Hey folks! So, with the latest set of GRUB CVE patches we've fixed up a bunch of potential crashes in font-handling code that could lead to Secure Boot holes. These are good and useful fixes, and thanks to Zhang Boyang and everyone else involved!
There were also a few other changes: * In SB mode, refuse to load fonts from outside of the signed GRUB image * Restrictions to image dimensions * Fix integer overflow in fbutil Locking down fonts here has caused some issues that I've seen. We didn't update the config generation code in util/grub.d, so we're still generating grub.cfg files that will try (and fail!) to load fonts from other locations at runtime in SB mode. This causes ugly errors, and also causes GRUB to fail to set up video as normal. We can fix this, but it would be nice to agree on something upstream rather than as diverging distro patches. AFAIK Chris Coulson has a patch for the font loader to cause it to try loading fonts from the embedded memdisk first. Is that the best approach? If so, what fonts should we be embedding in the signed image? It's a tradeoff between size and functionality, of course - some people are happy with just "unicode" while others may want a wider choice for added theming options. Is the size an issue for most people? Or... Could/should we look at options to sign fonts separately? I've heard suggestions to embed them into faked-up modules that we could load with insmod, but of course we don't support signing modules yet anyway... :-) Thoughts?? -- Steve McIntyre, Cambridge, UK. st...@einval.com "I used to be the first kid on the block wanting a cranial implant, now I want to be the first with a cranial firewall. " -- Charlie Stross _______________________________________________ Grub-devel mailing list Grub-devel@gnu.org https://lists.gnu.org/mailman/listinfo/grub-devel