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 3c6e2b3f0d641d2182223614b1e20de526827b16..ce0e83ec7dfe5bef3c48fd8383e3f2d9fa7e1d71 100644 (file)
--- 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) {