[tip:perf/core] perf tools: Free temporary 'sys' string in read_event_files()

[tip-bot for Sanskriti Sharma]

Commit-ID:  1e44224fb0528b4c0cc176bde2bb31e9127eb14b
Gitweb:     https://git.kernel.org/tip/1e44224fb0528b4c0cc176bde2bb31e9127eb14b
Author:     Sanskriti Sharma <sansharm@xxxxxxxxxx>
AuthorDate: Tue, 2 Oct 2018 10:29:14 -0400
Committer:  Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Mon, 8 Oct 2018 14:23:46 -0300

perf tools: Free temporary 'sys' string in read_event_files()

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>
---
 tools/perf/util/trace-event-read.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/trace-event-read.c b/tools/perf/util/trace-event-read.c
index a278e1eee5f5..add8441de579 100644
--- a/tools/perf/util/trace-event-read.c
+++ b/tools/perf/util/trace-event-read.c
@@ -347,9 +347,12 @@ static int read_event_files(struct tep_handle *pevent)
 		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;
 }