drm: Validate requested virtual size against allocated fb size
authorChris Wilson <chris@chris-wilson.co.uk>
Mon, 26 Mar 2012 20:15:53 +0000 (21:15 +0100)
committerDave Airlie <airlied@redhat.com>
Tue, 3 Apr 2012 10:18:46 +0000 (11:18 +0100)
commit62fb376e214d3c1bfdf6fbb77dac162f6da04d7e
treee740485e5c058ad0f8e22f26081c24014e127d5a
parente199fd422420d1620cf64fd9bdd4ff8bc255cc76
drm: Validate requested virtual size against allocated fb size

mplayer -vo fbdev tries to create a screen that is twice as tall as the
allocated framebuffer for "doublebuffering". By default, and all in-tree
users, only sufficient memory is allocated and mapped to satisfy the
smallest framebuffer and the virtual size is no larger than the actual.
For these users, we should therefore reject any userspace request to
create a screen that requires a buffer larger than the framebuffer
originally allocated.

References: https://bugs.freedesktop.org/show_bug.cgi?id=38138
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: stable@kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
drivers/gpu/drm/drm_fb_helper.c