An address corruption flaw was discovered in the Linux kernel built with hardware breakpoint (CONFIGHAVEHWBREAKPOINT) support. While modifying a h/w breakpoint via 'modifyuserhwbreakpoint' routine, an unprivileged user/process could use this flaw to crash the system kernel resulting in DoS OR to potentially escalate privileges on a the system.

A flaw was found in the way the Linux kernel loaded ELF executables. Provided that an application was built as Position Independent Executable (PIE), the loader could allow part of that application's data segment to map over the memory area reserved for its stack, potentially resulting in memory corruption. An unprivileged local user with access to SUID (or otherwise privileged) PIE binary could use this flaw to escalate their privileges on the system.

Upstream patch:

https://git.kernel.org/linus/a87938b2e246b81b4fb713edb371a9fa3c5c3c86