Fix segfaults on bogus localtime input.

The return code from localtime() function (and also gmtime() one)
wasn't checked. In some (rare) cases, it can return a NULL pointer
resulting in a segmentation fault.
The return code is now checked, but no specific action is performed
anyway.

Original patch from Ivana Varekova from RedHat (04/10/2010):
diff -up sysstat-9.0.6.1/sar.c.pom sysstat-9.0.6.1/sar.c
--- sysstat-9.0.6.1/sar.c.pom	2009-10-17 15:08:21.000000000 +0200
+++ sysstat-9.0.6.1/sar.c	2010-10-04 12:21:13.383442188 +0200
@@ -247,7 +247,7 @@ void reverse_check_act(unsigned int act_
  * @curr	Index in array for current sample statistics.
  ***************************************************************************
 */
-void sar_get_record_timestamp_struct(int curr)
+int  sar_get_record_timestamp_struct(int curr)
 {
 	struct tm *ltm;

@@ -257,10 +257,17 @@ void sar_get_record_timestamp_struct(int
 		rectime.tm_hour = record_hdr[curr].hour;
 		rectime.tm_min  = record_hdr[curr].minute;
 		rectime.tm_sec  = record_hdr[curr].second;
+		return 0;
 	}
 	else {
 		ltm = localtime((const time_t *) &record_hdr[curr].ust_time);
+
+		/* localtime procedure could not finish successful */
+		if (ltm == NULL)
+			return 1;
+
 		rectime = *ltm;
+		return 0;
 	}
 }

@@ -312,13 +319,17 @@ int check_line_hdr(void)
  * @cur_time	Timestamp string.
  ***************************************************************************
 */
-void set_record_timestamp_string(int curr, char *cur_time, int len)
+int set_record_timestamp_string(int curr, char *cur_time, int len)
 {
+	int ret;
 	/* Fill timestamp structure */
-	sar_get_record_timestamp_struct(curr);
+	ret = sar_get_record_timestamp_struct(curr);
+	if (ret != 0)
+		return ret;

 	/* Set cur_time date value */
 	strftime(cur_time, len, "%X", &rectime);
+	return 0;
 }

 /*
@@ -407,6 +418,7 @@ int write_stats(int curr, int read_from_
 		int use_tm_end, int reset, unsigned int act_id)
 {
 	int i;
+	int ret;
 	unsigned long long itv, g_itv;
 	static int cross_day = 0;
 	static __nr_t cpu_nr = -1;
@@ -423,9 +435,14 @@ int write_stats(int curr, int read_from_
 	}

 	/* Set previous timestamp */
-	set_record_timestamp_string(!curr, timestamp[!curr], 16);
+	ret = set_record_timestamp_string(!curr, timestamp[!curr], 16);
+	if (ret != 0)
+		return ret;
+
 	/* Set current timestamp */
-	set_record_timestamp_string(curr,  timestamp[curr],  16);
+	ret = set_record_timestamp_string(curr,  timestamp[curr],  16);
+	if (ret != 0)
+		return ret;

 	/* Check if we are beginning a new day */
 	if (use_tm_start && record_hdr[!curr].ust_time &&
@@ -569,8 +586,11 @@ int sar_print_special(int curr, int use_
 {
 	char cur_time[26];
 	int dp = 1;
+	int ret;

-	set_record_timestamp_string(curr, cur_time, 26);
+	ret = set_record_timestamp_string(curr, cur_time, 26);
+	if (ret != 0)
+		return ret;

 	/* The record must be in the interval specified by -s/-e options */
 	if ((use_tm_start && (datecmp(&rectime, &tm_start) < 0)) ||
@@ -865,7 +885,8 @@ void read_stats_from_file(char from_file
 				 */
 				read_file_stat_bunch(act, 0, ifd, file_hdr.sa_nr_act,
 						     file_actlst);
-				sar_get_record_timestamp_struct(0);
+				if (sar_get_record_timestamp_struct(0))
+					continue;
 			}
 		}
 		while ((rtype == R_RESTART) || (rtype == R_COMMENT) ||

diff --git a/CHANGES b/CHANGES
index 6871da8434014fe3afd7b8c44d6966219a6e772f..4f1d2e1691948dabd9b39c4471c36bdd65b316c4 100644 (file)
--- a/CHANGES
+++ b/CHANGES
@@ -3,6 +3,7 @@ Changes:
 xxxx/xx/xx: Version 9.1.7 - Sebastien Godard (sysstat <at> orange.fr)
        * sar now tells sadc to read only the necessary groups of
          activities.
+       * [Ivana Varekova]: Fix segfaults on bogus localtime input.
        * sar manual page updated.
 
