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=-19.4 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 57D53C43462 for ; Mon, 10 May 2021 10:56:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3C3BD6147D for ; Mon, 10 May 2021 10:56:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233281AbhEJKyd (ORCPT ); Mon, 10 May 2021 06:54:33 -0400 Received: from mail.kernel.org ([198.145.29.99]:57348 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231640AbhEJKnO (ORCPT ); Mon, 10 May 2021 06:43:14 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 6300161982; Mon, 10 May 2021 10:32:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1620642775; bh=HJQU5DyvW9xduhipoOniHRMWuWAwWg7D4AkVdwbJluA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=H8TAHwP6GDYIkoeE9ey7TKvYNvzWL/fz3p6KnHlhbzOc54DNE5OV0AVOvJOKHDA4g Nx7Xij2SwL0/09Vw6daHEedZfBpA2iG+ciSkG4JFAaJ6uQD0rtRzqD0MfQiQryo6fb ycTNPrJbJflKm+enTAxRCY3+pQFlaVg4fE/849yM= 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 5.10 011/299] ACPI: custom_method: fix a possible memory leak Date: Mon, 10 May 2021 12:16:48 +0200 Message-Id: <20210510102005.212191743@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210510102004.821838356@linuxfoundation.org> References: <20210510102004.821838356@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 @@ -42,6 +42,8 @@ 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;