gentoo-overlay/metadata/news/2014-06-15-gcc48_ssp/2014-06-15-gcc48_ssp.en.txt

Title: GCC 4.8.3 defaults to -fstack-protector
Author: Ryan Hill <rhill@gentoo.org>
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Posted: 2014-06-15
Revision: 2
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Beginning with GCC 4.8.3, Stack Smashing Protection (SSP) will be
enabled by default.  The 4.8 series will enable -fstack-protector
while 4.9 and later enable -fstack-protector-strong.

SSP is a security feature that attempts to mitigate stack-based buffer
overflows by placing a canary value on the stack after the function
return pointer and checking for that value before the function returns.
If a buffer overflow occurs and the canary value is overwritten, the
program aborts.

There is a small performance cost to these features.  They can be
disabled with -fno-stack-protector.

For more information these options, refer to the GCC Manual, or the
following articles.

http://en.wikipedia.org/wiki/Buffer_overflow_protection
http://en.wikipedia.org/wiki/Stack_buffer_overflow
https://securityblog.redhat.com/tag/stack-protector
http://www.outflux.net/blog/archives/2014/01/27/fstack-protector-strong