sisfb: fix pseudo_palette array size and overrun

- the pseudo_palette is only 16 elements long.
- do not write to the pseudo_palette if regno (array index) is more than 15.

Signed-off-by: Antonino Daplas <adaplas@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 7 insertions, 1 deletions

diff --git a/drivers/video/sis/sis.h b/drivers/video/sis/sis.h
index d5e2d9c27847..d53bf6945f0c 100644
--- a/drivers/video/sis/sis.h
+++ b/drivers/video/sis/sis.h
@@ -479,7 +479,7 @@ struct sis_video_info {
         struct fb_var_screeninfo default_var;
 
         struct fb_fix_screeninfo sisfb_fix;
-        u32             pseudo_palette[17];
+        u32             pseudo_palette[16];
 
         struct sisfb_monitor {
                 u16 hmin;
diff --git a/drivers/video/sis/sis_main.c b/drivers/video/sis/sis_main.c
index 93d07ef85276..e8ccace01252 100644
--- a/drivers/video/sis/sis_main.c
+++ b/drivers/video/sis/sis_main.c
@@ -1405,12 +1405,18 @@ sisfb_setcolreg(unsigned regno, unsigned red, unsigned green, unsigned blue,
                 }
                 break;
         case 16:
+                if (regno >= 16)
+                        break;
+
                 ((u32 *)(info->pseudo_palette))[regno] =
                                 (red & 0xf800)          |
                                 ((green & 0xfc00) >> 5) |
                                 ((blue & 0xf800) >> 11);
                 break;
         case 32:
+                if (regno >= 16)
+                        break;
+
                 red >>= 8;
                 green >>= 8;
                 blue >>= 8;