File s390-tools-sles15-mon_procd-fix-parsing-of-proc-pid-stat.patch of Package s390-tools.10760

Subject: mon_procd: fix parsing of /proc/<pid>/stat
From: Gerald Schaefer <gerald.schaefer@de.ibm.com>

Description:  mon_procd: fix parsing of /proc/<pid>/stat
Symptom:      Wrong data from /proc/<pid>/stat for processes that contain
              a ")" in their name.
Problem:      The output of /proc/<pid>/stat will show the process name in
              parentheses. The parsing code in read_stat() tries to filter
              out the parentheses, which will go wrong when the process name
              itself also contains parentheses, e.g. in an output like this:
              "2421 ((sd-pam)) S 2420 2420 2420 ..."
              In this case, the first closing parentheses will be taken as
              end marker, and the sscanf() on the remaining string will
              silently fail, leaving its values in uninitialized state and
              producing wrong data.
Solution:     Use strrchr() instead of strchr() to find the last closing
              parentheses. Also add return value checking for sscanf() and
              initialize the values to 0.
Reproduction: Use mon_procd on a system with running processes that have a
              ")" in their name, like "(sd-pam)".
Upstream-ID:  -
Problem-ID:   169483

Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
---
 mon_tools/mon_procd.c |   13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

--- a/mon_tools/mon_procd.c
+++ b/mon_tools/mon_procd.c
@@ -594,17 +594,18 @@ static void cal_task_pcpu(struct task_t
 */
 static int read_stat(struct task_t *task)
 {
-	int ppid, tty, proc;
-	unsigned long flags, pri, nice;
-	unsigned long long maj_flt, utime, stime, cutime, cstime;
+	unsigned long long maj_flt = 0, utime = 0, stime = 0, cutime = 0,
+			   cstime = 0;
+	unsigned long flags = 0, pri = 0, nice = 0;
 	char *cmd_start, *cmd_end, *cmdlenp, *cmdp;
+	int ppid = 0, tty = 0, proc = 0, rc;
 
 	snprintf(fname, sizeof(fname), "/proc/%u/stat", task->pid);
 	if (read_file(fname, buf, sizeof(buf) - 1) == -1)
 		return 0;
 
 	cmd_start = strchr(buf, '(') + 1;
-	cmd_end = strchr(cmd_start, ')');
+	cmd_end = strrchr(cmd_start, ')');
 	name_lens.cmd_len = cmd_end - cmd_start;
 	cmdlenp = mon_record + sizeof(struct monwrite_hdr);
 	cmdlenp += sizeof(struct procd_hdr);
@@ -625,7 +626,7 @@ static int read_stat(struct task_t *task
 	memcpy(cmdlenp, &name_lens.cmd_len, sizeof(__u16));
 
 	cmd_end += 2;
-	sscanf(cmd_end,
+	rc = sscanf(cmd_end,
 		"%c %d %*d %*d %d %*d "
 		"%lu %*s %*s %Lu %*s "
 		"%Lu %Lu %Lu %Lu "
@@ -642,6 +643,8 @@ static int read_stat(struct task_t *task
 		&utime, &stime, &cutime, &cstime,
 		&pri, &nice,
 		&proc);
+	if (rc != 12)
+		syslog(LOG_ERR, "bad data in %s \n", fname);
 	task->ppid = (__u32)ppid;
 	task->tty = (__u16)tty;
 	task->flags = (__u32)flags;