drivers/input/touchscreen/gunze.c: gunze_process_packet: invalid array access

drivers/input/touchscreen/gunze.c: gunze_process_packet: invalid array access

[Adrian Bunk]

The Coverity checker found the following bug in the function 
gunze_process_packet in drivers/input/touchscreen/gunze.c:


<--  snip  -->

...
#define GUNZE_MAX_LENGTH        10
...
struct gunze {
...
        unsigned char data[GUNZE_MAX_LENGTH];
...
};
...
static void gunze_process_packet(struct gunze* gunze, struct pt_regs *regs)
...
                gunze->data[10] = 0;
...

<--  snip  -->


The bug is obvious, but for a correct solution someone should know this 
code better than I do.


cu
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed

Re: drivers/input/touchscreen/gunze.c: gunze_process_packet: invalid array access

[Dmitry Torokhov]

On Tuesday 22 March 2005 20:26, Adrian Bunk wrote:
> The Coverity checker found the following bug in the function 
> gunze_process_packet in drivers/input/touchscreen/gunze.c:
> 
> 
> <--  snip  -->
> 
> ...
> #define GUNZE_MAX_LENGTH        10
> ...
> struct gunze {
> ...
>         unsigned char data[GUNZE_MAX_LENGTH];
> ...
> };
> ...
> static void gunze_process_packet(struct gunze* gunze, struct pt_regs *regs)
> ...
>                 gunze->data[10] = 0;
> ...
> 
> <--  snip  -->
> 
> 
> The bug is obvious, but for a correct solution someone should know this 
> code better than I do.
> 

Ahh, it looks like it was just an attempt to null-terminate packet for
printk. The patch below should do the trick. 

-- 
Dmitry

===================================================================

Input: gunze - fix out-of-bound array access reported by Adrian Bunk.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>


 gunze.c |    3 +--
 1 files changed, 1 insertion(+), 2 deletions(-)

Index: dtor/drivers/input/touchscreen/gunze.c
===================================================================
--- dtor.orig/drivers/input/touchscreen/gunze.c
+++ dtor/drivers/input/touchscreen/gunze.c
@@ -68,8 +68,7 @@ static void gunze_process_packet(struct 
 
 	if (gunze->idx != GUNZE_MAX_LENGTH || gunze->data[5] != ',' ||
 		(gunze->data[0] != 'T' && gunze->data[0] != 'R')) {
-		gunze->data[10] = 0;
-		printk(KERN_WARNING "gunze.c: bad packet: >%s<\n", gunze->data);
+		printk(KERN_WARNING "gunze.c: bad packet: >%.*s<\n", GUNZE_MAX_LENGTH, gunze->data);
 		return;
 	}