On Mon, May 8, 2017 at 8:22 AM, Daniel Micay <danielmicay@xxxxxxxxx> wrote: > On Mon, 2017-05-08 at 09:52 +0200, Ingo Molnar wrote: >> >> ... it's just not usable in that form for a regular maintenance flow. >> >> So what would be more useful is to add a specific Sparse check that >> only checks >> KERNEL_DS, to add it as a regular (.config driven) build option and >> make sure the >> kernel build has zero warnings. >> >> From that point on we can declare that this kind of bug won't occur >> anymore, if >> the Sparse implementation of the check is correct. >> >> But there's a (big) problem with that development model: Sparse is not >> part of the >> kernel tree and adding a feature to it while making the kernel depend >> on that >> brand new feature is a logistical nightmare. The overhead is quite >> similar to >> adding new features to a compiler - it happens at a glacial pace and >> is only done >> for major features really, at considerable expense. I don't think this >> is an >> adequate model for 'extended syntax checking' of the kernel, >> especially when it >> comes to correctness that has such obvious security impact. >> >> Thanks, >> >> Ingo > > There's the option of using GCC plugins now that the infrastructure was > upstreamed from grsecurity. It can be used as part of the regular build > process and as long as the analysis is pretty simple it shouldn't hurt > compile time much. Well, and that the situation may arise due to memory corruption, not from poorly-matched set_fs() calls, which static analysis won't help solve. We need to catch this bad kernel state because it is a very bad state to run in. -Kees -- Kees Cook Pixel Security -- To unsubscribe from this list: send the line "unsubscribe linux-s390" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
