From 73fe6daa500a9a42075e60ad1f2083099184ce22 Mon Sep 17 00:00:00 2001
From: florian <florian@openbsd.org>
Date: Sun, 28 Apr 2024 16:42:53 +0000
Subject: [PATCH] gmtime(3) / locatime(3) can fail when timestamps are way off.

Add missing error checks to all calls under libexec/

Input & OK millert
---
 libexec/ftpd/ftpcmd.y             |  7 +++++-
 libexec/getty/main.c              | 12 ++++++----
 libexec/snmpd/snmpd_metrics/mib.c | 38 ++++++++++++++++---------------
 libexec/talkd/announce.c          | 13 +++++++----
 4 files changed, 42 insertions(+), 28 deletions(-)

diff --git a/libexec/ftpd/ftpcmd.y b/libexec/ftpd/ftpcmd.y
index e85d7ccb72f..e5d80528a65 100644
--- a/libexec/ftpd/ftpcmd.y
+++ b/libexec/ftpd/ftpcmd.y
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ftpcmd.y,v 1.74 2023/03/08 04:43:05 guenther Exp $	*/
+/*	$OpenBSD: ftpcmd.y,v 1.75 2024/04/28 16:42:53 florian Exp $	*/
 /*	$NetBSD: ftpcmd.y,v 1.7 1996/04/08 19:03:11 jtc Exp $	*/
 
 /*
@@ -613,6 +613,11 @@ cmd
 				} else {
 					struct tm *t;
 					t = gmtime(&stbuf.st_mtime);
+					if (t == NULL) {
+						/* invalid time, use epoch */
+						stbuf.st_mtime = 0;
+						t = gmtime(&stbuf.st_mtime);
+					}
 					reply(213,
 					    "%04d%02d%02d%02d%02d%02d",
 					    1900 + t->tm_year,
diff --git a/libexec/getty/main.c b/libexec/getty/main.c
index 3ac0939d8c8..dac5ad3449b 100644
--- a/libexec/getty/main.c
+++ b/libexec/getty/main.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: main.c,v 1.54 2019/06/28 13:32:53 deraadt Exp $	*/
+/*	$OpenBSD: main.c,v 1.55 2024/04/28 16:42:53 florian Exp $	*/
 
 /*-
  * Copyright (c) 1980, 1993
@@ -562,10 +562,12 @@ putf(char *cp)
 			break;
 
 		case 'd': {
-			(void)time(&t);
-			(void)strftime(db, sizeof(db),
-			    "%l:%M%p on %A, %d %B %Y", localtime(&t));
-			xputs(db);
+			struct tm *tm;
+			time(&t);
+			if ((tm = localtime(&t)) != NULL)
+				if (strftime(db, sizeof(db),
+				    "%l:%M%p on %A, %d %B %Y", tm) != 0)
+					xputs(db);
 			break;
 		}
 
diff --git a/libexec/snmpd/snmpd_metrics/mib.c b/libexec/snmpd/snmpd_metrics/mib.c
index a3b80ddf9ac..2cda1dd0e4e 100644
--- a/libexec/snmpd/snmpd_metrics/mib.c
+++ b/libexec/snmpd/snmpd_metrics/mib.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: mib.c,v 1.7 2023/11/21 08:49:08 martijn Exp $	*/
+/*	$OpenBSD: mib.c,v 1.8 2024/04/28 16:42:53 florian Exp $	*/
 
 /*
  * Copyright (c) 2022 Martijn van Duren <martijn@openbsd.org>
@@ -296,27 +296,29 @@ mib_hrsystemdate(struct agentx_varbind *vb)
 	int		 tzoffset;
 	unsigned short	 year;
 
+	memset(s, 0, sizeof(s));
 	(void)time(&now);
 	ptm = localtime(&now);
 
-	year = htons(ptm->tm_year + 1900);
-	memcpy(s, &year, 2);
-	s[2] = ptm->tm_mon + 1;
-	s[3] = ptm->tm_mday;
-	s[4] = ptm->tm_hour;
-	s[5] = ptm->tm_min;
-	s[6] = ptm->tm_sec;
-	s[7] = 0;
-
-	tzoffset = ptm->tm_gmtoff;
-	if (tzoffset < 0)
-		s[8] = '-';
-	else
-		s[8] = '+';
-
-	s[9] = abs(tzoffset) / 3600;
-	s[10] = (abs(tzoffset) - (s[9] * 3600)) / 60;
+	if (ptm != NULL) {
+		year = htons(ptm->tm_year + 1900);
+		memcpy(s, &year, 2);
+		s[2] = ptm->tm_mon + 1;
+		s[3] = ptm->tm_mday;
+		s[4] = ptm->tm_hour;
+		s[5] = ptm->tm_min;
+		s[6] = ptm->tm_sec;
+		s[7] = 0;
+
+		tzoffset = ptm->tm_gmtoff;
+		if (tzoffset < 0)
+			s[8] = '-';
+		else
+			s[8] = '+';
 
+		s[9] = abs(tzoffset) / 3600;
+		s[10] = (abs(tzoffset) - (s[9] * 3600)) / 60;
+	}
 	agentx_varbind_nstring(vb, s, sizeof(s));
 }
 
diff --git a/libexec/talkd/announce.c b/libexec/talkd/announce.c
index 00bdd0b8c96..10e1b7e7c6d 100644
--- a/libexec/talkd/announce.c
+++ b/libexec/talkd/announce.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: announce.c,v 1.25 2019/06/28 13:32:53 deraadt Exp $	*/
+/*	$OpenBSD: announce.c,v 1.26 2024/04/28 16:42:53 florian Exp $	*/
 
 /*
  * Copyright (c) 1983 Regents of the University of California.
@@ -102,9 +102,14 @@ print_mesg(FILE *tf, CTL_MSG *request, char *remote_machine)
 	sizes[i] = strlen(line_buf[i]);
 	max_size = max(max_size, sizes[i]);
 	i++;
-	(void)snprintf(line_buf[i], N_CHARS,
-	    "Message from Talk_Daemon@%s at %d:%02d ...",
-	    hostname, localclock->tm_hour , localclock->tm_min );
+	if (localclock) {
+		(void)snprintf(line_buf[i], N_CHARS,
+		    "Message from Talk_Daemon@%s at %d:%02d ...",
+		    hostname, localclock->tm_hour , localclock->tm_min );
+	} else {
+		(void)snprintf(line_buf[i], N_CHARS,
+		    "Message from Talk_Daemon@%s ...", hostname);
+	}
 	sizes[i] = strlen(line_buf[i]);
 	max_size = max(max_size, sizes[i]);
 	i++;
-- 
2.20.1