INFO: task syz.1.7681:1601 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.7681 state:D stack:24872 pid:1601 tgid:1600 ppid:28421 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x15dd/0x52d0 kernel/sched/core.c:6908 __schedule_loop kernel/sched/core.c:6990 [inline] schedule+0x164/0x360 kernel/sched/core.c:7005 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7062 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x7fe/0x1300 kernel/locking/mutex.c:776 nfsd_nl_version_set_doit+0xcd/0x7a0 fs/nfsd/nfsctl.c:1743 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:2550 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x80f/0x9b0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0x972/0x9f0 net/socket.c:2592 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2646 __sys_sendmsg net/socket.c:2678 [inline] __do_sys_sendmsg net/socket.c:2683 [inline] __se_sys_sendmsg net/socket.c:2681 [inline] __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2681 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f63cc99c799 RSP: 002b:00007f63cd7bd028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f63ccc15fa0 RCX: 00007f63cc99c799 RDX: 0000000004008090 RSI: 0000200000000140 RDI: 000000000000000a RBP: 00007f63cca32c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f63ccc16038 R14: 00007f63ccc15fa0 R15: 00007ffeb20e9a18 Showing all locks held in the system: 3 locks held by kworker/1:0/24: #0: ffff88813fe0f148 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline] #0: ffff88813fe0f148 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358 #1: ffffc900001e7c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #1: ffffc900001e7c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358 #2: ffff888045a54240 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x202/0x3d0 drivers/net/netdevsim/fib.c:1490 1 lock held by khungtaskd/31: #0: ffffffff8e75e420 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e75e420 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e75e420 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5582: #0: ffff888035dab0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211 2 locks held by kworker/u8:23/21795: 2 locks held by kworker/u8:87/30547: #0: ffff88813fe4c948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline] #0: ffff88813fe4c948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358 #1: ffff8880b8624588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933 2 locks held by syz.2.7089/32075: #0: ffffffff8fc3ad70 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8ea858a8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x2b5/0x9a0 fs/nfsd/nfsctl.c:1597 2 locks held by syz.1.7681/1601: #0: ffffffff8fc3ad70 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8ea858a8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_version_set_doit+0xcd/0x7a0 fs/nfsd/nfsctl.c:1743 2 locks held by syz.5.9556/8649: #0: ffffffff8fc3ad70 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8ea858a8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_version_set_doit+0xcd/0x7a0 fs/nfsd/nfsctl.c:1743 1 lock held by syz.4.9585/8742: #0: ffffffff8fbccfc8 (rtnl_mutex){+.+.}-{4:4}, at: netdev_wait_allrefs_any net/core/dev.c:11592 [inline] #0: ffffffff8fbccfc8 (rtnl_mutex){+.+.}-{4:4}, at: netdev_run_todo+0x690/0xde0 net/core/dev.c:11712 2 locks held by syz.3.9593/8780: #0: ffffffff8fbccfc8 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff8fbccfc8 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3436 #1: ffffffff8e7646b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #1: ffffffff8e7646b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961 1 lock held by modprobe/8806: ============================================= 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 02/12/2026 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:161 [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:346 [inline] watchdog+0xfd9/0x1030 kernel/hung_task.c:515 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 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: 2302 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:_static_cpu_has arch/x86/include/asm/cpufeature.h:101 [inline] RIP: 0010:__nr_to_section include/linux/mmzone.h:1972 [inline] RIP: 0010:__pfn_to_section include/linux/mmzone.h:2114 [inline] RIP: 0010:lookup_page_ext mm/page_ext.c:255 [inline] RIP: 0010:page_ext_get+0xf6/0x2e0 mm/page_ext.c:532 Code: 8e 48 c1 e8 03 42 80 3c 28 00 74 0c 48 c7 c7 d8 5e 1a 8e e8 dc d0 f3 ff 4c 2b 35 3d 57 de 0b 49 c1 fe 06 4d 89 f7 49 c1 ef 16 ca 01 00 00 e8 00 96 89 ff 41 bc 00 00 04 00 4c 89 ff 4c 89 e6 RSP: 0018:ffffc9000c177320 EFLAGS: 00000246 RAX: 1ffffffff1c34bdb RBX: ffffffff823c06d2 RCX: ffff8880374d5b80 RDX: 0000000000000000 RSI: ffffffff8c27b560 RDI: ffffffff8c27b520 RBP: 0000000000000001 R08: ffffffff823c06d2 R09: ffffffff8e75e420 R10: dffffc0000000000 R11: fffff94000444387 R12: ffffea0002221c00 R13: dffffc0000000000 R14: 0000000000088870 R15: 0000000000000000 FS: 0000555585e90500(0000) GS:ffff888125460000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4a539e92f8 CR3: 0000000078afe000 CR4: 00000000003526f0 Call Trace: __reset_page_owner+0x28/0x1f0 mm/page_owner.c:306 reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1433 [inline] __free_frozen_pages+0xc2b/0xdb0 mm/page_alloc.c:2978 __kasan_populate_vmalloc_do mm/kasan/shadow.c:393 [inline] __kasan_populate_vmalloc+0x1b2/0x1d0 mm/kasan/shadow.c:424 kasan_populate_vmalloc include/linux/kasan.h:580 [inline] alloc_vmap_area+0xd73/0x14b0 mm/vmalloc.c:2129 __get_vm_area_node+0x1f8/0x300 mm/vmalloc.c:3232 __vmalloc_node_range_noprof+0x372/0x1730 mm/vmalloc.c:4024 __vmalloc_node_noprof mm/vmalloc.c:4124 [inline] vzalloc_noprof+0xb2/0xe0 mm/vmalloc.c:4202 alloc_counters+0x64/0x5d0 net/ipv4/netfilter/ip_tables.c:799 copy_entries_to_user net/ipv6/netfilter/ip6_tables.c:837 [inline] get_entries net/ipv6/netfilter/ip6_tables.c:1039 [inline] do_ip6t_get_ctl+0xabd/0x1230 net/ipv6/netfilter/ip6_tables.c:1677 nf_getsockopt+0x26e/0x290 net/netfilter/nf_sockopt.c:116 ipv6_getsockopt+0x1fd/0x2b0 net/ipv6/ipv6_sockglue.c:1473 do_sock_getsockopt+0x2d3/0x3f0 net/socket.c:2383 __sys_getsockopt net/socket.c:2412 [inline] __do_sys_getsockopt net/socket.c:2419 [inline] __se_sys_getsockopt net/socket.c:2416 [inline] __x64_sys_getsockopt+0x1a4/0x240 net/socket.c:2416 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4a5379df6a Code: 48 83 ec 10 89 d2 48 63 ff 45 31 c9 6a 2a 45 31 c0 31 c9 e8 d8 99 fb ff 48 83 c4 18 c3 0f 1f 00 49 89 ca b8 37 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 06 c3 0f 1f 44 00 00 48 c7 c2 e8 ff ff ff f7 RSP: 002b:00007fffa09d50d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000037 RAX: ffffffffffffffda RBX: 00007fffa09d5160 RCX: 00007f4a5379df6a RDX: 0000000000000041 RSI: 0000000000000029 RDI: 0000000000000003 RBP: 0000000000000003 R08: 00007fffa09d50fc R09: 0000000000000000 R10: 00007fffa09d5160 R11: 0000000000000212 R12: 00007f4a539e9900 R13: 00007fffa09d50fc R14: 0000000000000000 R15: 00007f4a539e9fc0