Commit 1552fd3e authored by Greg Kroah-Hartman's avatar Greg Kroah-Hartman Committed by Andrew Morton
Browse files

mm/damon/dbgfs: fix memory leak when using debugfs_lookup() 

When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time.  Fix this up by properly calling
dput().

Link: https://lkml.kernel.org/r/20220902191149.112434-1-sj@kernel.org


Fixes: 75c1c2b5 ("mm/damon/dbgfs: support multiple contexts")
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarSeongJae Park <sj@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent fd35ca3d

mm/damon/dbgfs.c

+14 −5
Original line number Diff line number Diff line
@@ -884,6 +884,7 @@ static int dbgfs_rm_context(char *name) 
	struct dentry *root, *dir, **new_dirs;

	struct damon_ctx **new_ctxs;

	int i, j;

	int ret = 0;



	if (damon_nr_running_ctxs())

		return -EBUSY;
@@ -898,14 +899,16 @@ static int dbgfs_rm_context(char *name) 


	new_dirs = kmalloc_array(dbgfs_nr_ctxs - 1, sizeof(*dbgfs_dirs),

			GFP_KERNEL);

	if (!new_dirs)

		return -ENOMEM;

	if (!new_dirs) {

		ret = -ENOMEM;

		goto out_dput;

	}



	new_ctxs = kmalloc_array(dbgfs_nr_ctxs - 1, sizeof(*dbgfs_ctxs),

			GFP_KERNEL);

	if (!new_ctxs) {

		kfree(new_dirs);

		return -ENOMEM;

		ret = -ENOMEM;

		goto out_new_dirs;

	}



	for (i = 0, j = 0; i < dbgfs_nr_ctxs; i++) {
@@ -925,7 +928,13 @@ static int dbgfs_rm_context(char *name) 
	dbgfs_ctxs = new_ctxs;

	dbgfs_nr_ctxs--;



	return 0;

	goto out_dput;



out_new_dirs:

	kfree(new_dirs);

out_dput:

	dput(dir);

	return ret;

}



static ssize_t dbgfs_rm_context_write(struct file *file,