INFO: task syz.2.6084:29480 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.6084 state:D stack:27168 pid:29480 tgid:29479 ppid:18005 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1821/0x5740 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0x164/0x360 kernel/sched/core.c:7283 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7340 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0x7f7/0x1550 kernel/locking/mutex.c:820 nfsd_nl_listener_get_doit+0x10a/0x610 fs/nfsd/nfsctl.c:2088 genl_family_rcv_msg_doit+0x22a/0x330 net/netlink/genetlink.c:1114 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline] genl_rcv_msg+0x61c/0x7a0 net/netlink/genetlink.c:1209 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2551 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x75c/0x8e0 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1895 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] ____sys_sendmsg+0x972/0x9f0 net/socket.c:2698 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2752 __sys_sendmsg net/socket.c:2784 [inline] __do_sys_sendmsg net/socket.c:2789 [inline] __se_sys_sendmsg net/socket.c:2787 [inline] __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2787 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: 0033:0x7ff5dad9ce59 RSP: 002b:00007ff5dbcb1028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007ff5db015fa0 RCX: 00007ff5dad9ce59 RDX: 0000000004000000 RSI: 0000200000000100 RDI: 0000000000000005 RBP: 00007ff5dae32d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff5db016038 R14: 00007ff5db015fa0 R15: 00007fffbeb6d9e8 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e95cda0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e95cda0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8e95cda0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5385: #0: ffff888031cc90a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0 drivers/tty/n_tty.c:2211 4 locks held by kworker/u8:49/14880: #0: ffff88801be8e140 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline] #0: ffff88801be8e140 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397 #1: ffffc90006557c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline] #1: ffffc90006557c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397 #2: ffffffff8fdc2568 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:673 #3: ffffffff8e962f78 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3828 4 locks held by kworker/1:12/19204: #0: ffff88801aeb2d40 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline] #0: ffff88801aeb2d40 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397 #1: ffffc90003adfc40 ((work_completion)(&(&ssp->srcu_sup->work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline] #1: ffffc90003adfc40 ((work_completion)(&(&ssp->srcu_sup->work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397 #2: ffffffff8e95dc88 (&ssp->srcu_sup->srcu_gp_mutex){+.+.}-{4:4}, at: srcu_advance_state kernel/rcu/srcutree.c:1813 [inline] #2: ffffffff8e95dc88 (&ssp->srcu_sup->srcu_gp_mutex){+.+.}-{4:4}, at: process_srcu+0x6e/0x1630 kernel/rcu/srcutree.c:1973 #3: ffffffff8e9630a8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #3: ffffffff8e9630a8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961 2 locks held by syz.4.5925/28811: #0: ffffffff8fe41548 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8ec8ace0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x141/0x1670 fs/nfsd/nfsctl.c:1938 2 locks held by syz.2.6084/29480: #0: ffffffff8fe41548 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8ec8ace0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_get_doit+0x10a/0x610 fs/nfsd/nfsctl.c:2088 2 locks held by syz.6.7022/684: #0: ffffffff8fe41548 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8ec8ace0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x141/0x1670 fs/nfsd/nfsctl.c:1938 1 lock held by syz.8.7148/1182: #0: ffffffff8fdd1280 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:641 [inline] #0: ffffffff8fdd1280 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3502 1 lock held by syz-executor/1208: #0: ffffffff8fdc2568 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:575 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 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+0x389/0x470 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30531 Comm: kworker/0:5 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Workqueue: events drain_vmap_area_work RIP: 0010:gfpflags_allow_spinning lib/stackdepot.c:645 [inline] RIP: 0010:stack_depot_save_flags+0x5/0x810 lib/stackdepot.c:651 Code: c7 c7 50 a7 12 8f 48 89 da e8 87 9c 00 00 eb d9 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 <41> 57 41 56 41 55 41 54 53 48 83 ec 20 f7 c2 00 0c 00 00 0f 95 c3 RSP: 0018:ffffc9000d38f570 EFLAGS: 00000246 RAX: 000000000000000c RBX: ffff8880a83085f0 RCX: 0000000000000001 RDX: 0000000000002000 RSI: 000000000000000c RDI: ffffc9000d38f5c0 RBP: ffffc9000d38f6b0 R08: 000000000000001e R09: ffffffff8e95cda0 R10: ffffc9000d38f498 R11: ffffffff81b0efc0 R12: dffffc0000000000 R13: 1ffff110150610be R14: ffffc9000d38f5c0 R15: 1ffff92001a71eb4 FS: 0000000000000000(0000) GS:ffff88812527a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffefe3e7f2c CR3: 0000000034ebe000 CR4: 00000000003526f0 Call Trace: save_stack+0x130/0x230 mm/page_owner.c:166 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1402 [inline] __free_frozen_pages+0xbc7/0xd30 mm/page_alloc.c:2943 kasan_depopulate_vmalloc_pte+0x6d/0x90 mm/kasan/shadow.c:484 apply_to_pte_range mm/memory.c:3322 [inline] apply_to_pmd_range mm/memory.c:3366 [inline] apply_to_pud_range mm/memory.c:3402 [inline] apply_to_p4d_range mm/memory.c:3438 [inline] __apply_to_page_range+0xbdc/0x1420 mm/memory.c:3474 __kasan_release_vmalloc+0xa2/0xd0 mm/kasan/shadow.c:602 kasan_release_vmalloc include/linux/kasan.h:593 [inline] kasan_release_vmalloc_node mm/vmalloc.c:2284 [inline] purge_vmap_node+0x220/0x960 mm/vmalloc.c:2306 __purge_vmap_area_lazy+0x779/0xb40 mm/vmalloc.c:2396 drain_vmap_area_work+0x27/0x40 mm/vmalloc.c:2430 process_one_work kernel/workqueue.c:3314 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478 kthread+0x389/0x470 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