cifs: small underflow in cnvrtDosUnixTm()

January is month 1.  There is no zero-th month.  If someone passes a
zero month then it means we read from one space before the start of the
total_days_of_prev_months[] array.

We may as well also be strict about days as well.

Fixes: 1bd5bbcb65 ("[CIFS] Legacy time handling for Win9x and OS/2 part 1")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steve French <smfrench@gmail.com>
This commit is contained in:
Dan Carpenter 2017-05-01 21:43:43 +03:00 committed by Steve French
parent 204f144c9f
commit 564277ecee

View File

@ -980,10 +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 < 1 || days > 31 || month < 1 || month > 12) {
cifs_dbg(VFS, "illegal date, month %d day: %d\n", month, days);
if (month > 12)
month = 12;
days = clamp(days, 1, 31);
month = clamp(month, 1, 12);
}
month -= 1;
days += total_days_of_prev_months[month];