From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Carpenter Subject: [PATCH] cifs: small underflow in cnvrtDosUnixTm() Date: Mon, 10 Apr 2017 16:49:31 +0300 Message-ID: <20170410134931.GC1918@mwanda> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-cifs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, samba-technical-w/Ol4Ecudpl8XjKLYN78aQ@public.gmane.org, kernel-janitors-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Steve French Return-path: Content-Disposition: inline Sender: linux-cifs-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: 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 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; }