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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 52793C32750 for ; Wed, 14 Aug 2019 02:17:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2A34B208C2 for ; Wed, 14 Aug 2019 02:17:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1565749031; bh=I+Et8CHLaDHb5aVf7jBfwWjMAQP/TDM5XArmZyBJHiA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Wi655VinOqd9erLLVRCtk3UG5+sUgnXTyqmg/uE4xN7YYVKeQYBMwGt1lGy5bYKnP U11PtjD20EjFp00e6j4ICqZc4zItJMuIw0DYccB1aD2SGXv80pt3W/qBG2znW/U1ec qgmyl4MB4DO0Mlk8fhkISQpXKQ7kmc40Uzt4ElHQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729306AbfHNCRK (ORCPT ); Tue, 13 Aug 2019 22:17:10 -0400 Received: from mail.kernel.org ([198.145.29.99]:48508 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727804AbfHNCRJ (ORCPT ); Tue, 13 Aug 2019 22:17:09 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id BE021208C2; Wed, 14 Aug 2019 02:17:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1565749028; bh=I+Et8CHLaDHb5aVf7jBfwWjMAQP/TDM5XArmZyBJHiA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TCSmyQhHTutR1NAlh2ukJxUmwySfUv2zCNIVweA5/Cxn8MF0XPwFoHobpet53Wd/K jmT7u0TJjLXyjsFzcnuFnrRefkJqdOYowP/uZHAISz3oC1AE2/BVuwRGmZNkubW5sY 9tFfMvXHQtWZQCpNvrxofiZezlV3mQDhwQLe/teM= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Pavel Shilovsky , Ronnie Sahlberg , Steve French , Sasha Levin , linux-cifs@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 46/68] SMB3: Fix potential memory leak when processing compound chain Date: Tue, 13 Aug 2019 22:15:24 -0400 Message-Id: <20190814021548.16001-46-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190814021548.16001-1-sashal@kernel.org> References: <20190814021548.16001-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-cifs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org From: Pavel Shilovsky [ 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 0ccf8f9b63a2e..97fdbec54db97 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -3121,7 +3121,6 @@ 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; @@ -3151,18 +3150,15 @@ 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)); } @@ -3191,12 +3187,21 @@ 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