From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 448B3171A9 for ; Mon, 22 May 2023 19:34:45 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B53DEC433EF; Mon, 22 May 2023 19:34:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1684784085; bh=muPfp96Y8jPOu5ifnD9zPB/uMweMgjCkJ+tUqh41FQo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=z/RXf3t7iGLoEtFXhhKdu+2yvG6BfAOoBL+Eg87qnetB0IG0QAWvcA9/6aXHFdkA8 LcFyyLfej4+zAUpDFvF0bOGheWD4/o/9/OqlSLHTtGElSDqRP1QdyegjvczyfWGsMt xulpCxcUx3MQhCpJnFF6qlxOa8hzJn+7GhrUn5Ls= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Chih-Yen Chang , Namjae Jeon , Steve French Subject: [PATCH 6.1 258/292] ksmbd: fix wrong UserName check in session_user Date: Mon, 22 May 2023 20:10:15 +0100 Message-Id: <20230522190412.392181636@linuxfoundation.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230522190405.880733338@linuxfoundation.org> References: <20230522190405.880733338@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Chih-Yen Chang commit f0a96d1aafd8964e1f9955c830a3e5cb3c60a90f upstream. The offset of UserName is related to the address of security buffer. To ensure the validaty of UserName, we need to compare name_off + name_len with secbuf_len instead of auth_msg_len. [ 27.096243] ================================================================== [ 27.096890] BUG: KASAN: slab-out-of-bounds in smb_strndup_from_utf16+0x188/0x350 [ 27.097609] Read of size 2 at addr ffff888005e3b542 by task kworker/0:0/7 ... [ 27.099950] Call Trace: [ 27.100194] [ 27.100397] dump_stack_lvl+0x33/0x50 [ 27.100752] print_report+0xcc/0x620 [ 27.102305] kasan_report+0xae/0xe0 [ 27.103072] kasan_check_range+0x35/0x1b0 [ 27.103757] smb_strndup_from_utf16+0x188/0x350 [ 27.105474] smb2_sess_setup+0xaf8/0x19c0 [ 27.107935] handle_ksmbd_work+0x274/0x810 [ 27.108315] process_one_work+0x419/0x760 [ 27.108689] worker_thread+0x2a2/0x6f0 [ 27.109385] kthread+0x160/0x190 [ 27.110129] ret_from_fork+0x1f/0x30 [ 27.110454] Cc: stable@vger.kernel.org Signed-off-by: Chih-Yen Chang Acked-by: Namjae Jeon Signed-off-by: Steve French Signed-off-by: Greg Kroah-Hartman --- fs/ksmbd/smb2pdu.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) --- a/fs/ksmbd/smb2pdu.c +++ b/fs/ksmbd/smb2pdu.c @@ -1373,7 +1373,7 @@ static struct ksmbd_user *session_user(s struct authenticate_message *authblob; struct ksmbd_user *user; char *name; - unsigned int auth_msg_len, name_off, name_len, secbuf_len; + unsigned int name_off, name_len, secbuf_len; secbuf_len = le16_to_cpu(req->SecurityBufferLength); if (secbuf_len < sizeof(struct authenticate_message)) { @@ -1383,9 +1383,8 @@ static struct ksmbd_user *session_user(s authblob = user_authblob(conn, req); name_off = le32_to_cpu(authblob->UserName.BufferOffset); name_len = le16_to_cpu(authblob->UserName.Length); - auth_msg_len = le16_to_cpu(req->SecurityBufferOffset) + secbuf_len; - if (auth_msg_len < (u64)name_off + name_len) + if (secbuf_len < (u64)name_off + name_len) return NULL; name = smb_strndup_from_utf16((const char *)authblob + name_off,