damon/sysfs: fix possible memleak on damon_sysfs_add_target

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

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

Link: https://lkml.kernel.org/r/20220926160611.48536-1-sj@kernel.org
Fixes: 29d07968b525 ("mm/damon/sysfs: link DAMON for virtual address spaces monitoring")
Signed-off-by: Levi Yun <ppbuk5246@gmail.com>
Signed-off-by: SeongJae Park <sj@kernel.org>
Reviewed-by: SeongJae Park <sj@kernel.org>
Cc: <stable@vger.kernel.org>	[5.17.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/damon/sysfs.c b/mm/damon/sysfs.c
index 7488e27c87c37748179134f0a5cecc5f7bb6d79f..bdef9682d0a00805c9e459b48cf535950bd18081 100644 (file)
--- a/mm/damon/sysfs.c
+++ b/mm/damon/sysfs.c
@@ -2182,12 +2182,12 @@ 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;