damon/sysfs: fix possible memleak on damon_sysfs_add_target

From: Levi Yun <[email protected]>

When damon_sysfs_add_target couldn't find proper task, newly allocated damon_target structure isn't registered yet. So, it's impossible to free the newly allocated one by damon_sysfs_destroy_targets.

By calling damon_add_target as soon as allocating new target, fix this possible memory leak.

---

Changes from v4
(https://lore.kernel.org/damon/[email protected]/_
- Fix some typos

Changes from v3
(https://lore.kernel.org/damon/[email protected]/)
- Fix Fixes: tag
- Add patch changelog

Changes from v2
(https://lore.kernel.org/damon/[email protected]/)
- Add Fixes: and Cc: stable

Changes from v1
(https://lore.kernel.org/damon/[email protected]/)
- Do damon_add_target() earlier instead of explicitly freeing the object

 mm/damon/sysfs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index 455215a5c059..9f1219a67e3f 100644
@@ -2172,12 +2172,12 @@ static int damon_sysfs_add_target(struct damon_sysfs_target *sys_target,
 
 	if (!t)
 		return -ENOMEM;
+	damon_add_target(ctx, t);
 	if (damon_target_has_pid(ctx)) {
 		t->pid = find_get_pid(sys_target->pid);
 		if (!t->pid)
 			goto destroy_targets_out;
 	}
-	damon_add_target(ctx, t);
 	err = damon_sysfs_set_regions(t, sys_target->regions);
 	if (err)
 		goto destroy_targets_out;

2.25.1