From: Deepa Dinamani <deepa.kernel@gmail.com>
Date: Fri, 22 Mar 2019 14:32:35 -0700
Subject: [PATCH] fs: cifs: Initialize filesystem timestamp ranges
Git-commit: cb7a69e605908c34aad47644afeb26a765ade8d7
References: bsc#1144333
Patch-mainline: v5.3-rc7

Fill in the appropriate limits to avoid inconsistencies
in the vfs cached inode times when timestamps are
outside the permitted range.

Also fixed cnvrtDosUnixTm calculations to avoid int overflow
while computing maximum date.

 References:

http://cifs.com/

https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-cifs/d416ff7c-c536-406e-a951-4f04b2fd1d2b

Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Acked-by: Jeff Layton <jlayton@kernel.org>
Cc: sfrench@samba.org
Cc: linux-cifs@vger.kernel.org
Acked-by: Paulo Alcantara <palcantara@suse.de>
---
 fs/cifs/netmisc.c |   13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

--- a/fs/cifs/netmisc.c
+++ b/fs/cifs/netmisc.c
@@ -962,7 +962,8 @@ static const int total_days_of_prev_mont
 struct timespec cnvrtDosUnixTm(__le16 le_date, __le16 le_time, int offset)
 {
 	struct timespec ts;
-	int sec, min, days, month, year;
+	int sec, days;
+	int min, day, month, year;
 	u16 date = le16_to_cpu(le_date);
 	u16 time = le16_to_cpu(le_time);
 	SMB_TIME *st = (SMB_TIME *)&time;
@@ -978,15 +979,15 @@ struct timespec cnvrtDosUnixTm(__le16 le
 	sec += 60 * 60 * st->Hours;
 	if (st->Hours > 24)
 		cifs_dbg(VFS, "illegal hours %d\n", st->Hours);
-	days = sd->Day;
+	day = sd->Day;
 	month = sd->Month;
-	if (days < 1 || days > 31 || month < 1 || month > 12) {
-		cifs_dbg(VFS, "illegal date, month %d day: %d\n", month, days);
-		days = clamp(days, 1, 31);
+	if (day < 1 || day > 31 || month < 1 || month > 12) {
+		cifs_dbg(VFS, "illegal date, month %d day: %d\n", month, day);
+		day = clamp(day, 1, 31);
 		month = clamp(month, 1, 12);
 	}
 	month -= 1;
-	days += total_days_of_prev_months[month];
+	days = day + total_days_of_prev_months[month];
 	days += 3652; /* account for difference in days between 1980 and 1970 */
 	year = sd->Year;
 	days += year * 365;