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,USER_AGENT_GIT autolearn=unavailable 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 7A6A7C43381 for ; Mon, 18 Feb 2019 14:45:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4A30B2070B for ; Mon, 18 Feb 2019 14:45:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1550501142; bh=zHKRGemVqvcZi2+NoR3AImf85XUtOiLFTm3dc3/RK4I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=mrAdKoSRGFuMpxrs8iQAgAxf3bPXbY2I8+VX0i6hAqPMtwSQB8DDheuermUfTdb1B d+o2Y4ponjCz/PFttg3Ad3XXRdKKtesx3z6OvhkwOE65C4kHzxRo/CaFymt+FOOe6L HFUOKM3YSLOMucrsPBALhlV/t8qSNJlr/5jgubZ4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730605AbfBRNrY (ORCPT ); Mon, 18 Feb 2019 08:47:24 -0500 Received: from mail.kernel.org ([198.145.29.99]:53984 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730945AbfBRNrX (ORCPT ); Mon, 18 Feb 2019 08:47:23 -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 C46B2218FC; Mon, 18 Feb 2019 13:47:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1550497642; bh=zHKRGemVqvcZi2+NoR3AImf85XUtOiLFTm3dc3/RK4I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gOFVQdbwqTdhsGZoe/z0ASEeIX1hCQuM9THsUsFA4+VQG/2GtvVzxPSF64W6VZ0if ZphwCzL0fUPWgZXGIQFthkUQt1tj1hxkh+52/m9CMDudui7m0hWo9+YRWrqrG9ZaxS gF716oNaKVC7R2KNWU5NcwwP2PMG8PzQI043BRHg= 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 4.20 41/92] cifs: Limit memory used by lock request calls to a page Date: Mon, 18 Feb 2019 14:42:44 +0100 Message-Id: <20190218133458.550361264@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190218133454.668268457@linuxfoundation.org> References: <20190218133454.668268457@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: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 4.20-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 8431854b129f..116f8af0384f 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -1139,6 +1139,10 @@ 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); @@ -1477,6 +1481,10 @@ 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 2fc3d31967ee..b204e84b87fb 100644 --- a/fs/cifs/smb2file.c +++ b/fs/cifs/smb2file.c @@ -128,6 +128,8 @@ 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) @@ -264,6 +266,8 @@ 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