:437 kthread+0x7b7/0x940 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: 5840 Comm: kworker/u9:2 Not tainted 6.15.0-rc2-syzkaller-00682-gcd7276ecac9c #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: hci3 hci_cmd_timeout RIP: 0010:__rcu_read_lock+0x51/0xb0 kernel/rcu/tree_plugin.h:416 Code: 48 c1 eb 03 42 0f b6 04 33 84 c0 75 35 41 8b 2f ff c5 42 0f b6 04 33 84 c0 75 3e 41 89 2f 42 0f b6 04 33 84 c0 75 49 41 8b 07 <3d> 00 00 00 40 7d 0b 5b 41 5e 41 5f 5d c3 cc cc cc cc 90 0f 0b 90 RSP: 0018:ffffc900000076a0 EFLAGS: 00000246 RAX: 0000000000000001 RBX: 1ffff1100c3ae088 RCX: ffffffff91bf3000 RDX: dffffc0000000000 RSI: ffffffff81a19311 RDI: ffffc900000077a0 RBP: 0000000000000001 R08: 000000000000000a R09: ffffc90000007890 R10: 0000000000000000 R11: ffffffff81ae60f0 R12: ffffc900000077a0 R13: dffffc0000000000 R14: dffffc0000000000 R15: ffff888061d70444 FS: 0000000000000000(0000) GS:ffff888124fa8000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6fdfa9a270 CR3: 0000000063db6000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_read_lock include/linux/rcupdate.h:839 [inline] class_rcu_constructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0xb1/0x23b0 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x11e/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x11a/0x1d0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2398 [inline] slab_free_after_rcu_debug+0x11a/0x280 mm/slub.c:4706 rcu_do_batch kernel/rcu/tree.c:2568 [inline] rcu_core+0xaac/0x17a0 kernel/rcu/tree.c:2824 handle_softirqs+0x2d6/0x9b0 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0xfb/0x220 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2061 [inline] RIP: 0010:vprintk_emit+0x731/0xa40 kernel/printk/printk.c:2449 Code: 00 e8 d3 27 21 00 4c 8d bc 24 a0 00 00 00 4d 85 e4 75 07 e8 c1 27 21 00 eb 06 e8 ba 27 21 00 fb 49 bc 00 00 00 00 00 fc ff df <48> c7 c7 80 9a c1 8e 31 f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 RSP: 0018:ffffc900042777a0 EFLAGS: 00000293 RAX: ffffffff81a19306 RBX: 0000000000000000 RCX: ffff888061d70000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc900042778b0 R08: ffffffff81a192df R09: 1ffffffff20bfbae R10: dffffc0000000000 R11: fffffbfff20bfbaf R12: dffffc0000000000 R13: 1ffff9200084eef8 R14: ffffffff81a19132 R15: ffffc90004277840 _printk+0xd5/0x120 kernel/printk/printk.c:2475 bt_err+0x126/0x180 net/bluetooth/lib.c:296 hci_cmd_timeout+0x104/0x1e0 net/bluetooth/hci_core.c:1457 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xac3/0x18e0 kernel/workqueue.c:3319 worker_thread+0x870/0xd50 kernel/workqueue.c:3400 kthread+0x7b7/0x940 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