From: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Date: Mon, 5 Jul 2021 18:21:19 +0000 (-0400)
Subject: Fix: lttng: remove-trigger: null dereference on MI initialization error
X-Git-Tag: v2.13.0-rc3~17
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=9ec21c2a12dc7db110ddc78b58078c7273129a81;p=lttng-tools.git

Fix: lttng: remove-trigger: null dereference on MI initialization error

Failures to create an MI writer instance will result in a dereference of
the MI writer when attempting to close the command's output element.

1457842 Dereference after null check

Either the check against null is unnecessary, or there may be a null
pointer dereference.

In cmd_add_trigger: Pointer is checked against null but then
dereferenced anyway (CWE-476)

Reported-by: Coverity Scan

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I0bc71bf6c83df7d9d938cf93a12d5f6cf6d7ae36
---

diff --git a/src/bin/lttng/commands/remove_trigger.c b/src/bin/lttng/commands/remove_trigger.c
index 3c6e2b3f0..ce0e83ec7 100644
--- a/src/bin/lttng/commands/remove_trigger.c
+++ b/src/bin/lttng/commands/remove_trigger.c
@@ -227,7 +227,7 @@ error:
 
 end:
 	/* Mi closing. */
-	if (lttng_opt_mi) {
+	if (lttng_opt_mi && mi_writer) {
 		/* Close output element. */
 		int mi_ret = mi_lttng_writer_close_element(mi_writer);
 		if (mi_ret) {