e list of known hosts.
executing program
BUG: memory leak
unreferenced object 0xffff888109640900 (size 256):
  comm "softirq", pid 0, jiffies 4294941913 (age 7.710s)
  hex dump (first 32 bytes):
    00 01 00 00 00 00 ad de 00 02 00 00 00 00 ad de  ................
    00 50 bb 1f 81 88 ff ff 00 00 00 00 00 00 00 00  .P..............
  backtrace:
    [<00000000c9542ecf>] kmemleak_alloc_recursive include/linux/kmemleak.h:55 [inline]
    [<00000000c9542ecf>] slab_post_alloc_hook mm/slab.h:439 [inline]
    [<00000000c9542ecf>] slab_alloc mm/slab.c:3326 [inline]
    [<00000000c9542ecf>] kmem_cache_alloc_trace+0x13d/0x280 mm/slab.c:3553
    [<0000000029b9785c>] kmalloc include/linux/slab.h:547 [inline]
    [<0000000029b9785c>] kzalloc include/linux/slab.h:742 [inline]
    [<0000000029b9785c>] lapb_create_cb net/lapb/lapb_iface.c:116 [inline]
    [<0000000029b9785c>] lapb_register+0x90/0x1c0 net/lapb/lapb_iface.c:153
    [<000000002da72f7f>] x25_asy_open drivers/net/wan/x25_asy.c:483 [inline]
    [<000000002da72f7f>] x25_asy_open_tty+0x26b/0x2f6 drivers/net/wan/x25_asy.c:573
    [<00000000c8029036>] tty_ldisc_open.isra.0+0x40/0x70 drivers/tty/tty_ldisc.c:469
    [<000000003cd9b885>] tty_set_ldisc+0x149/0x240 drivers/tty/tty_ldisc.c:596
    [<0000000045822b05>] tiocsetd drivers/tty/tty_io.c:2332 [inline]
    [<0000000045822b05>] tty_ioctl+0x366/0xa30 drivers/tty/tty_io.c:2592
    [<0000000077bdd342>] vfs_ioctl fs/ioctl.c:46 [inline]
    [<0000000077bdd342>] file_ioctl fs/ioctl.c:509 [inline]
    [<0000000077bdd342>] do_vfs_ioctl+0x62a/0x810 fs/ioctl.c:696
    [<0000000039fa62ef>] ksys_ioctl+0x86/0xb0 fs/ioctl.c:713
    [<000000004705e38b>] __do_sys_ioctl fs/ioctl.c:720 [inline]
    [<000000004705e38b>] __se_sys_ioctl fs/ioctl.c:718 [inline]
    [<000000004705e38b>] __x64_sys_ioctl+0x1e/0x30 fs/ioctl.c:718
    [<000000008e00b7e2>] do_syscall_64+0x76/0x1a0 arch/x86/entry/common.c:301
    [<00000000d016c022>] entry_SYSCALL_64_after_hwframe+0x44/0xa9