From patchwork Mon May 10 10:16:45 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 433884 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=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 3B2F0C41538 for ; Mon, 10 May 2021 11:00:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F3FCE61998 for ; Mon, 10 May 2021 11:00:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235123AbhEJLAG (ORCPT ); Mon, 10 May 2021 07:00:06 -0400 Received: from mail.kernel.org ([198.145.29.99]:53030 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234111AbhEJKzy (ORCPT ); Mon, 10 May 2021 06:55:54 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 337746188B; Mon, 10 May 2021 10:43:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1620643436; bh=HJQU5DyvW9xduhipoOniHRMWuWAwWg7D4AkVdwbJluA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=yUAcoG/ZGq8QL8g2Xm5swYt1a5oMAdWR+c7mqlPYGv25lAuf/PFfjgcNOrXSEmdQw XsFYPbnzGDSKIvep/EOhfFIFnsQz7+g8aHIAV3zfd8LUJ9OBGkmtFXQD0d3K1ltrl+ DP0gBkBbeLGTS7G2NhLoOJ0Brry6WMEFjj8lE18Y= 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 5.11 015/342] ACPI: custom_method: fix a possible memory leak Date: Mon, 10 May 2021 12:16:45 +0200 Message-Id: <20210510102010.608533560@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210510102010.096403571@linuxfoundation.org> References: <20210510102010.096403571@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@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;