Off-by-one error in CORE/HDD/src/wlan_hdd_hostapd.c in the Qualcomm Wi-Fi driver in Android before 2016-10-05 on Nexus 5X and Android One devices allows attackers to gain privileges or cause a denial of service (buffer overflow) via a crafted application that makes a linkspeed ioctl call, aka Android internal bug 30873776 and Qualcomm internal bug CR 1000861.