This bug is awaiting verification that the linux- hwe-5.15/5.15.0-32.33~20.04.1 kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-focal' to 'verification-done-focal'. If the problem still exists, change the tag 'verification-needed-focal' to 'verification-failed-focal'.
If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you! ** Tags added: verification-needed-focal -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1967579 Title: harden indirect calls against BHI attacks Status in linux package in Ubuntu: Fix Released Status in linux source package in Jammy: In Progress Bug description: [Impact] Branch History Injection is made easier when all indirect calls are funneled through very few points where the retpolines were. By replacing the retpoline jumps by indirect calls whenever retpolines are disabled, BHI attacks are more difficult to execute as the BTB is not as fixed as before. [Fixes] Though there are fixes that allow retpoline,lfence to be directly replaced in the indirect calls, given that mitigation is not recommended for most of the situations, that hardening is not as important as the one that works for the spectre_v2=off option (the default one for systems with eIBRS). This latter one is present starting with 5.13, but backporting to 5.4 might be a good measure. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1967579/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
