use-after-free
==============
The following functions are affected:
`lttng_event_expr_app_specific_context_field_create()`, and
`lttng_event_expr_array_field_element_create()`.
In one error path we call `lttng_event_expr_destroy()` with the
`&expr->parent` pointer (which is dynamically allocated) and this
function then calls free() on that pointer. Right after that function
call we return the pointer that was just freed.
Fix that by adding a `ret_parent_expr` pointer that is set to NULL on
the error path;
Null pointer dereference
========================
The following functions are affected:
`lttng_event_expr_app_specific_context_field_create()`,
`lttng_event_expr_array_field_element_create()`, and
`create_field_event_expr()`.
We dereference a NULL pointer if the argument sanity check fails.
Fix that by checking if `expr` is non-null before dereferencing it.
Found with scan-build.
Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I5fdde462d7345d0dae7ecd2e4f46473a92cd11a9
- lttng_event_expr_destroy(&expr->parent);
+ if (expr) {
+ lttng_event_expr_destroy(&expr->parent);
+ }
+ expr = NULL;
const char *provider_name, const char *type_name)
{
struct lttng_event_expr_app_specific_context_field *expr = NULL;
const char *provider_name, const char *type_name)
{
struct lttng_event_expr_app_specific_context_field *expr = NULL;
+ struct lttng_event_expr *ret_parent_expr;
if (!type_name || !provider_name) {
goto error;
if (!type_name || !provider_name) {
goto error;
+ ret_parent_expr = &expr->parent;
- lttng_event_expr_destroy(&expr->parent);
+ if (expr) {
+ lttng_event_expr_destroy(&expr->parent);
+ }
+ ret_parent_expr = NULL;
+ return ret_parent_expr;
}
struct lttng_event_expr *lttng_event_expr_array_field_element_create(
}
struct lttng_event_expr *lttng_event_expr_array_field_element_create(
unsigned int index)
{
struct lttng_event_expr_array_field_element *expr = NULL;
unsigned int index)
{
struct lttng_event_expr_array_field_element *expr = NULL;
+ struct lttng_event_expr *ret_parent_expr;
/* The parent array field expression must be an l-value */
if (!array_field_expr ||
/* The parent array field expression must be an l-value */
if (!array_field_expr ||
expr->array_field_expr = array_field_expr;
expr->index = index;
expr->array_field_expr = array_field_expr;
expr->index = index;
+ ret_parent_expr = &expr->parent;
- lttng_event_expr_destroy(&expr->parent);
+ if (expr) {
+ lttng_event_expr_destroy(&expr->parent);
+ }
+ ret_parent_expr = NULL;
+ return ret_parent_expr;
}
const char *lttng_event_expr_event_payload_field_get_name(
}
const char *lttng_event_expr_event_payload_field_get_name(