Public bug reported: [Impact] On dual GFX systems, if amdgpu fails to probe a device, vgaarb for another GFX triggers a NULL pointer dereference and freeze the system.
[Fix] Defer VGA client registering so resources are handled properly when amdgpu probe fails. [Test] With the patch applied, no more kernel panic when vgaarb is changing the VGA mode. [Where problems could occur] VGA clients won't take effect until a successful probe, so unless there is very subtle bug in vgaarb or vgaswitcheroo, it's very unlikely to introduce any regression. ** Affects: hwe-next Importance: Undecided Status: New ** Affects: linux (Ubuntu) Importance: Critical Status: Confirmed ** Affects: linux-oem-5.10 (Ubuntu) Importance: Undecided Status: Invalid ** Affects: linux (Ubuntu Focal) Importance: Undecided Status: Won't Fix ** Affects: linux-oem-5.10 (Ubuntu Focal) Importance: Critical Status: Confirmed ** Affects: linux (Ubuntu Hirsute) Importance: Critical Status: Confirmed ** Affects: linux-oem-5.10 (Ubuntu Hirsute) Importance: Undecided Status: Invalid ** Tags: oem-priority originate-from-1914566 stella ** Also affects: linux-oem-5.10 (Ubuntu) Importance: Undecided Status: New ** Also affects: linux (Ubuntu Focal) Importance: Undecided Status: New ** Also affects: linux-oem-5.10 (Ubuntu Focal) Importance: Undecided Status: New ** Also affects: linux (Ubuntu Hirsute) Importance: Undecided Status: New ** Also affects: linux-oem-5.10 (Ubuntu Hirsute) Importance: Undecided Status: New ** Changed in: linux-oem-5.10 (Ubuntu Hirsute) Status: New => Invalid ** Changed in: linux-oem-5.10 (Ubuntu) Status: New => Invalid ** Changed in: linux (Ubuntu Focal) Status: New => Won't Fix ** Changed in: linux (Ubuntu) Status: New => Confirmed ** Changed in: linux (Ubuntu Hirsute) Status: New => Confirmed ** Changed in: linux-oem-5.10 (Ubuntu Focal) Status: New => Confirmed ** Changed in: linux (Ubuntu) Importance: Undecided => Critical ** Changed in: linux (Ubuntu Hirsute) Importance: Undecided => Critical ** Changed in: linux-oem-5.10 (Ubuntu Focal) Importance: Undecided => Critical ** Tags added: oem-priority originate-from-1914566 stella -- 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/1926792 Title: Fix kernel panic at boot on dual GFX systems Status in HWE Next: New Status in linux package in Ubuntu: Confirmed Status in linux-oem-5.10 package in Ubuntu: Invalid Status in linux source package in Focal: Won't Fix Status in linux-oem-5.10 source package in Focal: Confirmed Status in linux source package in Hirsute: Confirmed Status in linux-oem-5.10 source package in Hirsute: Invalid Bug description: [Impact] On dual GFX systems, if amdgpu fails to probe a device, vgaarb for another GFX triggers a NULL pointer dereference and freeze the system. [Fix] Defer VGA client registering so resources are handled properly when amdgpu probe fails. [Test] With the patch applied, no more kernel panic when vgaarb is changing the VGA mode. [Where problems could occur] VGA clients won't take effect until a successful probe, so unless there is very subtle bug in vgaarb or vgaswitcheroo, it's very unlikely to introduce any regression. To manage notifications about this bug go to: https://bugs.launchpad.net/hwe-next/+bug/1926792/+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