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=-19.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,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 33C28C433B4 for ; Thu, 20 May 2021 11:26:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1AABD6024A for ; Thu, 20 May 2021 11:26:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241594AbhETL1g (ORCPT ); Thu, 20 May 2021 07:27:36 -0400 Received: from mail.kernel.org ([198.145.29.99]:38974 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238049AbhETLHr (ORCPT ); Thu, 20 May 2021 07:07:47 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 3249860BD3; Thu, 20 May 2021 10:06:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1621505161; bh=ElMWXytHLhIqi64Gk7kpZGsahtsBL1G92TPQA90NMtY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=evB4a6AbNpoS852uS1hscBgQaxd8ZrSSqYnl0XF785RwVtUL63TOIrRwF9652XP5q 3F46vgdOeyLIHb8qyG2/htc7r/n3GRSCxSvX5cyTYEowznoVETUt6UIWiyJIel+hx5 k6qdD/ePyIugUeHwllCbSy98tKWbRRNBB6Jz86Uw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mark Langsdorf , "Rafael J. Wysocki" Subject: [PATCH 4.4 010/190] ACPI: custom_method: fix a possible memory leak Date: Thu, 20 May 2021 11:21:14 +0200 Message-Id: <20210520092102.518366034@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210520092102.149300807@linuxfoundation.org> References: <20210520092102.149300807@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Mark Langsdorf commit 1cfd8956437f842836e8a066b40d1ec2fc01f13e upstream. In cm_write(), if the 'buf' is allocated memory but not fully consumed, it is possible to reallocate the buffer without freeing it by passing '*ppos' as 0 on a subsequent call. Add an explicit kfree() before kzalloc() to prevent the possible memory leak. Fixes: 526b4af47f44 ("ACPI: Split out custom_method functionality into an own driver") Signed-off-by: Mark Langsdorf Cc: 5.4+ # 5.4+ Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman --- drivers/acpi/custom_method.c | 2 ++ 1 file changed, 2 insertions(+) --- a/drivers/acpi/custom_method.c +++ b/drivers/acpi/custom_method.c @@ -37,6 +37,8 @@ static ssize_t cm_write(struct file *fil sizeof(struct acpi_table_header))) return -EFAULT; uncopied_bytes = max_size = table.length; + /* make sure the buf is not allocated */ + kfree(buf); buf = kzalloc(max_size, GFP_KERNEL); if (!buf) return -ENOMEM;