Since the introduction of "modesetting: Remove unnecessary fb addition from
drmmode_xf86crtc_resize" the fb_id isn't initialited at
drmmode_xf86crtc_resize.
Rotate operation of XRandR uses rotate_bo. So in this case the fb_id
associated to the front_bo is not initialized at drmmode_set_mode_major.
So fd_id remains 0.
As every call to drmmode_xf86crtc_resize allocates a new front_bo we should
destroy unconditionally the old_front_bo if operation success. So we free
the allocated GBM handles.
This avoids crashing xserver with a OOM in the RPI4 1Gb at 4k resolution
after 3 series xrandr rotations from normal to left and vice versa reported at
https://github.com/raspberrypi/firmware/issues/1345
Signed-off-by: Jose Maria Casanova Crespo <jmcasanova@igalia.com>
Reviewed-by: Keith Packard <keithp@keithp.com>
Closes: https://gitlab.freedesktop.org/xorg/xserver/-/issues/1024
Fixes: 8774532121 "modesetting: Remove unnecessary fb addition from
drmmode_xf86crtc_resize"
73480f172a