From bc0c48414eaba9e974e54aa8ef611b78037fd387 Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Fri, 23 Oct 2015 00:01:01 -0400 Subject: prevent user CFLAGS overrides from exposing executable stack the option to suppress executable stack tagging was placed in CFLAGS, which is treated as optional and overridable by the build system. if a user replaces CFLAGS after configure has run, it could get lost, resulting in a libc.so that's flagged as needing executable stack, which would cause the kernel to map the initial stack as executable. move -Wa,--noexecstack to CFLAGS_C99FSE, the make variable used for mandatory compiler options. --- configure | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) (limited to 'configure') diff --git a/configure b/configure index 03c0ebe0..742ca261 100755 --- a/configure +++ b/configure @@ -329,6 +329,13 @@ printf "yes\n" CFLAGS_C99FSE="$CFLAGS_C99FSE -D__may_alias__=" fi +# +# The GNU toolchain defaults to assuming unmarked files need an +# executable stack, potentially exposing vulnerabilities in programs +# linked with such object files. Fix this. +# +tryflag CFLAGS_C99FSE -Wa,--noexecstack + # # Check for options to disable stack protector, which needs to be # disabled for a few early-bootstrap translation units. If not found, @@ -429,13 +436,6 @@ fi tryflag CFLAGS_AUTO -fno-unwind-tables tryflag CFLAGS_AUTO -fno-asynchronous-unwind-tables -# -# The GNU toolchain defaults to assuming unmarked files need an -# executable stack, potentially exposing vulnerabilities in programs -# linked with such object files. Fix this. -# -tryflag CFLAGS_AUTO -Wa,--noexecstack - # # On x86, make sure we don't have incompatible instruction set # extensions enabled by default. This is bad for making static binaries. -- cgit v1.2.1