[PATCH for-stable-5.19.y] fix possible memleak on damon_sysfs_add_target

[PATCH for-stable-5.19.y] fix possible memleak on damon_sysfs_add_target

[Levi Yun]

commit 1c8e2349f2d0 ("damon/sysfs: fix possible memleak on damon_sysfs_add_target") upstream.

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: a61ea561c871 ("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> # 5.19.x
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
 mm/damon/sysfs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/damon/sysfs.c b/mm/damon/sysfs.c
index 09f9e8ca3d1f..5b5ee3308d71 100644
--- a/mm/damon/sysfs.c
+++ b/mm/damon/sysfs.c
@@ -2181,13 +2181,13 @@ static int damon_sysfs_add_target(struct damon_sysfs_target *sys_target,

 	if (!t)
 		return -ENOMEM;
+	damon_add_target(ctx, t);
 	if (ctx->ops.id == DAMON_OPS_VADDR ||
 			ctx->ops.id == DAMON_OPS_FVADDR) {
 		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;
--
2.35.1

Re: [PATCH for-stable-5.19.y] fix possible memleak on damon_sysfs_add_target

[Greg KH]

On Mon, Oct 03, 2022 at 07:54:45AM +0900, Levi Yun wrote:
> commit 1c8e2349f2d0 ("damon/sysfs: fix possible memleak on damon_sysfs_add_target") upstream.

Now queued up, thanks,

greg k-h