linux-unionfs.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Miklos Szeredi <mszeredi@redhat.com>,
	Colin Ian King <colin.king@canonical.com>,
	Sasha Levin <sashal@kernel.org>,
	linux-unionfs@vger.kernel.org
Subject: [PATCH AUTOSEL 5.10 8/9] ovl: fix uninitialized pointer read in ovl_lookup_real_one()
Date: Mon, 16 Aug 2021 20:35:53 -0400	[thread overview]
Message-ID: <20210817003554.83213-8-sashal@kernel.org> (raw)
In-Reply-To: <20210817003554.83213-1-sashal@kernel.org>

From: Miklos Szeredi <mszeredi@redhat.com>

[ 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>
---
 fs/overlayfs/export.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/overlayfs/export.c b/fs/overlayfs/export.c
index ed35be3fafc6..f469982dcb36 100644
--- a/fs/overlayfs/export.c
+++ b/fs/overlayfs/export.c
@@ -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;
-- 
2.30.2


           reply	other threads:[~2021-08-17  0:38 UTC|newest]

Thread overview: expand[flat|nested]  mbox.gz  Atom feed
 [parent not found: <20210817003554.83213-1-sashal@kernel.org>]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210817003554.83213-8-sashal@kernel.org \
    --to=sashal@kernel.org \
    --cc=colin.king@canonical.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-unionfs@vger.kernel.org \
    --cc=mszeredi@redhat.com \
    --cc=stable@vger.kernel.org \
    --subject='Re: [PATCH AUTOSEL 5.10 8/9] ovl: fix uninitialized pointer read in ovl_lookup_real_one()' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).