On Thu, Jul 6, 2017 at 8:04 AM, Denys Vlasenko <vda.li...@googlemail.com> wrote:
> On Tue, Jun 27, 2017 at 3:20 PM, Kang-Che Sung <explore...@gmail.com> wrote:
>> Hello. Can I suggest another way?
>> How about modifying the `line` buffer so it can be used directly as the name,
>> and avoid the malloc problem or STRINGIFY(PATH_MAX) altogether.
>>
>> My suggestion (warning, this code is not tested):
>>
>> --- a/miscutils/makedevs.c
>> +++ b/miscutils/makedevs.c
>> @@ -209,23 +209,27 @@ int makedevs_main(int argc UNUSED_PARAM, char **argv)
>> unsigned increment = 0;
>> unsigned start = 0;
>> char name[41];
>> + int name_len;
>> char user[41];
>> char group[41];
>> - char *full_name = name;
>> + char *full_name;
>> uid_t uid;
>> gid_t gid;
>>
>> linenum = parser->lineno;
>>
>> - if ((2 > sscanf(line, "%40s %c %o %40s %40s %u %u %u %u %u",
>> - name, &type, &mode, user, group,
>> + if ((1 > sscanf(line, "%*s%n %c %o %40s %40s %u %u %u %u %u",
>> + &name_len, &type, &mode, user, group,
>> &major, &minor, &start, &increment, &count))
>> + || (PATH_MAX > name_len + 1)
>> || ((unsigned)(major | minor | start | count | increment) > 255)
>> ) {
>> bb_error_msg("invalid line %d: '%s'", linenum, line);
>> ret = EXIT_FAILURE;
>> continue;
>> }
>> + line[name_len] = '\0';
>> + full_name = line;
>
> Good idea!
>
> Applied, thanks!
Wait. I was not expecting the patch be applied directly. I was expecting it
be tested first.
I think my code has a bug:
If the line begins with whitespaces, the initial whitespaces will be included
in `full_name` while the original code won't.
Denys Vlasenko, are you willing to look at this problem?
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