Re: [PATCH V2] libxc: Prevent NULL pointer dereference in stdiostream_vmessage()

[Jennifer Herbert <Jennifer.Herbert@citrix.com>]

I guess I didn't build what I thought I built.
V3 coming up

On 07/07/15 16:51, Andrew Cooper wrote:
> On 07/07/15 16:48, Jennifer Herbert wrote:
>> Unlikely that it may seem localtime_r could fail, which would result in a
>> null pointer dereference.  In this case, it shoud log the errno, (instead of
>> the date/time), and and continue its logging, as this is still useful.
>>
>> Signed-off-by: Jennifer Herbert <jennifer.herbert@citrix.com>
>> ---
>>   tools/libxc/xtl_logger_stdio.c |   11 +++++++----
>>   1 file changed, 7 insertions(+), 4 deletions(-)
>>
>> diff --git a/tools/libxc/xtl_logger_stdio.c b/tools/libxc/xtl_logger_stdio.c
>> index d8646e0..5569c50 100644
>> --- a/tools/libxc/xtl_logger_stdio.c
>> +++ b/tools/libxc/xtl_logger_stdio.c
>> @@ -61,10 +61,13 @@ static void stdiostream_vmessage(xentoollog_logger *logger_in,
>>           struct tm lt_buf;
>>           time_t now = time(0);
>>           struct tm *lt= localtime_r(&now, &lt_buf);
>> -        fprintf(lg->f, "%04d-%02d-%02d %02d:%02d:%02d %s ",
>> -                lt->tm_year+1900, lt->tm_mon+1, lt->tm_mday,
>> -                lt->tm_hour, lt->tm_min, lt->tm_sec,
>> -                tzname[!!lt->tm_isdst]);
>> +        if (lt != NULL)
>> +            fprintf(lg->f, "%04d-%02d-%02d %02d:%02d:%02d %s ",
>> +                    lt->tm_year+1900, lt->tm_mon+1, lt->tm_mday,
>> +                    lt->tm_hour, lt->tm_min, lt->tm_sec,
>> +                    tzname[!!lt->tm_isdst]);
>> +        else
>> +            fprintf(lg-f, "[localtime_r failed: %d] ", errno);
> lg->f ?
>
> ~Andrew
>
>>       }
>>       if (lg->flags & XTL_STDIOSTREAM_SHOW_PID)
>>           fprintf(lg->f, "[%lu] ", (unsigned long)getpid());