fbdev: atafb - add palette register check

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

Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/video/atafb.c b/drivers/video/atafb.c
index 37624f74e88b..b7687c55fe16 100644
--- a/drivers/video/atafb.c
+++ b/drivers/video/atafb.c
@@ -2242,6 +2242,9 @@ static int ext_setcolreg(unsigned int regno, unsigned int red,
         if (!external_vgaiobase)
                 return 1;
 
+        if (regno > 255)
+                return 1;
+
         switch (external_card_type) {
         case IS_VGA:
                 OUTB(0x3c8, regno);