[PATCH 4/5] perf tools: avoid double free in read_event_file()

From: Sanskriti Sharma
Date: Tue Oct 02 2018 - 10:29:49 EST


The temporary 'buf' buffer allocated in read_event_file() may be freed
twice. Move the free() call to the common function exit point.

Fixes the following coverity complaints:

Error: USE_AFTER_FREE (CWE-825):
tools/perf/util/trace-event-read.c:309: double_free: Calling "free"
frees pointer "buf" which has already been freed.

Signed-off-by: Sanskriti Sharma <sansharm@xxxxxxxxxx>
---
tools/perf/util/trace-event-read.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/tools/perf/util/trace-event-read.c b/tools/perf/util/trace-event-read.c
index 3dfc1db..6a0d0f2 100644
--- a/tools/perf/util/trace-event-read.c
+++ b/tools/perf/util/trace-event-read.c
@@ -297,10 +297,8 @@ static int read_event_file(struct tep_handle *pevent, char *sys,
}

ret = do_read(buf, size);
- if (ret < 0) {
- free(buf);
+ if (ret < 0)
goto out;
- }

ret = parse_event_file(pevent, buf, size, sys);
if (ret < 0)
--
1.8.3.1