 2010/11/10: Version 9.1.6 - Sebastien Godard (sysstat <at> orange.fr)

diff --git a/common.c b/common.c
index 9d64eaac84201f29a4f44fa3e5bf2269662b42c4..48c8368642280202b0a23779fa70f54ef936ecc5 100644 (file)
--- a/common.c
+++ b/common.c
@@ -285,7 +285,10 @@ int print_gal_header(struct tm *rectime, char *sysname, char *release,
        char *e;
        int rc = 0;
 
-       if (((e = getenv(ENV_TIME_FMT)) != NULL) && !strcmp(e, K_ISO)) {
+       if (rectime == NULL) {
+               strcpy(cur_date, "?/?/?");
+       }
+       else if (((e = getenv(ENV_TIME_FMT)) != NULL) && !strcmp(e, K_ISO)) {
                strftime(cur_date, sizeof(cur_date), "%Y-%m-%d", rectime);
                rc = 1;
        }

diff --git a/sa_common.c b/sa_common.c
index d0ecc2ea2b42a3198cdb63892c5a5709b4f8b285..ab2e6e8668170ff68baf7037c53487db15f726e3 100644 (file)
--- a/sa_common.c
+++ b/sa_common.c
@@ -382,8 +382,9 @@ void get_file_timestamp_struct(unsigned int flags, struct tm *rectime,
                mktime(rectime);
        }
        else {
-               loc_t = localtime((const time_t *) &file_hdr->sa_ust_time);
-               *rectime = *loc_t;
+               if ((loc_t = localtime((const time_t *) &file_hdr->sa_ust_time)) != NULL) {
+                       *rectime = *loc_t;
+               }
        }
 }
 

diff --git a/sadf.c b/sadf.c
index 3739127dcc01b1581cbf92cff35aefdd4f432cdf..77379e714db621f031d37487bb06ae6e372b6d28 100644 (file)
--- a/sadf.c
+++ b/sadf.c
@@ -125,8 +125,9 @@ void sadf_get_record_timestamp_struct(int curr)
 {
        struct tm *ltm;
 
-       ltm = localtime((const time_t *) &record_hdr[curr].ust_time);
-       loctime = *ltm;
+       if ((ltm = localtime((const time_t *) &record_hdr[curr].ust_time)) != NULL) {
+               loctime = *ltm;
+       }
 
        if (!PRINT_TRUE_TIME(flags) ||
            ((format != S_O_DB_OPTION) && (format != S_O_XML_OPTION))) {
@@ -134,7 +135,9 @@ void sadf_get_record_timestamp_struct(int curr)
                ltm = gmtime((const time_t *) &record_hdr[curr].ust_time);
        }
 
-       rectime = *ltm;
+       if (ltm) {
+               rectime = *ltm;
+       }
 }
 
 /*

diff --git a/sar.c b/sar.c
index 9fcc0f76c6d5298e4b0521e34d596b28e6f3204f..69b970926e5db6cf790596b2bdce9be3d51ad39c 100644 (file)
--- a/sar.c
+++ b/sar.c
@@ -245,17 +245,20 @@ void reverse_check_act(unsigned int act_nr)
 
 /*
  ***************************************************************************
- * Fill the rectime structure with current record's time, based on current
- * record's time data saved in file.
+ * Fill the (struct tm) rectime structure with current record's time,
+ * based on current record's time data saved in file.
  * The resulting timestamp is expressed in the locale of the file creator
  * or in the user's own locale depending on whether option -t has been used
  * or not.
  *
  * IN:
  * @curr       Index in array for current sample statistics.
+ *
+ * RETURNS:
+ * 1 if an error was detected, or 0 otherwise.
  ***************************************************************************
 */
-void sar_get_record_timestamp_struct(int curr)
+int sar_get_record_timestamp_struct(int curr)
 {
        struct tm *ltm;
 
