@montagy The change you mention is part of virtualbox since 6.1.26 commit d0c8c1d9763108e99a60822c3441881cf0007e24 (tag: upstream/6.1.26-dfsg) Author: Gianfranco Costamagna <costamagnagianfra...@yahoo.it> Date: Thu Jul 29 11:18:35 2021 +0200
New upstream version 6.1.26-dfsg diff --git a/src/VBox/VMM/VMMR0/VMMR0JmpA-amd64.asm b/src/VBox/VMM/VMMR0/VMMR0JmpA-amd64.asm index 9d3304175..e1ab30b72 100644 --- a/src/VBox/VMM/VMMR0/VMMR0JmpA-amd64.asm +++ b/src/VBox/VMM/VMMR0/VMMR0JmpA-amd64.asm @@ -32,10 +32,17 @@ %define STACK_PADDING 0eeeeeeeeeeeeeeeeh ;; Workaround for linux 4.6 fast/slow syscall stack depth difference. +;; Update: This got worse with linux 5.13 and CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT. +;; The x86 arch_exit_to_user_mode_prepare code limits the offset to 255, +;; while the generic limit is 1023. See bugref:10064 for details. %ifdef VMM_R0_SWITCH_STACK %define STACK_FUZZ_SIZE 0 %else - %define STACK_FUZZ_SIZE 128 + %ifdef RT_OS_LINUX + %define STACK_FUZZ_SIZE 384 + %else + %define STACK_FUZZ_SIZE 128 + %endif %endif So definitely not the issue -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux-hwe-6.8 in Ubuntu. https://bugs.launchpad.net/bugs/2073267 Title: Virtualbox Guru meditation on VM start caused by kernel commit in v6.9-rc4 Status in linux package in Ubuntu: Invalid Status in linux-hwe-6.8 package in Ubuntu: Invalid Status in linux-signed-hwe-5.15 package in Ubuntu: Confirmed Status in virtualbox package in Ubuntu: Confirmed Status in linux source package in Jammy: Fix Committed Status in linux-hwe-6.8 source package in Jammy: Fix Committed Status in linux-signed-hwe-5.15 source package in Jammy: Invalid Status in virtualbox source package in Jammy: New Bug description: BugLink: https://bugs.launchpad.net/bugs/2073267 SRU Justification: [Impact] Commit "randomize_kstack: Improve entropy diffusion" changed the kernel stack for entropy to 1KiB, limiting the thread kernel stack to 15Kib. This impacts virtualbox 6.1.50 on jammy, that is no longer maintained upstream. The issue does not persist on version 7.0.20 due to a code refactoring that probably resulted in less stack usage. Fixing it on the jammy virtualbox package side is not straightfoward because the fix is not easy to backport to 6.x and upgrading the jammy package to 7.x breaks current users machines that run Windows, but not only. Users need to uninstall the Guest additions drivers, migrate the virtualbox package to 7.x, boot each VMs and install the Guest additions drivers in each VM. This impacts: 1. jammy:linux 2. jammy:linux-hwe-6.8 3. focal:linux-hwe-5.15 [Fix] Revert commit "randomize_kstack: Improve entropy diffusion" [Test Plan] Without this fix, a VM would crash, showing with "VCPU0: Guru Meditation -2708 (VERR_VMM_SET_JMP_ABORTED_RESUME)". After the kernel upgrade, all VMs should run with no problem. [Where problems could occur] This may have an impact on security. The commit is a fix to improve the stack entropy. Original description: It worked yesterday, but today I get a Guru Meditation trying to start some of my virtual machines. This shows up in VBox.log as "VCPU0: Guru Meditation -2708 (VERR_VMM_SET_JMP_ABORTED_RESUME)". I suspect this may have started due to a Linux kernel upgrade I installed this morning. A fresh VM with no disk shows the issue. Sometimes turning off the I/O APIC makes the issue go away, sometimes not. Turning off nested paging sometimes lets VirtualBox make a little bit of progress w.r.t. booting VMs, but that usually still crashes before the VM finishes starting. This may be related to this bug reported on the VirtualBox forums: https://forums.virtualbox.org/viewtopic.php?t=111889&sid=5cd33c0872a03b689e7e9f84d850f538 https://forums.virtualbox.org/viewtopic.php?t=111918 Ubuntu is 22.04.4 LTS, kernel is 5.15.0-116-generic, VirtualBox is 6.1.50-dfsg-1~ubuntu1.22.04.1. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2073267/+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