The ipxitf_ioctl function in net/ipx/af_ipx.c in the Linux kernel through 4.11.1 mishandles reference counts, which allows local users to cause a denial of service (use-after-free) or possibly have unspecified other impact via a failed SIOCGIFADDR ioctl call for an IPX interface.
https://source.android.com/security/bulletin/2017-09-01
https://patchwork.ozlabs.org/patch/757549/
https://github.com/torvalds/linux/commit/ee0d8d8482345ff97a75a7d747efc309f13b0d80
https://bugzilla.redhat.com/show_bug.cgi?id=1447734
http://www.securitytracker.com/id/1039237
http://www.securityfocus.com/bid/98439