[PATCH 4.4 020/160] perf tools: Free temporary sys string in read_event_files()

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Sanskriti Sharma <sansharm@xxxxxxxxxx>

[ Upstream commit 1e44224fb0528b4c0cc176bde2bb31e9127eb14b ]

For each system in a given pevent, read_event_files() reads in a
temporary 'sys' string.  Be sure to free this string before moving onto
to the next system and/or leaving read_event_files().

Fixes the following coverity complaints:

  Error: RESOURCE_LEAK (CWE-772):

  tools/perf/util/trace-event-read.c:343: overwrite_var: Overwriting
  "sys" in "sys = read_string()" leaks the storage that "sys" points to.

  tools/perf/util/trace-event-read.c:353: leaked_storage: Variable "sys"
  going out of scope leaks the storage it points to.

Signed-off-by: Sanskriti Sharma <sansharm@xxxxxxxxxx>
Reviewed-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Joe Lawrence <joe.lawrence@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/1538490554-8161-6-git-send-email-sansharm@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 tools/perf/util/trace-event-read.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

--- a/tools/perf/util/trace-event-read.c
+++ b/tools/perf/util/trace-event-read.c
@@ -334,9 +334,12 @@ static int read_event_files(struct peven
 		for (x=0; x < count; x++) {
 			size = read8(pevent);
 			ret = read_event_file(pevent, sys, size);
-			if (ret)
+			if (ret) {
+				free(sys);
 				return ret;
+			}
 		}
+		free(sys);
 	}
 	return 0;
 }