musl: x87 floating-point stack adjustment imbalance

Background

musl is an implementation of the C standard library built on top of the Linux system call API, including interfaces defined in the base language standard, POSIX, and widely agreed-upon extensions.

Description

A flaw in musl libc’s arch-specific math assembly code for i386 was found which can lead to x87 stack overflow in the execution of subsequent math code.

Impact

Impact depends on how the application built against musl libc handles the ABI-violating x87 state.

Workaround

There is no known workaround at this time.

Resolution

All musl users should upgrade to the latest version:

 # emerge --sync
 # emerge --ask --oneshot --verbose ">=sys-libs/musl-1.1.24"