[Fontconfig] fontconfig: Branch 'master'

[Behdad Esfahbod]

Damn. It wasn't exactly compiler-catchable.  Thanks for the catch.  Fixed.

On 13-01-17 07:21 PM, Raimund Steger wrote:
> Behdad Esfahbod wrote:
>> [...]
>> diff --git a/src/fcdefault.c b/src/fcdefault.c
>> index 88978b8..2d7c4f7 100644
>> --- a/src/fcdefault.c
>> +++ b/src/fcdefault.c
>> [...]
>> -    char buf[8192];
>> +    char buf[PATH_MAX + 1];
>>       unsigned int len;
> 
> I think something can still go wrong there: readlink can return -1, but due to
> 'len' being unsigned it can enter the 'if' branch.
> 
> If I simulate a readlink failure by using an invalid path:
> 
> 
> [...]
> (gdb) run
> Starting program: /home/rs/testing/fontconfig-git/bin/fc-match
> [Thread debugging using libthread_db enabled]
> 
> Breakpoint 1, FcGetPrgname () at fcdefault.c:115
> 115         prgname = fc_atomic_ptr_get (&default_prgname);
> (gdb) next
> 116         if (!prgname)
> (gdb) next
> 152             char *p = NULL;
> (gdb) next
> 154             len = readlink ("/proc/self/exeINVALID", buf, sizeof (buf) - 1);
> (gdb) next
> 155             if (len > 0)
> (gdb) print len
> $1 = 4294967295
> (gdb) next
> 157                 buf[len] = '\0';
> (gdb)
> 
> 
> It works if I use 'int'. (See patch.)
> 
> Raimund
> 
> 
> 
> 
> 
> 
> 
> 
> 
>> +    char *p = NULL;
>>
>> +#if defined (HAVE_GETPROGNAME) && defined (HAVE_REALPATH)
>> +    const char *q = getprogname ();
>> +    if (q)
>> +        p = realpath (q, buf);
>> +#else
>>       len = readlink ("/proc/self/exe", buf, sizeof (buf) - 1);
>>       if (len > 0)
>>       {
>> -        char *p;
>> +        buf[len] = '\0';
>> +        p = buf;
>> +    }
>> +#endif
>>
>> -        p = strrchr (buf, '/');
>> -        if (p)
>> -        p++;
>> +    if (p)
>> +    {
>> +        char *r = strrchr (p, '/');
>> +        if (r)
>> +        r++;
>>           else
>> -        p = buf;
>> +        r = p;
>>
>> -        prgname = FcStrdup (p);
>> +        prgname = FcStrdup (r);
>>       }
>> -#endif
>>
>>       if (!prgname)
>>           prgname = FcStrdup ("");
>> @@ -175,6 +176,7 @@ retry:
>>           free (prgname);
>>           goto retry;
>>       }
>> +#endif
>>       }
>>
>>       if (prgname && !prgname[0])
>> _______________________________________________
>> Fontconfig mailing list
>> Fontconfig at lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/fontconfig
>>
> 
> 

-- 
behdad
http://behdad.org/