@@ -267,9 +270,17 @@ void sar_get_record_timestamp_struct(int curr)
                rectime.tm_sec  = record_hdr[curr].second;
        }
        else {
-               ltm = localtime((const time_t *) &record_hdr[curr].ust_time);
+               if ((ltm = localtime((const time_t *) &record_hdr[curr].ust_time)) == NULL)
+                       /*
+                        * An error was detected.
+                        * The rectime structure has NOT been updated.
+                        */
+                       return 1;
+               
                rectime = *ltm;
        }
+       
+       return 0;
 }
 
 /*
@@ -318,15 +329,22 @@ int check_line_hdr(void)
  *
  * OUT:
  * @cur_time   Timestamp string.
+ *
+ * RETURNS:
+ * 1 if an error was detected, or 0 otherwise.
  ***************************************************************************
 */
-void set_record_timestamp_string(int curr, char *cur_time, int len)
+int set_record_timestamp_string(int curr, char *cur_time, int len)
 {
        /* Fill timestamp structure */
-       sar_get_record_timestamp_struct(curr);
+       if (sar_get_record_timestamp_struct(curr))
+               /* Error detected */
+               return 1;
 
        /* Set cur_time date value */
        strftime(cur_time, len, "%X", &rectime);
+
+       return 0;
 }
 
 /*
@@ -408,7 +426,7 @@ void write_stats_avg(int curr, int read_from_file, unsigned int act_id)
  * @cnt                        Number of remaining lines to display.
  *
  * RETURNS:
- * 1 if stats have been successfully displayed.
+ * 1 if stats have been successfully displayed, and 0 otherwise.
  ***************************************************************************
  */
 int write_stats(int curr, int read_from_file, long *cnt, int use_tm_start,
@@ -431,9 +449,11 @@ int write_stats(int curr, int read_from_file, long *cnt, int use_tm_start,
        }
 
        /* Set previous timestamp */
-       set_record_timestamp_string(!curr, timestamp[!curr], 16);
+       if (set_record_timestamp_string(!curr, timestamp[!curr], 16))
+               return 0;
        /* Set current timestamp */
-       set_record_timestamp_string(curr,  timestamp[curr],  16);
+       if (set_record_timestamp_string(curr,  timestamp[curr],  16))
+               return 0;
 
        /* Check if we are beginning a new day */
        if (use_tm_start && record_hdr[!curr].ust_time &&
@@ -571,7 +591,7 @@ int sa_read(void *buffer, int size)
  * @ifd                        Input file descriptor.
  *
  * RETURNS:
- * 1 if the record has been successfully displayed.
+ * 1 if the record has been successfully displayed, and 0 otherwise.
  ***************************************************************************
  */
 int sar_print_special(int curr, int use_tm_start, int use_tm_end, int rtype, int ifd)
@@ -579,7 +599,8 @@ int sar_print_special(int curr, int use_tm_start, int use_tm_end, int rtype, int
        char cur_time[26];
        int dp = 1;
 
-       set_record_timestamp_string(curr, cur_time, 26);
+       if (set_record_timestamp_string(curr, cur_time, 26))
+               return 0;
 
        /* The record must be in the interval specified by -s/-e options */
        if ((use_tm_start && (datecmp(&rectime, &tm_start) < 0)) ||
@@ -879,7 +900,12 @@ void read_stats_from_file(char from_file[])
                                 */
                                read_file_stat_bunch(act, 0, ifd, file_hdr.sa_nr_act,
                                                     file_actlst);
-                               sar_get_record_timestamp_struct(0);
+                               if (sar_get_record_timestamp_struct(0))
+                                       /*
+                                        * An error was detected.
+                                        * The timestamp hasn't been updated.
+                                        */
+                                       continue;
                        }
                }
                while ((rtype == R_RESTART) || (rtype == R_COMMENT) ||