From patchwork Fri Mar 5 12:22:59 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 394273 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,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, URIBL_BLOCKED, 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 2684AC43619 for ; Fri, 5 Mar 2021 12:44:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 131426502F for ; Fri, 5 Mar 2021 12:44:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233620AbhCEMob (ORCPT ); Fri, 5 Mar 2021 07:44:31 -0500 Received: from mail.kernel.org ([198.145.29.99]:32874 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233946AbhCEMoC (ORCPT ); Fri, 5 Mar 2021 07:44:02 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id BC30C64F4B; Fri, 5 Mar 2021 12:44:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1614948242; bh=F00Gzlwgd4PNrlafgw1hly9/O+G0X6GGjIT8+GDLR1w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FltfeAoF0Hwff9Ds1W9P/9mR3fU4fV3lMXxzDgj1UG8vNjSZbpcv5xtiB8cr1e5ni 7/Yff/aUl4sVi6vJSUIRFB4Lid0Odj31hAiFFx/qbasfo47vDotzRn2B+Nhdhi6kRY fduNAKHfHPrIkkR22ejIC3Emaxq+Ez8iqQACTRVc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Arnd Bergmann , syzbot+1115e79c8df6472c612b@syzkaller.appspotmail.com, Sakari Ailus , Arnd Bergmann , Hans Verkuil , Laurent Pinchart , Mauro Carvalho Chehab Subject: [PATCH 4.4 30/30] media: v4l: ioctl: Fix memory leak in video_usercopy Date: Fri, 5 Mar 2021 13:22:59 +0100 Message-Id: <20210305120850.909148856@linuxfoundation.org> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210305120849.381261651@linuxfoundation.org> References: <20210305120849.381261651@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Sakari Ailus commit fb18802a338b36f675a388fc03d2aa504a0d0899 upstream. When an IOCTL with argument size larger than 128 that also used array arguments were handled, two memory allocations were made but alas, only the latter one of them was released. This happened because there was only a single local variable to hold such a temporary allocation. Fix this by adding separate variables to hold the pointers to the temporary allocations. Reported-by: Arnd Bergmann Reported-by: syzbot+1115e79c8df6472c612b@syzkaller.appspotmail.com Fixes: d14e6d76ebf7 ("[media] v4l: Add multi-planar ioctl handling code") Cc: stable@vger.kernel.org Signed-off-by: Sakari Ailus Acked-by: Arnd Bergmann Acked-by: Hans Verkuil Reviewed-by: Laurent Pinchart Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Greg Kroah-Hartman --- drivers/media/v4l2-core/v4l2-ioctl.c | 19 +++++++------------ 1 file changed, 7 insertions(+), 12 deletions(-) --- a/drivers/media/v4l2-core/v4l2-ioctl.c +++ b/drivers/media/v4l2-core/v4l2-ioctl.c @@ -2710,7 +2710,7 @@ video_usercopy(struct file *file, unsign v4l2_kioctl func) { char sbuf[128]; - void *mbuf = NULL; + void *mbuf = NULL, *array_buf = NULL; void *parg = (void *)arg; long err = -EINVAL; bool has_array_args; @@ -2765,20 +2765,14 @@ video_usercopy(struct file *file, unsign has_array_args = err; if (has_array_args) { - /* - * When adding new types of array args, make sure that the - * parent argument to ioctl (which contains the pointer to the - * array) fits into sbuf (so that mbuf will still remain - * unused up to here). - */ - mbuf = kmalloc(array_size, GFP_KERNEL); + array_buf = kmalloc(array_size, GFP_KERNEL); err = -ENOMEM; - if (NULL == mbuf) + if (array_buf == NULL) goto out_array_args; err = -EFAULT; - if (copy_from_user(mbuf, user_ptr, array_size)) + if (copy_from_user(array_buf, user_ptr, array_size)) goto out_array_args; - *kernel_ptr = mbuf; + *kernel_ptr = array_buf; } /* Handles IOCTL */ @@ -2797,7 +2791,7 @@ video_usercopy(struct file *file, unsign if (has_array_args) { *kernel_ptr = (void __force *)user_ptr; - if (copy_to_user(user_ptr, mbuf, array_size)) + if (copy_to_user(user_ptr, array_buf, array_size)) err = -EFAULT; goto out_array_args; } @@ -2817,6 +2811,7 @@ out_array_args: } out: + kfree(array_buf); kfree(mbuf); return err; }