[PATCH] cifs: small underflow in cnvrtDosUnixTm()

[Steve French]

Jim's suggestion seems like reasonable improvement

On Mon, Apr 10, 2017 at 10:43 AM, jim via samba-technical
<samba-technical at lists.samba.org> wrote:
> Restrict days > 31 to 31?
> What about days < 1? Test and restrict to 1?
>
>
> On 4/10/2017 9:49 AM, Dan Carpenter via samba-technical wrote:
>>
>> January is month 1.  There is no zero-th month.  We don't care very much
>> if the days are invalid but for months, we use it to read from an array
>> so this bug means we read one space before the start of the
>> total_days_of_prev_months[] array.
>>
>> Fixes: 1bd5bbcb6531 ("[CIFS] Legacy time handling for Win9x and OS/2 part
>> 1")
>> Signed-off-by: Dan Carpenter <dan.carpenter at oracle.com>
>>
>> diff --git a/fs/cifs/netmisc.c b/fs/cifs/netmisc.c
>> index abae6dd2c6b9..f1f64a15215a 100644
>> --- a/fs/cifs/netmisc.c
>> +++ b/fs/cifs/netmisc.c
>> @@ -980,8 +980,10 @@ struct timespec cnvrtDosUnixTm(__le16 le_date, __le16
>> le_time, int offset)
>>                 cifs_dbg(VFS, "illegal hours %d\n", st->Hours);
>>         days = sd->Day;
>>         month = sd->Month;
>> -       if ((days > 31) || (month > 12)) {
>> +       if (days > 31 || month < 1 || month > 12) {
>>                 cifs_dbg(VFS, "illegal date, month %d day: %d\n", month,
>> days);
>> +               if (month < 1)
>> +                       month = 1;
>>                 if (month > 12)
>>                         month = 12;
>>         }
>>
>
>



-- 
Thanks,

Steve