[Bug]: In GNU/Linux guests using kernel 6.17 and X11, the mouse pointer appears offset down and right

[roadSurfer]

Version

7.2.6

Host OS Type

Windows

Host OS name + version

Windows 11 Build 26100

Host Architecture

x86

Guest OS Type

Linux

Guest Architecture

x86

Guest OS name + version

Kde Neon (based on Ubuntu 24.04)

Component

Other

What happened?

In a KDE Neon when using kernel 6.17 and X11, when over a window the mouse pointer appears to be offset down by one line and to the right by two characters. Switching to Wayland or to kernel 6.14 resolves the issue.

I tried multiple other solutions, all of which failed to alter the behaviour:

• 3D acceleration on/off
• Compositing on/off
• XOrg transformations
• Mouse type USB Tablet/PS2
• Mouse integation on/off
• libinput bs evdev

The desktop does not seem to exhibit the offset behaviour, only windows.

My chosen workaround is kernel 6.14 as applications I require do not support Wayland at this time.

Could this be related to #464 ?

VBox.log
VBoxHardening.log

How can we reproduce this?

1. Install KDE Neon and run updates (although I am reasonably sure than any GNU/Linux gurst OS using X11 and kernel 6.17 will show the befaviour)
2. Enable mouse integration
3. Install guest addtions
4. Log into an X11 session

Test 1 - Text selection

1. Open a file in "Kate" (or any other GUI editior)
2. Select some text
3. Observe how the selection is one line above and a couple of characters to the left of the pointer

Test 2 - Window border

1. Ensure the window is not maximised and that the top edge is over the desktop with no other window below
2. Slowly move the mouse pointer up and over the window's top edge
3. Observe how there is a small "jump" up and to the left when it crosses on to the desktop
4. Now slowly move the pointer back down over the window
5. Observe how there is a small "jump" down and to the reight when it crosses into the window

Test 3 - Guest edge

1. Move the window to the left of the guest, ensuring that it overlaps the edge and that there is alsw clear desktop above or below
2. Whilst on the window, slowly move the mouse pointer left to the guest edge
3. Observe that the pointer "exits" the guest before it fullt reached the edge
4. Repeat the same test whilst over the desktop
5. Observe that the pointer reaches the edge before it "exits" the guest

Did you upload all of your necessary log files, screenshots, etc.?

• Yes, I've uploaded all pertinent files to this issue.