tridentfb: fix pseudo_palette array overrun in setcolreg

The pseudo_palette has only 16 elements. Do not write if regno (the 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>

1 files changed, 16 insertions, 14 deletions

diff --git a/drivers/video/tridentfb.c b/drivers/video/tridentfb.c
index 55e8aa450bfa..c699864b6f4a 100644
--- a/drivers/video/tridentfb.c
+++ b/drivers/video/tridentfb.c
@@ -976,7 +976,7 @@ static int tridentfb_setcolreg(unsigned regno, unsigned red, unsigned green,
                 return 1;
 
 
-        if (bpp==8) {
+        if (bpp == 8) {
                 t_outb(0xFF,0x3C6);
                 t_outb(regno,0x3C8);
 
@@ -984,19 +984,21 @@ static int tridentfb_setcolreg(unsigned regno, unsigned red, unsigned green,
                 t_outb(green>>10,0x3C9);
                 t_outb(blue>>10,0x3C9);
 
-        } else if (bpp == 16) { /* RGB 565 */
-                u32 col;
-
-                col = (red & 0xF800) | ((green & 0xFC00) >> 5) |
-                        ((blue & 0xF800) >> 11);
-                col |= col << 16;       
-                ((u32 *)(info->pseudo_palette))[regno] = col;
-        } else if (bpp == 32)           /* ARGB 8888 */
-                ((u32*)info->pseudo_palette)[regno] =
-                        ((transp & 0xFF00) <<16)        |
-                        ((red & 0xFF00) << 8)           |
-                        ((green & 0xFF00))              |
-                        ((blue & 0xFF00)>>8);
+        } else if (regno < 16) {
+                if (bpp == 16) {        /* RGB 565 */
+                        u32 col;
+
+                        col = (red & 0xF800) | ((green & 0xFC00) >> 5) |
+                                ((blue & 0xF800) >> 11);
+                        col |= col << 16;
+                        ((u32 *)(info->pseudo_palette))[regno] = col;
+                } else if (bpp == 32)           /* ARGB 8888 */
+                        ((u32*)info->pseudo_palette)[regno] =
+                                ((transp & 0xFF00) <<16)        |
+                                ((red & 0xFF00) << 8)           |
+                                ((green & 0xFF00))              |
+                                ((blue & 0xFF00)>>8);
+        }
 
 //      debug("exit\n");
         return 0;