fbdev: add palette register check to several drivers

Add check if palette register number is in correct range for few drivers
which miss it.  The regno value comes indirectly from user space.

Two drivers has converted check from BUG_ON() macro to just return an
error (non-zero value).

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, 3 insertions, 0 deletions

diff --git a/drivers/video/atafb.c b/drivers/video/atafb.c
index b7687c55fe16..2051c9dc813b 100644
--- a/drivers/video/atafb.c
+++ b/drivers/video/atafb.c
@@ -2245,6 +2245,9 @@ static int ext_setcolreg(unsigned int regno, unsigned int red,
         if (regno > 255)
                 return 1;
 
+        if (regno > 255)
+                return 1;
+
         switch (external_card_type) {
         case IS_VGA:
                 OUTB(0x3c8, regno);