Commit aec1e470 authored Aug 06, 2021 by Miklos Szeredi Committed by Greg Kroah-Hartman Sep 03, 2021

ovl: fix uninitialized pointer read in ovl_lookup_real_one()



[ Upstream commit 580c610429b3994e8db24418927747cf28443cde ]

One error path can result in release_dentry_name_snapshot() being called
before "name" was initialized by take_dentry_name_snapshot().

Fix by moving the release_dentry_name_snapshot() to immediately after the
only use.

Reported-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent 57bd5b59

fs/overlayfs/export.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -395,6 +395,7 @@ static struct dentry ovl_lookup_real_one(struct dentry connected,
		*/
		take_dentry_name_snapshot(&name, real);
		this = lookup_one_len(name.name.name, connected, name.name.len);
		release_dentry_name_snapshot(&name);
		err = PTR_ERR(this);
		if (IS_ERR(this)) {
		goto fail;
		@@ -409,7 +410,6 @@ static struct dentry ovl_lookup_real_one(struct dentry connected,
		}

		out:
		release_dentry_name_snapshot(&name);
		dput(parent);
		inode_unlock(dir);
		return this;