[PATCH urgent] perf data: Fix double free in perf_session__delete

From: Alexey Bayduraev
Date: Fri Feb 18 2022 - 10:23:55 EST


When perf_data__create_dir fails, it calls close_dir, but
perf_session__delete also calls close_dir and since dir.version and
dir.nr was initialized by perf_data__create_dir, a double free occurs.
This patch moves the initialization of dir.version and dir.nr after
successful initialization of dir.files, that prevents double freeing.
This behavior is already implemented in perf_data__open_dir.

Fixes: 145520631130bd64 ("perf data: Add perf_data__(create_dir|close_dir) functions")
Signed-off-by: Alexey Bayduraev <alexey.v.bayduraev@xxxxxxxxxxxxxxx>
---
tools/perf/util/data.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/tools/perf/util/data.c b/tools/perf/util/data.c
index f5d260b1df4d..15a4547d608e 100644
--- a/tools/perf/util/data.c
+++ b/tools/perf/util/data.c
@@ -44,10 +44,6 @@ int perf_data__create_dir(struct perf_data *data, int nr)
if (!files)
return -ENOMEM;

- data->dir.version = PERF_DIR_VERSION;
- data->dir.files = files;
- data->dir.nr = nr;
-
for (i = 0; i < nr; i++) {
struct perf_data_file *file = &files[i];

@@ -62,6 +58,9 @@ int perf_data__create_dir(struct perf_data *data, int nr)
file->fd = ret;
}

+ data->dir.version = PERF_DIR_VERSION;
+ data->dir.files = files;
+ data->dir.nr = nr;
return 0;

out_err:
--
2.19.0