INFO: task syz.7.4575:7618 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.7.4575 state:D stack:26712 pid:7618 tgid:7618 ppid:24501 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7026 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x818/0x1060 kernel/locking/mutex.c:760 nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:593 nfsd_umount+0x48/0xe0 fs/nfsd/nfsctl.c:1347 deactivate_locked_super+0xc1/0x1a0 fs/super.c:473 deactivate_super fs/super.c:506 [inline] deactivate_super+0xde/0x100 fs/super.c:502 put_fs_context+0xac/0x600 fs/fs_context.c:517 fscontext_release+0x47/0x60 fs/fsopen.c:79 __fput+0x402/0xb70 fs/file_table.c:468 task_work_run+0x150/0x240 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xec/0x130 kernel/entry/common.c:43 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x426/0xfa0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f38ddb8f6c9 RSP: 002b:00007ffd21f1ff08 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f38ddde7da0 RCX: 00007f38ddb8f6c9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f38ddde7da0 R08: 000000000000022c R09: 0000001e21f201ff R10: 00007f38ddde7cb0 R11: 0000000000000246 R12: 0000000000153505 R13: 00007ffd21f20000 R14: ffffffffffffffff R15: 00007ffd21f20020 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e3c4720 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e3c4720 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e3c4720 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775 3 locks held by kworker/1:2/1205: #0: ffff88813ff11948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238 #1: ffffc900045bfd00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239 #2: ffff8880878cd240 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x1b6/0x6da0 drivers/net/netdevsim/fib.c:1490 3 locks held by kworker/0:2/1915: #0: ffff88813ff11948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238 #1: ffffc900054a7d00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239 #2: ffff888083954240 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x1b6/0x6da0 drivers/net/netdevsim/fib.c:1490 3 locks held by kworker/u8:6/2907: #0: ffff88813ff29948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238 #1: ffffc9000bf6fd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239 #2: ffffffff900e7408 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0x51/0xc0 net/core/link_watch.c:303 3 locks held by kworker/u8:9/3460: #0: ffff888030ba1948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238 #1: ffffc9000c73fd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239 #2: ffffffff900e7408 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff900e7408 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x120/0x14e0 net/ipv6/addrconf.c:4194 2 locks held by getty/5578: #0: ffff8880357d00a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 3 locks held by kworker/0:1/23935: #0: ffff88813ff11948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238 #1: ffffc900050d7d00 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239 #2: ffffffff900e7408 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 4 locks held by kworker/u8:16/2206: #0: ffff8880b853a398 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:638 #1: ffffffff8e3c4720 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #1: ffffffff8e3c4720 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #1: ffffffff8e3c4720 (rcu_read_lock){....}-{1:3}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2074 [inline] #1: ffffffff8e3c4720 (rcu_read_lock){....}-{1:3}, at: bpf_trace_run4+0x1d5/0x5b0 kernel/trace/bpf_trace.c:2118 #2: ffff888032cb8788 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6358 [inline] #2: ffff888032cb8788 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: cfg80211_wiphy_work+0x99/0x580 net/wireless/core.c:421 #3: ffffffff9ad79508 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0x14c/0x4c0 lib/debugobjects.c:818 2 locks held by syz.0.4230/4748: #0: ffffffff9018b190 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e7ee168 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xd5/0x1b10 fs/nfsd/nfsctl.c:1880 2 locks held by syz.7.4575/7618: #0: ffff888082ff80e0 (&type->s_umount_key#99){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff888082ff80e0 (&type->s_umount_key#99){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff888082ff80e0 (&type->s_umount_key#99){+.+.