INFO: task syz.3.3505:17203 blocked for more than 143 seconds. Not tainted 6.16.0-rc2-syzkaller-00024-g9afe652958c3 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.3505 state:D stack:25352 pid:17203 tgid:17202 ppid:13352 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0x165/0x360 kernel/sched/core.c:6878 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6935 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x724/0xe80 kernel/locking/mutex.c:747 nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:596 nfsd_umount+0x42/0xd0 fs/nfsd/nfsctl.c:1386 deactivate_locked_super+0xbc/0x130 fs/super.c:474 put_fs_context+0x93/0x790 fs/fs_context.c:520 fscontext_release+0x62/0x80 fs/fsopen.c:73 __fput+0x449/0xa70 fs/file_table.c:465 task_work_run+0x1d1/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:114 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb0c178e929 RSP: 002b:00007fb0c2537038 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007fb0c19b5fa0 RCX: 00007fb0c178e929 RDX: 0000000000000000 RSI: ffffffffffffffff RDI: 0000000000000004 RBP: 00007fb0c1810b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fb0c19b5fa0 R15: 00007ffd8a29c708 Showing all locks held in the system: 8 locks held by kworker/u8:0/12: #0: ffff88801b2fb948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801b2fb948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321 #1: ffffc90000117bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] ffffc90000117bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321 #2: ffffffff8f4f1410 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800 net/core/net_namespace.c:662 #3: ffff888021ad90e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline] #3: ffff888021ad90e8 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline] #3: ffff888021ad90e8 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x10a/0x3d0 net/devlink/core.c:506 #4: ffff8880550a8250 (&devlink->lock_key#12){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:276 [inline] #4: ffff8880550a8250 (&devlink->lock_key#12){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:109 [inline] #4: ffff8880550a8250 (&devlink->lock_key#12){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x11c/0x3d0 net/devlink/core.c:506 #5: ffffffff8f4fe008 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0xdb/0x670 drivers/net/netdevsim/netdev.c:1064 #6: ffffffff8e1448b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline] #6: ffffffff8e1448b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:998 #7: ffff8880b863b798 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:606 3 locks held by kworker/u8:1/13: #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321 #1: ffffc90000127bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90000127bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321 #2: ffffffff8f4fe008 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 1 lock held by khungtaskd/31: #0: ffffffff8e13eda0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13eda0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e13eda0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770 3 locks held by kworker/1:1/48: 2 locks held by kworker/u8:3/49: 2 locks held by kworker/1:2/977: 2 locks held by getty/5589: #0: ffff88803418a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900036bb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 2 locks held by kworker/1:3/5834: 4 locks held by kworker/1:4/5891: 3 locks held by kworker/1:5/5912: 2 locks held by syz.4.2414/14661: #0: ffffffff8f5641b0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e41b488 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x12a/0x1650 fs/nfsd/nfsctl.c:1923 1 lock held by syz.5.2642/15171: #0: ffffffff8f4fe008 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:633 [inline] #0: ffffffff8f4fe008 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3396 2 locks held by syz.3.3505/17203: #0: ffff88807b4020e0 (&type->s_umount_key#86){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff88807b4020e0 (&type->s_umount_key#86){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff88807b4020e0 (&type->s_umount_key#86){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 #1: ffffffff8e41b488 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:596 1 lock held by syz.7.3985/18308: #0: ffffffff8f4fe008 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:633 [inline] #0: ffffffff8f4fe008 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3396 3 locks held by kworker/1:7/20531: 4 locks held by kworker/1:8/20537: 2 locks held by syz.6.4926/20546: #0: ffffffff8f4f1410 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0 net/core/net_namespace.c:570 #1: ffffffff8f4fe008 (rtnl_mutex){+.