Makefiles: Fix _FORTIFY_SOURCE macros #155
Open
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This commit fixes the mistake in the `_FORTIFY_SOURCE` macro where it was not prefixed with underscore while it has to be (see e.g. https://github.com/search?q=repo%3Abminor%2Fglibc%20FORTIFY_SOURCE&type=code). Additionally, to make this macro add extra security, one has to enable optimizations. I am not sure if the build system enables them, but it is worth double checking that as well. Overall, I would recommend using `-D_FORTIFY_SOURCE=3` with `-O2` or `-O3`. (The fortify source level 3 was added recently and you can read more about it here: https://developers.redhat.com/blog/2021/04/16/broadening-compiler-checks-for-buffer-overflows-in-_fortify_source). You can also see the result of the correct vs incorrect macro along with optimizations and no optimizations on this screenshot ([source](https://godbolt.org/#z:OYLghAFBqd5QCxAYwPYBMCmBRdBLAF1QCcAaPECAMzwBtMA7AQwFtMQByARg9KtQYEAysib0QXACx8BBAKoBnTAAUAHpwAMvAFYTStJg1DIApACYAQuYukl9ZATwDKjdAGFUtAK4sGIM6SuADJ4DJgAcj4ARpjEIABspAAOqAqETgwe3r7%2ByanpAiFhkSwxcYl2mA4ZQgRMxARZPn4BldUCtfUERRHRsQm2dQ1NOa1D3aG9pf3xAJS2qF7EyOwc5gDMocjeWADUJutuCgTEocAAdAgH2CYaAIK3d6EEuyxMoRDPu8ik3wj1ACpdvVgAA3EwAVisEIAIrN9gB2Kz3XZ/eq7KJeKiQixcDSQmEHZF3VHHZZJACeEExVF%2BIPBUPxsNmRMeJgRMI481onAhvD8HC0pFQnDc1msuwUi2WmH2ZnWPFIBE0XPmAGsJPFzhD1gAOLgKgCc8TMZmNkkN%2Bk4kn5KuFnF4ChAGiVKvmcFgMCgXogSDQLCSdFi5Eo/sD9DiwC4ptIWFBeBWADU8JgAO4AeSSjE4ipotAIsSd1LtUVC9QpOd4/rYgnTDFoFcFvCwbyM4ibsbwxCqjlBmCdHcwqiqXgLduemB5HdoeCixHLHiwdpOeBYlfmVAMwAUybTmez3F4/EEIjE7CkMkEihU6g7umkBiMKHFln0s6dkHmqCSjgEA4AtDCAD6ABi6YAEoACoAJIgQAmkBQjpnI4FuDc6wwlwuz/umiptL%2BfgQK4Ix%2BFwgQMOgPQlGUegpGkBEkbR%2BQEVRfRxGR%2BE1OMjEcZOPZcV0rHTOxgxdDxokNEJNFcPMUpLCsEjcrytodiKHC7KourxP%2B8SSLswDIMguzRucZi7BAuCECQcoKrMvDKk2szzAgmBMFgcQQOqIAQi6U42qQa7rFqhoaPEXC6VwUi6ZI8TGqQApCmpjrOq6jmkB6iAoKgAZBmQFAQGGuUgFGMZxgmmC7hmWYCrmdAFsQRZRCWZbEI2irVowBB1g2dotoYwDtkK%2BDdtUfYDkKQ4jmOHYTlOQoznOC4YKsQormuh4bluO4plVB65rIp7iBex7yEoah2roEL6P1z6WNYb5RB%2BnnCj%2BGQAcBYFQbBCFIShaEHJh2HpkKnHOERFHicEkzUf0ZF0QUmSeM0TH0RkUmw7YfHtAwnTDEjOS8fYBG4xMxRsXoxxifjpESaTUzSbJ0oKTJVocHy8V2mpGlaTpekGUZJlmRZ%2BBEMQNkyfZbrOa57mUEpHD%2BWuZrnAi8QaD5ZgQhCZgaGYXCGoa6wc6pDq2ClDlaO6Pp%2Btl4bBvlhURsV0YBGVSY7fuNVHnVhaUE1HalswrWVqQHW1vWjZDZgrYDStzZdvxY12pNyCjnH5CCJOdoLfOrWLuna3rnwW2VZ7IcnYd57SCd17nXeAyPsYL42AtT1fq9f6cIBn0wfBiHIah6GAzheFYwRLgQ9TehQ2Twkowj4nwyx0Pk4T/EdNxU9r9jJPoyJlN49kNMH3TMPsYz8nnvL7MJbwXOadpun6YZxlmKZ5mWaL4t2allvy4rIB1jrHOEA0BYDwHG0SqbJ0LoLaqlIBqHyrN1gqSgRwSWaUMpYJtjlCMIYCq2yKiVV2mB4zuz3NVcuPsGp%2B2akHNqVZso1i6hHXq0d%2BqDXjiNXs/Zk7DlTtNIUs1s6zlzhSfOy5TjrR4JtJg25S6UMPJeYQogjrV1kLXW8QpdBkUbrdKwr5W7wHbgRd6oEIK9x%2BgPf6GEzI4TMI6MeGQJ7uC3uRSiK855w2YhkRePjCieOkpjImAlD7I23sTcYe8KabyPjEwSgTYYXxlIpVmN9OacG5o/PmL9BYfxFtZDYEtf7wMQb5a0vBApagRIaMwkhta6nWBoLguotK6kgXfaB5s3TpWtllXB9tQyEKdsQ2MpDyoKL2t7fMvtiwBxagw0OTDOrdUjs2dhbZ07DUTrwwc/C07jkznNXgOclpLg7IXDaxc5HbQoVM5RlcJDqKvGdLROhch6NMHdQx75jEvVMV3D6Fjvr9z%2BkPOxwNHEhLBsRNxM96YYyXr4txSKAmzyCaDHGsTwnBPXlihJ6KMYn3EifaJLM5IpJZlOdJJt1IP15s/AWb8haf0KfKYpcCnKkBcm5foz0/KVP8Lqc4xp4i6hirrLWXAEQQnCh0%2B06CzawJ6dg/pds8pDIGZGF2YyyEVQ9oo2qMyaFzKFIHcsIcw4sJ6h2PqmzeoJ1Grsia%2BzBG8GEdOURZyC5SKLpuG5kyvYPNUVXZRmiLqAOuk%2BL5BiW6/M/P8t6gKe4gt%2BoPAGEKHG4uxi4yGFEyV5FRgIPxRaGAFsxSTElTiN4EoRfvbFBNaZkuScza%2BqDOl0p5k/fmr937CysmLIpP9OXS15R5f%2Bgr1iSFMpIDQCJmlSEkGaPU8qkpKpKVyspyD20KowX/BBIBGnnBii0sVGh1gInnesbWrMs1rjxC6W%2Bu6N3yyzU%2BtdI7SB9gas4yQQA%3D%3D%3D)): 
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This commit fixes the mistake in the
_FORTIFY_SOURCEmacro where it was not prefixed with underscore while it has to be (see e.g. https://github.com/search?q=repo%3Abminor%2Fglibc%20FORTIFY_SOURCE&type=code).Additionally, to make this macro add extra security, one has to enable optimizations. I am not sure if the build system enables them, but it is worth double checking that as well.
Overall, I would recommend using
-D_FORTIFY_SOURCE=3with-O2or-O3. (The fortify source level 3 was added recently and you can read more about it here: https://developers.redhat.com/blog/2021/04/16/broadening-compiler-checks-for-buffer-overflows-in-_fortify_source).You can also see the result of the correct vs incorrect macro along with optimizations and no optimizations on this screenshot (source):