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>
This commit is contained in:
Miklos Szeredi 2021-08-06 10:03:12 +02:00 committed by AuxXxilium
parent c6064ee6c2
commit 6351f7eea0

View File

@ -390,6 +390,7 @@ 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;
@ -404,7 +405,6 @@ static struct dentry *ovl_lookup_real_one(struct dentry *connected,
}
out:
release_dentry_name_snapshot(&name);
dput(parent);
inode_unlock(dir);
return this;