+.}-{4:4}, at: wg_netns_pre_exit+0x1c/0x1d0 drivers/net/wireguard/device.c:417 1 lock held by syz.0.4929/20554: #0: ffffffff8f4fe008 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:633 [inline] #0: ffffffff8f4fe008 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3396 1 lock held by syz-executor/20572: #0: ffffffff8f4fe008 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f4fe008 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0 net/ipv4/devinet.c:979 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc2-syzkaller-00024-g9afe652958c3 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline] watchdog+0xfee/0x1030 kernel/hung_task.c:470 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 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: 5912 Comm: kworker/1:5 Not tainted 6.16.0-rc2-syzkaller-00024-g9afe652958c3 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: wg-kex-wg2 wg_packet_handshake_receive_worker RIP: 0010:__asan_memset+0x22/0x50 mm/kasan/shadow.c:84 Code: 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 41 56 53 48 89 d3 89 f5 49 89 fe 48 8b 4c 24 18 48 89 d6 ba 01 00 00 00 e8 7e e4 ff ff <84> c0 74 11 4c 89 f7 89 ee 48 89 da 5b 41 5e 5d e9 09 ab 3d 09 31 RSP: 0000:ffffc90000a07c58 EFLAGS: 00000256 RAX: 1ffff92000140f01 RBX: 0000000000000010 RCX: ffffffff8172a6e8 RDX: 0000000000000001 RSI: 0000000000000010 RDI: ffffc90000a07d98 RBP: 0000000000000000 R08: ffffc90000a07da7 R09: 1ffff92000140fb4 R10: dffffc0000000000 R11: fffff52000140fb5 R12: ffffc90000a086e0 R13: ffffc90000a07d98 R14: ffffc90000a07d98 R15: ffffc90000a07d90 FS: 0000000000000000(0000) GS:ffff888125d85000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2ea0dff8 CR3: 000000000df38000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: unwind_next_frame+0xc98/0x2390 arch/x86/kernel/unwind_orc.c:592 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4148 [inline] slab_alloc_node mm/slub.c:4197 [inline] kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4204 skb_clone+0x212/0x3a0 net/core/skbuff.c:2050 deliver_clone net/bridge/br_forward.c:125 [inline] maybe_deliver+0x98/0x160 net/bridge/br_forward.c:190 br_flood+0x31a/0x6a0 net/bridge/br_forward.c:237 br_handle_frame_finish+0x14b4/0x19b0 net/bridge/br_input.c:221 br_nf_hook_thresh+0x3c6/0x4a0 net/bridge/br_netfilter_hooks.c:-1 br_nf_pre_routing_finish_ipv6+0x948/0xd00 net/bridge/br_netfilter_ipv6.c:-1 NF_HOOK include/linux/netfilter.h:317 [inline] br_nf_pre_routing_ipv6+0x37e/0x6b0 net/bridge/br_netfilter_ipv6.c:184 nf_hook_entry_hookfn include/linux/netfilter.h:157 [inline] nf_hook_bridge_pre net/bridge/br_input.c:283 [inline] br_handle_frame+0x982/0x14c0 net/bridge/br_input.c:434 __netif_receive_skb_core+0x10de/0x4180 net/core/dev.c:5863 __netif_receive_skb_one_core net/core/dev.c:5975 [inline] __netif_receive_skb+0x72/0x380 net/core/dev.c:6090 process_backlog+0x60e/0x14f0 net/core/dev.c:6442 __napi_poll+0xc7/0x480 net/core/dev.c:7414 napi_poll net/core/dev.c:7478 [inline] net_rx_action+0x707/0xe30 net/core/dev.c:7605 handle_softirqs+0x286/0x870 kernel/softirq.c:579 do_softirq+0xec/0x180 kernel/softirq.c:480 __local_bh_enable_ip+0x17d/0x1c0 kernel/softirq.c:407 local_bh_enable include/linux/bottom_half.h:33 [inline] fpregs_unlock arch/x86/include/asm/fpu/api.h:77 [inline] kernel_fpu_end+0xd2/0x120 arch/x86/kernel/fpu/core.c:476 blake2s_compress+0x5f/0xd0 arch/x86/lib/crypto/blake2s-glue.c:46 blake2s_final+0x116/0x260 lib/crypto/blake2s.c:54 hmac+0x293/0x330 drivers/net/wireguard/noise.c:333 kdf+0x105/0x270 drivers/net/wireguard/noise.c:367 mix_precomputed_dh drivers/net/wireguard/noise.c:426 [inline] wg_noise_handshake_consume_initiation+0x3ee/0x900 drivers/net/wireguard/noise.c:623 wg_receive_handshake_packet drivers/net/wireguard/receive.c:144 [inline] wg_packet_handshake_receive_worker+0x5f2/0xfb0 drivers/net/wireguard/receive.c:213 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245