https://bugs.freedesktop.org/show_bug.cgi?id=75279 --- Comment #29 from Frederic Bezies --- Looks like a NouVeau is triggered by Mozilla Firefox trunk code. I opened a bug on mozilla bugtracker, https://bugzilla.mozilla.org/show_bug.cgi?id=978439 Even if I find a "dirty workaround", valgrind logs are showing a NouVeau driver bug. I will attach both Mozilla Firefox valgrind log and glxtest one. But there is a common part : Invalid read of size 4 at 0x8DBA0BE: nouveau_fence_wait (nouveau_fence.c:205) by 0x8E4AFF4: nv50_screen_destroy (nv50_screen.c:293) by 0x8DAACDE: dri_destroy_screen_helper (dri_screen.c:378) by 0x8DAAD74: dri_destroy_screen (dri_screen.c:388) by 0x8AB13D6: driDestroyScreen (dri_util.c:234) by 0x69A06C1: dri2DestroyScreen (dri2_glx.c:712) by 0x697CFE5: FreeScreenConfigs.isra.3 (glxext.c:208) by 0x697D064: glx_display_free (glxext.c:231) by 0x697D164: __glXCloseDisplay (glxext.c:272) by 0x50569F1: XCloseDisplay (in /usr/lib/libX11.so.6.3.0) -- You are receiving this mail because: You are the assignee for the bug.