[v2,42/87] trace-cmd library: Fix possible memory leak in read_and_parse_cmdlines()

Commit Message

Tzvetomir Stoyanov (VMware) July 29, 2021, 5:09 a.m. UTC

Some error paths in read_and_parse_cmdlines() may lead to a memory leak.
Improved the error handling of this internal function to avoid it.

Signed-off-by: Tzvetomir Stoyanov (VMware) <[e-mail]>
---
 lib/trace-cmd/trace-input.c | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

Patch

diff --git a/lib/trace-cmd/trace-input.c b/lib/trace-cmd/trace-input.c
index 5557e772..4324259a 100644
--- a/lib/trace-cmd/trace-input.c
+++ b/lib/trace-cmd/trace-input.c
@@ -3122,7 +3122,8 @@  static int read_and_parse_cmdlines(struct tracecmd_input *handle)
 {
 	struct tep_handle *pevent = handle->pevent;
 	unsigned long long size;
-	char *cmdlines;
+	char *cmdlines = NULL;
+	int ret;
 
 	if (CHECK_READ_STATE(handle, TRACECMD_FILE_CMD_LINES))
 		return 0;
@@ -3131,15 +3132,20 @@  static int read_and_parse_cmdlines(struct tracecmd_input *handle)
 		add_section(handle, TRACECMD_OPTION_CMDLINES, 0, 0,
 			    lseek64(handle->fd, 0, SEEK_CUR));
 
-	if (read_data_and_size(handle, &cmdlines, &size) < 0)
-		return -1;
+	ret = read_data_and_size(handle, &cmdlines, &size);
+	if (ret < 0)
+		goto out;
+	if (!size) {
+		handle->file_state = TRACECMD_FILE_CMD_LINES;
+		goto out;
+	}
 	cmdlines[size] = 0;
 	tep_parse_saved_cmdlines(pevent, cmdlines);
-	free(cmdlines);
-
 	handle->file_state = TRACECMD_FILE_CMD_LINES;
-
-	return 0;
+	ret = 0;
+out:
+	free(cmdlines);
+	return ret;
 }
 
 static void extract_trace_clock(struct tracecmd_input *handle, char *line)