Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org,
        syzbot+ff03fe05c717b82502d0@syzkaller.appspotmail.com,
        Amir Goldstein <amir73il@gmail.com>,
        Miklos Szeredi <mszeredi@redhat.com>
Subject: [PATCH 4.19 046/205] ovl: fix error handling in ovl_verify_set_fh()
Date:   Mon, 19 Nov 2018 17:25:53 +0100
Message-Id: <20181119162625.590450047@linuxfoundation.org>
In-Reply-To: <20181119162616.586062722@linuxfoundation.org>
References: <20181119162616.586062722@linuxfoundation.org>
User-Agent: quilt/0.65
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

4.19-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Amir Goldstein <amir73il@gmail.com>

commit babf4770be0adc69e6d2de150f4040f175e24beb upstream.

We hit a BUG on kfree of an ERR_PTR()...

Reported-by: syzbot+ff03fe05c717b82502d0@syzkaller.appspotmail.com
Fixes: 8b88a2e64036 ("ovl: verify upper root dir matches lower root dir")
Cc: <stable@vger.kernel.org> # v4.13
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 fs/overlayfs/namei.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/fs/overlayfs/namei.c
+++ b/fs/overlayfs/namei.c
@@ -422,8 +422,10 @@ int ovl_verify_set_fh(struct dentry *den
 
 	fh = ovl_encode_real_fh(real, is_upper);
 	err = PTR_ERR(fh);
-	if (IS_ERR(fh))
+	if (IS_ERR(fh)) {
+		fh = NULL;
 		goto fail;
+	}
 
 	err = ovl_verify_fh(dentry, name, fh);
 	if (set && err == -ENODATA)