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>

5 files changed, 12 insertions, 2 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);
diff --git a/drivers/video/ep93xx-fb.c b/drivers/video/ep93xx-fb.c
index bd9d46f95291..27aab4a06198 100644
--- a/drivers/video/ep93xx-fb.c
+++ b/drivers/video/ep93xx-fb.c
@@ -358,6 +358,8 @@ static int ep93xxfb_setcolreg(unsigned int regno, unsigned int red,
 
         switch (info->fix.visual) {
         case FB_VISUAL_PSEUDOCOLOR:
+                if (regno > 255)
+                        return 1;
                 rgb = ((red & 0xff00) << 8) | (green & 0xff00) |
                         ((blue & 0xff00) >> 8);
 
diff --git a/drivers/video/maxinefb.c b/drivers/video/maxinefb.c
index 5e91c2b30af9..7854c7a37dc5 100644
--- a/drivers/video/maxinefb.c
+++ b/drivers/video/maxinefb.c
@@ -92,6 +92,9 @@ static int maxinefb_setcolreg(unsigned regno, unsigned red, unsigned green,
         /* value to be written into the palette reg. */
         unsigned long hw_colorvalue = 0;
 
+        if (regno > 255)
+                return 1;
+
         red   >>= 8;    /* The cmap fields are 16 bits    */
         green >>= 8;    /* wide, but the harware colormap */
         blue  >>= 8;    /* registers are only 8 bits wide */
diff --git a/drivers/video/pmag-ba-fb.c b/drivers/video/pmag-ba-fb.c
index 0573ec685a57..0f361b6100d2 100644
--- a/drivers/video/pmag-ba-fb.c
+++ b/drivers/video/pmag-ba-fb.c
@@ -98,7 +98,8 @@ static int pmagbafb_setcolreg(unsigned int regno, unsigned int red,
 {
         struct pmagbafb_par *par = info->par;
 
-        BUG_ON(regno >= info->cmap.len);
+        if (regno >= info->cmap.len)
+                return 1;
 
         red   >>= 8;    /* The cmap fields are 16 bits    */
         green >>= 8;    /* wide, but the hardware colormap */
diff --git a/drivers/video/pmagb-b-fb.c b/drivers/video/pmagb-b-fb.c
index 98748723af9f..2de0806421b4 100644
--- a/drivers/video/pmagb-b-fb.c
+++ b/drivers/video/pmagb-b-fb.c
@@ -102,7 +102,8 @@ static int pmagbbfb_setcolreg(unsigned int regno, unsigned int red,
 {
         struct pmagbbfb_par *par = info->par;
 
-        BUG_ON(regno >= info->cmap.len);
+        if (regno >= info->cmap.len)
+                return 1;
 
         red   >>= 8;    /* The cmap fields are 16 bits    */
         green >>= 8;    /* wide, but the hardware colormap */