From: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Date: Fri, 20 Dec 2019 06:39:17 +0000 (-0500)
Subject: Fix: lttng-clear: invalid free of session name
X-Git-Tag: v2.12.0-rc1~88
X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=commitdiff_plain;h=8539125677fb0761db1fa2e4b2118eddd5765868

Fix: lttng-clear: invalid free of session name

Valgrind reports an invalid free of session_name when it is sourced
from the popt args. Only free it when it comes from the .lttngrc file.

This also caused spurious core dumps when running the tests on
one of my machines.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I194cd36147a1028aad503b4e5d3ea23732a30bc5
---

diff --git a/src/bin/lttng/commands/clear.c b/src/bin/lttng/commands/clear.c
index 353c855c6..24db9f37e 100644
--- a/src/bin/lttng/commands/clear.c
+++ b/src/bin/lttng/commands/clear.c
@@ -168,7 +168,7 @@ int cmd_clear(int argc, const char **argv)
 	static poptContext pc;
 	char *session_name = NULL;
 	const char *leftover = NULL;
-
+	bool free_session_name = false;
 	struct lttng_session *sessions = NULL;
 	int count;
 	int found;
@@ -224,13 +224,7 @@ int cmd_clear(int argc, const char **argv)
 	}
 
 	if (!opt_clear_all) {
-		/*
-		 * popt expects us to free this even if it returns a const char *.
-		 * See https://www.mail-archive.com/popt-devel@rpm5.org/msg00193.html
-		 * Force cast to char * allowing later freeing if necessary.
-		 */
 		session_name = (char *) poptGetArg(pc);
-
 		if (!session_name) {
 			/* No session name specified, lookup default */
 			session_name = get_session_name();
@@ -239,6 +233,7 @@ int cmd_clear(int argc, const char **argv)
 				success = 0;
 				goto mi_closing;
 			}
+			free_session_name = true;
 		}
 	} else {
 		session_name = NULL;
@@ -323,7 +318,9 @@ end:
 	}
 
 	free(sessions);
-	free(session_name);
+	if (free_session_name) {
+		free(session_name);
+	}
 
 	/* Overwrite ret if an error occurred during clear_session/all */
 	ret = command_ret ? command_ret : ret;