cirrusfb: do not allow unsupported pixel depth

Do not allow modes with unsupported pixel depth.  Otherwise, one can hang
a computer by setting incorrect value with fbset command.

Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 3 deletions

diff --git a/drivers/video/cirrusfb.c b/drivers/video/cirrusfb.c
index d42e385f091c..4c2bf923418c 100644
--- a/drivers/video/cirrusfb.c
+++ b/drivers/video/cirrusfb.c
@@ -567,9 +567,7 @@ static int cirrusfb_check_var(struct fb_var_screeninfo *var,
         default:
                 dev_dbg(info->device,
                         "Unsupported bpp size: %d\n", var->bits_per_pixel);
-                assert(false);
-                /* should never occur */
-                break;
+                return -EINVAL;
         }
 
         if (var->xres_virtual < var->xres)