}-{4:4}, at: deactivate_super fs/super.c:505 [inline] #0: ffff888082ff80e0 (&type->s_umount_key#99){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502 #1: ffffffff8e7ee168 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:593 1 lock held by syz-executor/11056: #0: ffffffff900e7408 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff900e7408 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_newaddr+0x4e4/0x1c70 net/ipv6/addrconf.c:5027 1 lock held by syz-executor/11060: #0: ffffffff900e7408 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff900e7408 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff900e7408 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x600/0x2000 net/core/rtnetlink.c:4064 1 lock held by syz-executor/11066: #0: ffffffff900e7408 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff900e7408 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x371/0xe90 net/core/rtnetlink.c:6957 3 locks held by syz-executor/11076: #0: ffffffff9018b190 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff9018b248 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff9018b248 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff9018b248 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:57 [inline] #1: ffffffff9018b248 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x577/0x800 net/netlink/genetlink.c:1209 #2: ffffffff900e7408 (rtnl_mutex){+.+.}-{4:4}, at: wg_set_device+0xce/0x1320 drivers/net/wireguard/netlink.c:514 2 locks held by syz.7.5052/12898: #0: ffffffff900e7408 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff900e7408 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff900e7408 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x600/0x2000 net/core/rtnetlink.c:4064 #1: ffffffff8e3cfcb8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x284/0x3c0 kernel/rcu/tree_exp.h:311 2 locks held by syz.7.5052/12902: #0: ffffffff9018b190 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff9018b248 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff9018b248 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff9018b248 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:57 [inline] #1: ffffffff9018b248 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x577/0x800 net/netlink/genetlink.c:1209 1 lock held by syz.7.5052/12903: #0: ffffffff900e7408 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff900e7408 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff900e7408 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x600/0x2000 net/core/rtnetlink.c:4064 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline] watchdog+0xf3f/0x1170 kernel/hung_task.c:495 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x675/0x7d0 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: 12898 Comm: syz.7.5052 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:__sanitizer_cov_trace_pc+0x4/0x70 kernel/kcov.c:213 Code: 48 89 df 5b e9 ed 23 5d 00 be 03 00 00 00 5b e9 e2 ba e7 02 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa <48> 8b 34 24 65 48 8b 15 38 97 e4 11 65 8b 05 49 97 e4 11 a9 00 01 RSP: 0018:ffffc9000cfae550 EFLAGS: 00000246 RAX: 0000000000000002 RBX: ffffc9000cfae95a RCX: ffffffff8b5cb8eb RDX: ffff88803b0f2480 RSI: 0000000000000000 RDI: 0000000000000001 RBP: 0000000000000004 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 000000000015ac00 R12: ffffc9000cfae95a R13: 0000000000000000 R14: ffffc9008cfae957 R15: 0000000000000003 FS: 00007f79ef5566c0(0000) GS:ffff888124a08000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f79ec5b2d58 CR3: 0000000074187000 CR4: 00000000003526f0 Call Trace: number+0x6db/0xc70 lib/vsprintf.c:541 vsnprintf+0x5e6/0x1160 lib/vsprintf.c:2890 sprintf+0xcc/0x100 lib/vsprintf.c:3089 print_time kernel/printk/printk.c:1354 [inline] info_print_prefix+0x25a/0x350 kernel/printk/printk.c:1380 record_print_text+0x140/0x400 kernel/printk/printk.c:1429 printk_get_next_message+0x2d1/0x6d0 kernel/printk/printk.c:2997 console_emit_next_record kernel/printk/printk.c:3065 [inline] console_flush_all+0x6ea/0xc60 kernel/printk/printk.c:3199 __console_flush_and_unlock kernel/printk/printk.c:3258 [inline] console_unlock+0xd8/0x210 kernel/printk/printk.c:3298 vprintk_emit+0x3d7/0x680 kernel/printk/printk.c:2423 _printk+0xc7/0x100 kernel/printk/printk.c:2448 batadv_hardif_deactivate_interface net/batman-adv/hard-interface.c:691 [inline] batadv_hardif_deactivate_interface net/batman-adv/hard-interface.c:683 [inline] batadv_hardif_disable_interface+0x18e/0xe70 net/batman-adv/hard-interface.c:822 batadv_meshif_slave_del+0x10e/0x130 net/batman-adv/mesh-interface.c:868 do_set_master+0x172/0x730 net/core/rtnetlink.c:2940 do_setlink.constprop.0+0xbd8/0x4380 net/core/rtnetlink.c:3158 rtnl_group_changelink net/core/rtnetlink.c:3783 [inline] __rtnl_newlink net/core/rtnetlink.c:3937 [inline] rtnl_newlink+0x18e0/0x2000 net/core/rtnetlink.c:4065 rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:6951 netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2552 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x8c8/0xdd0 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0xa98/0xc70 net/socket.c:2630 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2684 __sys_sendmsg+0x16d/0x220 net/socket.c:2716 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f79ee78f6c9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f79ef556038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f79ee9e5fa0 RCX: 00007f79ee78f6c9 RDX: 0000000000000000 RSI: 0000200000000280 RDI: 0000000000000008 RBP: 00007f79ee811f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f79ee9e6038 R14: 00007f79ee9e5fa0 R15: 00007fff78f453c8