The ioresources_init function in kernel/resource.c in the Linux kernel through 4.7, as used in Android before 2016-08-05 on Nexus 6 and 7 (2013) devices, uses weak permissions for /proc/iomem, which allows local users to obtain sensitive information by reading this file, aka Android internal bug 28814213 and Qualcomm internal bug CR786116. NOTE: the permissions may be intentional in most non-Android contexts.