Bug 11356

Summary: Busybox used in Motioneye - date setting keeps increasing the year
Product: Busybox Reporter: kenneth lee <kenneth>
Component: OtherAssignee: unassigned
Status: RESOLVED FIXED    
Severity: normal CC: busybox-cvs
Priority: P5    
Version: unspecified   
Target Milestone: ---   
Hardware: All   
OS: Linux   
Host: Target:
Build:

Description kenneth lee 2018-09-15 00:54:02 UTC 
There’s something not quite right with the “date” command in the MotionEye OS which makes use of busybox.
 
I try to set the day to the current date but the resultant year keeps increasing by 1 each time I do a “date –s”
[root@meye-09f2c071 etc]# date +%Y%m%d -s 20180914
20190818
[root@meye-09f2c071 etc]# date +%Y%m%d -s 20180914
20200818
[root@meye-09f2c071 etc]# date +%Y%m%d -s 20180914
20210818
[root@meye-09f2c071 etc]# date +%Y%m%d -s 20180914
20220818
[root@meye-09f2c071 etc]# date +%Y%m%d -s 20180914
20230818

______________________________________________________________________________

Hi Kenneth,

I tried this myself and saw that strange behavior. I don't know what the cause could be for that, but:
•	this looks like a bug in busybox which provides the date implementation, so you could report this problem to then
:
:

On Fri, Sep 14, 2018 at 4:19 AM Kenneth Lee <kleewm@gmail.com> wrote:
Hi Calin,
 
There’s something not quite right with the “date” command in the MotionEye OS.
 
I try to set the day to the current date but the resultant year keeps increasing by 1 each time I do a “date –s”
[root@meye-09f2c071 etc]# date +%Y%m%d -s 20180914
20190818
[root@meye-09f2c071 etc]# date +%Y%m%d -s 20180914
20200818
[root@meye-09f2c071 etc]# date +%Y%m%d -s 20180914
20210818
[root@meye-09f2c071 etc]# date +%Y%m%d -s 20180914
20220818
[root@meye-09f2c071 etc]# date +%Y%m%d -s 20180914
20230818
[root@meye-09f2c071 etc]#
 
Rgds
Kenneth
Comment 1 Denys Vlasenko 2018-09-23 18:12:24 UTC 
'20180914' does not mean what you think it means. At least for busybox:

$ date --help
BusyBox v1.30.0.git (2018-08-01 13:57:11 CEST) multi-call binary.

Usage: date [OPTIONS] [+FMT] [TIME]

Display time (using +FMT), or set time

	[-s,--set] TIME	Set time to TIME
	-u,--utc	Work in UTC (don't convert to local time)
	-R,--rfc-2822	Output RFC-2822 compliant date string
	-I[SPEC]	Output ISO-8601 compliant date string
			SPEC='date' (default) for date only,
			'hours', 'minutes', or 'seconds' for date and
			time to the indicated precision
	-r,--reference FILE	Display last modification time of FILE
	-d,--date TIME	Display TIME, not 'now'
	-D FMT		Use FMT for -d TIME conversion

Recognized TIME formats:
	hh:mm[:ss]
	[YYYY.]MM.DD-hh:mm[:ss]
	YYYY-MM-DD hh:mm[:ss]
	[[[[[YY]YY]MM]DD]hh]mm[.ss]

20180914 matches only MMDDhhmm pattern.
Comment 2 Denys Vlasenko 2018-09-23 19:45:40 UTC 
Fixed:

commit 76832ff5c4f107f8a8165fcafc9b05a888cdb964
Date:   Sun Sep 23 20:27:32 2018 +0200

    date: do not allow "month #20" and such, closes 11356

    function                                             old     new   delta
    parse_datestr                                        906     961     +55

    Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/libbb/time.c b/libbb/time.c
index 82e6cb172..f9b8da0b3 100644
--- a/libbb/time.c
+++ b/libbb/time.c
@@ -184,6 +184,7 @@ void FAST_FUNC parse_datestr(const char *date_str, struct tm *ptm)
                        ptm->tm_year -= 1900; /* Adjust years */
                        ptm->tm_mon -= 1; /* Adjust month from 1-12 to 0-11 */
                } else {
+ err:
                        bb_error_msg_and_die(bb_msg_invalid_date, date_str);
                }
                ptm->tm_sec = 0; /* assume zero if [.SS] is not given */
@@ -194,6 +195,19 @@ void FAST_FUNC parse_datestr(const char *date_str, struct tm *ptm)
                                end = '\0';
                        /* else end != NUL and we error out */
                }
+               /* Users were confused by "date -s 20180923"
+                * working (not in the way they were expecting).
+                * It was interpreted as MMDDhhmm, and not bothered by
+                * "month #20" in the least. Prevent such cases:
+                */
+               if (ptm->tm_sec > 60 /* allow "23:60" leap second */
+                || ptm->tm_min > 59
+                || ptm->tm_hour > 23
+                || ptm->tm_mday > 31
+                || ptm->tm_mon > 11 /* month# is 0..11, not 1..12 */
+               ) {
+                       goto err;
+               }