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=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,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 930D9C43381 for ; Mon, 18 Feb 2019 13:58:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 63B39217F9 for ; Mon, 18 Feb 2019 13:58:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1550498333; bh=okiAX8/GvgeHs96zqDcQhAP91OYi6LguLffJ11plJTQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Oqb6Fay02I1Cu9YgkDrsnYR+MBxrPHQrCCpcbWLotvDxIusWg2Tzu2A/HMQI7kcCD Rii5058AntJO2BtO7SKhBCzBiMf+Pzd2ZvaFN0U3JvXDHahbKLzGEK4QkZwsA4lGhx u+lmUSCyz+KPGvDA08TnQ+shZwrhmXM7Qa7RP+zM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388452AbfBRN6v (ORCPT ); Mon, 18 Feb 2019 08:58:51 -0500 Received: from mail.kernel.org ([198.145.29.99]:39564 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388428AbfBRN6r (ORCPT ); Mon, 18 Feb 2019 08:58:47 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.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 AA5AF21901; Mon, 18 Feb 2019 13:58:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1550498326; bh=okiAX8/GvgeHs96zqDcQhAP91OYi6LguLffJ11plJTQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=dJg/eWGTOf8EjmVgY6lRHmRoiQ+iMdqufWRv9z7XGJci2l01mBvYc0L4TFYqCNs/C NoJS26wWYDLZld0BoRN5FztYvjCQ+z/8nxq3cjDVxLhOqNOeP2sAsKQj9vAAy7m7yI utQk5wp/k4IuY9pWIJ7CPfhEOfC+Qdw7N+dviyZU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ross Lagerwall , Steve French , Sasha Levin Subject: [PATCH 4.9 33/58] cifs: Limit memory used by lock request calls to a page Date: Mon, 18 Feb 2019 14:43:54 +0100 Message-Id: <20190218133511.215363164@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190218133508.567416115@linuxfoundation.org> References: <20190218133508.567416115@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore 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 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ [ Upstream commit 92a8109e4d3a34fb6b115c9098b51767dc933444 ] The code tries to allocate a contiguous buffer with a size supplied by the server (maxBuf). This could fail if memory is fragmented since it results in high order allocations for commonly used server implementations. It is also wasteful since there are probably few locks in the usual case. Limit the buffer to be no larger than a page to avoid memory allocation failures due to fragmentation. Signed-off-by: Ross Lagerwall Signed-off-by: Steve French Signed-off-by: Sasha Levin --- fs/cifs/file.c | 8 ++++++++ fs/cifs/smb2file.c | 4 ++++ 2 files changed, 12 insertions(+) diff --git a/fs/cifs/file.c b/fs/cifs/file.c index a3046b6523c8..8ec296308729 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -1126,6 +1126,10 @@ cifs_push_mandatory_locks(struct cifsFileInfo *cfile) return -EINVAL; } + BUILD_BUG_ON(sizeof(struct smb_hdr) + sizeof(LOCKING_ANDX_RANGE) > + PAGE_SIZE); + max_buf = min_t(unsigned int, max_buf - sizeof(struct smb_hdr), + PAGE_SIZE); max_num = (max_buf - sizeof(struct smb_hdr)) / sizeof(LOCKING_ANDX_RANGE); buf = kcalloc(max_num, sizeof(LOCKING_ANDX_RANGE), GFP_KERNEL); @@ -1462,6 +1466,10 @@ cifs_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock, if (max_buf < (sizeof(struct smb_hdr) + sizeof(LOCKING_ANDX_RANGE))) return -EINVAL; + BUILD_BUG_ON(sizeof(struct smb_hdr) + sizeof(LOCKING_ANDX_RANGE) > + PAGE_SIZE); + max_buf = min_t(unsigned int, max_buf - sizeof(struct smb_hdr), + PAGE_SIZE); max_num = (max_buf - sizeof(struct smb_hdr)) / sizeof(LOCKING_ANDX_RANGE); buf = kcalloc(max_num, sizeof(LOCKING_ANDX_RANGE), GFP_KERNEL); diff --git a/fs/cifs/smb2file.c b/fs/cifs/smb2file.c index b7885dc0d9bb..dee5250701de 100644 --- a/fs/cifs/smb2file.c +++ b/fs/cifs/smb2file.c @@ -129,6 +129,8 @@ smb2_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock, if (max_buf < sizeof(struct smb2_lock_element)) return -EINVAL; + BUILD_BUG_ON(sizeof(struct smb2_lock_element) > PAGE_SIZE); + max_buf = min_t(unsigned int, max_buf, PAGE_SIZE); max_num = max_buf / sizeof(struct smb2_lock_element); buf = kcalloc(max_num, sizeof(struct smb2_lock_element), GFP_KERNEL); if (!buf) @@ -265,6 +267,8 @@ smb2_push_mandatory_locks(struct cifsFileInfo *cfile) return -EINVAL; } + BUILD_BUG_ON(sizeof(struct smb2_lock_element) > PAGE_SIZE); + max_buf = min_t(unsigned int, max_buf, PAGE_SIZE); max_num = max_buf / sizeof(struct smb2_lock_element); buf = kcalloc(max_num, sizeof(struct smb2_lock_element), GFP_KERNEL); if (!buf) { -- 2.19.1