The ring_buffer_resize function in kernel/trace/ring_buffer.c in the profiling subsystem in the Linux kernel before 4.6.1 mishandles certain integer calculations, which allows local users to gain privileges by writing to the /sys/kernel/debug/tracing/buffer_size_kb file.
https://source.android.com/security/bulletin/2017-01-01.html
https://github.com/torvalds/linux/commit/59643d1535eb220668692a5359de22545af579f6