From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E8E2CC3A5A3 for ; Tue, 27 Aug 2019 08:03:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BBF5E20828 for ; Tue, 27 Aug 2019 08:03:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566892982; bh=BQJJ7V0TFi5l6Xs2+GGf5LTmUXearB8vYzqzeyd7hmU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=B3GRgJS6RbVdpi7DW6b7APac6/8APSmf6mpQQLJ5aWao4NZ2FaTXNSWnwsKZh2Sz/ q0Z4ZbRNDrYnAnjzqPU+PbNbutySFWcLI60mEiClxrY2phw7SN3ARU4aqysBbEWs5s V2sDnP+O8bG2ma1p6KbJN4A3sk9EgpT7kuILstp8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730862AbfH0IDB (ORCPT ); Tue, 27 Aug 2019 04:03:01 -0400 Received: from mail.kernel.org ([198.145.29.99]:60254 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732105AbfH0IC5 (ORCPT ); Tue, 27 Aug 2019 04:02:57 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 826D6206BA; Tue, 27 Aug 2019 08:02:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566892977; bh=BQJJ7V0TFi5l6Xs2+GGf5LTmUXearB8vYzqzeyd7hmU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UgHkAb/QoqHDdHGp7HQU3OJ3wXx7wCIWjxMg4+zenLeGrJ9G3Gp/kuWIDVx8xkt+A NxSzRH5lLqYfOC0SDLm7jSCCEOH8i/wFMIqvDuf2OVpY5lZ2k1aDkuCpR+iv/xjr5X HZXnSYxhRnS7viX6MVlVDHv4HLfyHy1iLhRxAGjM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Pavel Shilovsky , Ronnie Sahlberg , Steve French , Sasha Levin Subject: [PATCH 5.2 080/162] SMB3: Fix potential memory leak when processing compound chain Date: Tue, 27 Aug 2019 09:50:08 +0200 Message-Id: <20190827072740.898571657@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20190827072738.093683223@linuxfoundation.org> References: <20190827072738.093683223@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [ Upstream commit 3edeb4a4146dc3b54d6fa71b7ee0585cb52ebfdf ] When a reconnect happens in the middle of processing a compound chain the code leaks a buffer from the memory pool. Fix this by properly checking for a return code and freeing buffers in case of error. Also maintain a buf variable to be equal to either smallbuf or bigbuf depending on a response buffer size while parsing a chain and when returning to the caller. Signed-off-by: Pavel Shilovsky Reviewed-by: Ronnie Sahlberg Signed-off-by: Steve French Signed-off-by: Sasha Levin --- fs/cifs/smb2ops.c | 29 +++++++++++++++++------------ 1 file changed, 17 insertions(+), 12 deletions(-) diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c index 2ec37dc589a7b..ae10d6e297c3a 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -4015,7 +4015,6 @@ receive_encrypted_standard(struct TCP_Server_Info *server, { int ret, length; char *buf = server->smallbuf; - char *tmpbuf; struct smb2_sync_hdr *shdr; unsigned int pdu_length = server->pdu_size; unsigned int buf_size; @@ -4045,18 +4044,15 @@ receive_encrypted_standard(struct TCP_Server_Info *server, return length; next_is_large = server->large_buf; - one_more: +one_more: shdr = (struct smb2_sync_hdr *)buf; if (shdr->NextCommand) { - if (next_is_large) { - tmpbuf = server->bigbuf; + if (next_is_large) next_buffer = (char *)cifs_buf_get(); - } else { - tmpbuf = server->smallbuf; + else next_buffer = (char *)cifs_small_buf_get(); - } memcpy(next_buffer, - tmpbuf + le32_to_cpu(shdr->NextCommand), + buf + le32_to_cpu(shdr->NextCommand), pdu_length - le32_to_cpu(shdr->NextCommand)); } @@ -4085,12 +4081,21 @@ receive_encrypted_standard(struct TCP_Server_Info *server, pdu_length -= le32_to_cpu(shdr->NextCommand); server->large_buf = next_is_large; if (next_is_large) - server->bigbuf = next_buffer; + server->bigbuf = buf = next_buffer; else - server->smallbuf = next_buffer; - - buf += le32_to_cpu(shdr->NextCommand); + server->smallbuf = buf = next_buffer; goto one_more; + } else if (ret != 0) { + /* + * ret != 0 here means that we didn't get to handle_mid() thus + * server->smallbuf and server->bigbuf are still valid. We need + * to free next_buffer because it is not going to be used + * anywhere. + */ + if (next_is_large) + free_rsp_buf(CIFS_LARGE_BUFFER, next_buffer); + else + free_rsp_buf(CIFS_SMALL_BUFFER, next_buffer); } return ret; -- 2.20.1