CVE ID:	CVE-2022-48769
Description:	In the Linux kernel, the following vulnerability has been resolved: efi: runtime: avoid EFIv2 runtime services on Apple x86 machines Aditya reports [0] that his recent MacbookPro crashes in the firmware when using the variable services at runtime. The culprit appears to be a call to QueryVariableInfo(), which we did not use to call on Apple x86 machines in the past as they only upgraded from EFI v1.10 to EFI v2.40 firmware fairly recently, and QueryVariableInfo() (along with UpdateCapsule() et al) was added in EFI v2.00. The only runtime service introduced in EFI v2.00 that we actually use in Linux is QueryVariableInfo(), as the capsule based ones are optional, generally not used at runtime (all the LVFS/fwupd firmware update infrastructure uses helper EFI programs that invoke capsule update at boot time, not runtime), and not implemented by Apple machines in the first place. QueryVariableInfo() is used to 'safely' set variables, i.e., only when there is enough space. This prevents machines with buggy firmwares from corrupting their NVRAMs when they run out of space. Given that Apple machines have been using EFI v1.10 services only for the longest time (the EFI v2.0 spec was released in 2006, and Linux support for the newly introduced runtime services was added in 2011, but the MacbookPro12,1 released in 2015 still claims to be EFI v1.10 only), let's avoid the EFI v2.0 ones on all Apple x86 machines. [0] https://l ore.kernel.org/all/6D757C75-65B1-468B-842D-10410081A8E4@live.com/
Test IDs:	None available
Cross References:	Common Vulnerability Exposure (CVE) ID: CVE-2022-48769 https://git.kernel.org/stable/c/3df52448978802ae15dcebf66beba1029df957b4 https://git.kernel.org/stable/c/3df52448978802ae15dcebf66beba1029df957b4 https://git.kernel.org/stable/c/a4085859411c825c321c9b55b8a9dc5a128a6684 https://git.kernel.org/stable/c/a4085859411c825c321c9b55b8a9dc5a128a6684 https://git.kernel.org/stable/c/b0f1cc093bc2493ac259c53766fd2b800e085807 https://git.kernel.org/stable/c/b0f1cc093bc2493ac259c53766fd2b800e085807 https://git.kernel.org/stable/c/f5390cd0b43c2e54c7cf5506c7da4a37c5cef746 https://git.kernel.org/stable/c/f5390cd0b43c2e54c7cf5506c7da4a37c5cef746