Nvidia filed bug 6924256 for the Firefox crash, but cannot reproduce the DirectX 12 half
Nvidia has filed bug 6924256 for a crash inside its own EGL library that takes Firefox down under Wayland, but it has not reproduced the DirectX 12 half of the same bug report. An Nvidia moderator posted both verdicts on October 14 in the company's own 615 release feedback thread, writing that the Wayland crash reproduced and "bug 6924256 have been filed for tracking purpose".
The Blood of Dawnwalker is the Unreal Engine 5 title named in the DirectX 12 half of the report, which Nvidia says it still cannot reproduce. Image: Rebel Wolves Image: Rebel Wolves
This is not an Xid 109 bug. The four Xid 109 tracking bugs Nvidia filed through early October all cover GPU-level hangs, while this one is a null-pointer dereference in Nvidia's own userspace EGL library.
The report went up on September 20 and says applications using hardware-accelerated EGL rendering "consistently crash inside libnvidia-eglcore.so.615.71.09 due to a null-pointer dereference", with Firefox 156.0 on WebRender and WebGL as the example. The crash is a SIGSEGV at address 0xc, with the top two stack frames inside Nvidia's EGL library and the third inside Firefox's own libxul.
Disabling hardware acceleration or running through XWayland stops it, the reporter says, which leaves the native Wayland path as the difference. The machine is a GeForce RTX 3070 on Fedora Linux 44 with KDE Plasma, kernel 7.2.5 and driver 615.71.09.
Nvidia asks how often the DirectX 12 failure happens
The other half of the report says newer Unreal Engine 5 DirectX 12 titles fail to create a Vulkan device under Proton and vkd3d-proton, returning VK_ERROR_INITIALIZATION_FAILED, with The Blood of Dawnwalker named as the game. Nvidia says it cannot make that happen: "I am still not able to repro VKD3D-Proton vkCreateDevice Failure (vr -3) in DirectX 12 / UE5."
Nvidia's moderator asked how often it happens, whether the crash lands immediately after launch or intermittently, and for the game's video and display settings. A bug number exists for the Firefox crash and no equivalent exists for this one.
One flag in the posted workaround is not in vkd3d-proton
The report offers a launch option that gets the game running, setting VKD3D_CONFIG to no_subgroups and single_queue together with VKD3D_FEATURE_LEVEL=12_0. vkd3d-proton's own README documents single_queue as "Do not use asynchronous compute or transfer queues", and no_subgroups appears nowhere in it. Another user in the thread said the same thing on the day the report was posted.
The reporter adds that capping the feature level to 12_0 and switching subgroups off makes the DLSS capability check fail, so DLSS is locked out of the game's settings while the workaround is in place. That is the trade on offer for a game that otherwise does not start.
The branch has moved on since the report
Nvidia's newest Linux driver for x86_64 is 615.78.08, with 615.71.09 behind it and 610.57.04 as the previous branch, according to Nvidia's own archive listing. That is the build that switched the driver to the kernel call Nvidia's own engineer said reviewers had objected to, and the report here was filed against 615.71.09.
A filed bug is a tracking entry rather than a fix, and 6924256 covers only the half Nvidia could make happen on its own machines.
