** Description changed: - Last time I hacked around a bug like this, it had portions in PAM, - apparmor, Seahorse, and Gnome so this time I'd like someone more focused - on broad stability to look at things. + [ Impact ] - The problem is simple. Before the upgrade to 23.10, I could log in - using the "Ubuntu", "Ubuntu on X.org". "Gnome", and "Gnome on X.org" - WMs. Now I can't. I can still login using XFCE and TTY. + gnome-shell may crash on startup due to multiple threads writing and + reading environment variables. + + gnome-shell adds variables like DISPLAY, XAUTHORITY, WAYLAND_DISPLAY to + its own environment. However it might do so while libraries running in + other threads are trying to read environment variables that may affect + their behaviour. If a call to `getenv` is interrupted by a call to + `setenv` that causes re-allocation of memory, it will trigger a crash. + + To mitigate the issue, we avoid starting the fontconfig thread right + before setting the environment variables. + + [ Test Plan ] + + There are no reproducer steps that trigger the crash reliably enough to be verified. + Instead, we are going to verify that the patch does not introduce regressions, and will verify the effectiveness of the fix by monitoring errors.ubuntu.com after the update has landed. + + 1. Install the gnome-shell update + 2. Reboot + 3. Verify that the log-in screen loaded correctly + 4. Log-in + 5. Verify that the desktop loaded correctly + 6. Verify that the font rendering quality is not degraded + + [ Where problems could occur ] + + The patch delays the disablement of text mipmapping to the first time a + font is rendered, instead of doing so on startup. A mistake in the patch + could thus affect font rendering. The test plan asks to verify that that + is not the case.
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2039340 Title: gnome-shell (login screen) crashes with SIGSEGV in __GI_getenv("EXPAT_ACCOUNTING_DEBUG") from getDebugLevel() from parserInit() To manage notifications about this bug go to: https://bugs.launchpad.net/mutter/+bug/2039340/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
