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=-18.8 required=3.0 tests=BAYES_00,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 82B1EC433FE for ; Thu, 16 Sep 2021 14:51:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5A2DB60EB6 for ; Thu, 16 Sep 2021 14:51:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238859AbhIPOxG (ORCPT ); Thu, 16 Sep 2021 10:53:06 -0400 Received: from smtp65.ord1d.emailsrvr.com ([184.106.54.65]:38121 "EHLO smtp65.ord1d.emailsrvr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230429AbhIPOxE (ORCPT ); Thu, 16 Sep 2021 10:53:04 -0400 X-Greylist: delayed 373 seconds by postgrey-1.27 at vger.kernel.org; Thu, 16 Sep 2021 10:53:04 EDT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=mev.co.uk; s=20190130-41we5z8j; t=1631803531; bh=wntXMQVPfNAlvsw/B4mAyFrI8LJDb845y3vVM0u8iFg=; h=From:To:Subject:Date:From; b=MircA7Fey+K8tQNrdz3EtKb91UFYLZjNHJnovfprFiX2tmEkmua6dgSddXhPPue6f vdGp83GClC8iKtg8+RiQ+9ddTnAYsnZOSw+Qtj2Q5+sWU1xTSfhWcgfelQCngijfVL KTvL5ay0J+pAwGN2qUGx3idLNJzyoAaTl6nA57HQ= X-Auth-ID: abbotti@mev.co.uk Received: by smtp17.relay.ord1d.emailsrvr.com (Authenticated sender: abbotti-AT-mev.co.uk) with ESMTPSA id 482D7201F5; Thu, 16 Sep 2021 10:45:30 -0400 (EDT) From: Ian Abbott To: linux-kernel@vger.kernel.org Cc: Ian Abbott , H Hartley Sweeten , Al Viro , Greg Kroah-Hartman , linux-staging@lists.linux.dev, stable@vger.kernel.org Subject: [PATCH] comedi: Fix memory leak in compat_insnlist() Date: Thu, 16 Sep 2021 15:44:38 +0100 Message-Id: <20210916144438.156858-1-abbotti@mev.co.uk> X-Mailer: git-send-email 2.33.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Classification-ID: 712c3295-ddca-4044-8232-b0e932842c75-1-1 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org `compat_insnlist()` handles the 32-bit version of the `COMEDI_INSNLIST` ioctl (whenwhen `CONFIG_COMPAT` is enabled). It allocates memory to temporarily hold an array of `struct comedi_insn` converted from the 32-bit version in user space. This memory is only being freed if there is a fault while filling the array, otherwise it is leaked. Add a call to `kfree()` to fix the leak. Fixes: b8d47d881305 ("comedi: get rid of compat_alloc_user_space() mess in COMEDI_INSNLIST compat" Cc: Al Viro Cc: Greg Kroah-Hartman Cc: linux-staging@lists.linux.dev Cc: # 5.13+ Signed-off-by: Ian Abbott --- N.B. Also need patches for 5.8+ from before comedi moved out of staging. --- drivers/comedi/comedi_fops.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/comedi/comedi_fops.c b/drivers/comedi/comedi_fops.c index df77b6bf5c64..763cea8418f8 100644 --- a/drivers/comedi/comedi_fops.c +++ b/drivers/comedi/comedi_fops.c @@ -3090,6 +3090,7 @@ static int compat_insnlist(struct file *file, unsigned long arg) mutex_lock(&dev->mutex); rc = do_insnlist_ioctl(dev, insns, insnlist32.n_insns, file); mutex_unlock(&dev->mutex); + kfree(insns); return rc; } -- 2.33.0