drm/i915: Prevent use-after-free of inherited framebuffer
authorChris Wilson <chris@chris-wilson.co.uk>
Mon, 10 Mar 2014 08:07:01 +0000 (08:07 +0000)
committerDaniel Vetter <daniel.vetter@ffwll.ch>
Mon, 10 Mar 2014 08:18:10 +0000 (09:18 +0100)
commitd1a59868efa65379482c79de997973b06cefb9d2
tree4904b23126e74b5e6b750f2de61a3383992cd8ad
parent484b41dd70a9fbea894632d8926bbb93f05021c7
drm/i915: Prevent use-after-free of inherited framebuffer

During KMS takeover, we try to capture the current configuration and
preserve it across our initialisation. For a variety of reasons, we may
fail this, for example if the current mode was using the legacy VGA
plane. Under such circumstances, we discard the fb in the plane config
and tried to find a matching fb on another CRTC. This obviously also
failed, leaving the plane config fb dangling, pointing to the freed block.

Regression from
commit 484b41dd70a9fbea894632d8926bbb93f05021c7
Author: Jesse Barnes <jbarnes@virtuousgeek.org>
Date:   Fri Mar 7 08:57:55 2014 -0800

    drm/i915: remove early fb allocation dependency on CONFIG_FB v2

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=75963
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
drivers/gpu/drm/i915/intel_display.c