[PATCH] vsscanf do not convert hex numbers starting with a non-digit

[PATCH] vsscanf do not convert hex numbers starting with a non-digit

[Torsten Foertsch]

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Hi,

I found the following little bug in 2.4.19. I did not try newer kernels.

vsscanf refuses to convert a hex number starting with a nondecimal digit like:

char *buf="ff";
unsigned ff=0;
sscanf( buf, "%x", &ff );      /* fails: nothing is converted */

Here is a patch that corrects that behaviour:

- --- linux/lib/vsprintf.c        2001-10-11 20:17:22.000000000 +0200
+++ linux.patched/lib/vsprintf.c        2003-03-11 11:52:08.000000000 +0100
@@ -637,7 +637,7 @@
                while (isspace(*str))
                        str++;
 
- -               if (!*str || !isdigit(*str))
+               if (!*str || !(isdigit(*str) || (base==16 && isxdigit(*str))))
                        break;
 
                switch(qualifier) {


Torsten
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Re: [PATCH] vsscanf do not convert hex numbers starting with a non-digit

[Marc-Christian Petersen]

On Tuesday 11 March 2003 12:02, Torsten Foertsch wrote:

Hi Torsten,


> I found the following little bug in 2.4.19. I did not try newer kernels.
> vsscanf refuses to convert a hex number starting with a nondecimal digit
> like:
> char *buf="ff";
> unsigned ff=0;
> sscanf( buf, "%x", &ff );      /* fails: nothing is converted */
>
> Here is a patch that corrects that behaviour:
>
> --- linux/lib/vsprintf.c        2001-10-11 20:17:22.000000000 +0200
> +++ linux.patched/lib/vsprintf.c        2003-03-11 11:52:08.000000000 +0100
> @@ -637,7 +637,7 @@
>                 while (isspace(*str))
>                         str++;
>
> -               if (!*str || !isdigit(*str))
> +               if (!*str || !(isdigit(*str) || (base==16 &&
> isxdigit(*str)))) break;
>
>                 switch(qualifier) {

http://marc.theaimsgroup.com/?l=linux-kernel&m=104687957102846&w=2

This fix was first posted since early 2.4.18-pre stage.

ciao, Marc