From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Namjae Jeon <linkinjeon@kernel.org>,
        Christophe JAILLET <christophe.jaillet@wanadoo.fr>,
        Steve French <stfrench@microsoft.com>
Subject: [PATCH 5.15 169/179] ksmbd: Fix an error handling path in smb2_sess_setup()
Date:   Mon, 29 Nov 2021 19:19:23 +0100
Message-Id: <20211129181724.491431873@linuxfoundation.org>
In-Reply-To: <20211129181718.913038547@linuxfoundation.org>
References: <20211129181718.913038547@linuxfoundation.org>
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From: Christophe JAILLET <christophe.jaillet@wanadoo.fr>

commit f8fbfd85f5c95fff477a7c19f576725945891d0c upstream.

All the error handling paths of 'smb2_sess_setup()' end to 'out_err'.

All but the new error handling path added by the commit given in the Fixes
tag below.

Fix this error handling path and branch to 'out_err' as well.

Fixes: 0d994cd482ee ("ksmbd: add buffer validation in session setup")
Cc: stable@vger.kernel.org # v5.15
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 fs/ksmbd/smb2pdu.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

--- a/fs/ksmbd/smb2pdu.c
+++ b/fs/ksmbd/smb2pdu.c
@@ -1700,8 +1700,10 @@ int smb2_sess_setup(struct ksmbd_work *w
 	negblob_off = le16_to_cpu(req->SecurityBufferOffset);
 	negblob_len = le16_to_cpu(req->SecurityBufferLength);
 	if (negblob_off < (offsetof(struct smb2_sess_setup_req, Buffer) - 4) ||
-	    negblob_len < offsetof(struct negotiate_message, NegotiateFlags))
-		return -EINVAL;
+	    negblob_len < offsetof(struct negotiate_message, NegotiateFlags)) {
+		rc = -EINVAL;
+		goto out_err;
+	}
 
 	negblob = (struct negotiate_message *)((char *)&req->hdr.ProtocolId +
 			negblob_off);