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,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=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 CC748C28E80 for ; Tue, 2 Mar 2021 06:39:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AA6FC6148E for ; Tue, 2 Mar 2021 06:39:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1573202AbhCBDT6 (ORCPT ); Mon, 1 Mar 2021 22:19:58 -0500 Received: from mail.kernel.org ([198.145.29.99]:48288 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243319AbhCAUXy (ORCPT ); Mon, 1 Mar 2021 15:23:54 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 8B26365408; Mon, 1 Mar 2021 18:05:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1614621932; bh=EbU4/cWEzERuVCCbwUVc4snFhY891p3qxhP6U46EhhE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=C2hrYTvVzRT8hByU79xPGcMOQACGlB/3DDlBqMHbTRGkDBAQu8GGUbvjpoNrAQj/L WWi+koRPS2++alFPsCusTZPOaAyB5DE0QGqmrI/WpseErSjhZuBUtuYMdKVQgrR15E 6iu+XGzhkUarN+yhIohGV+gWZ1IC4R3CQwu3YInY= 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 5.11 666/775] media: v4l: ioctl: Fix memory leak in video_usercopy Date: Mon, 1 Mar 2021 17:13:54 +0100 Message-Id: <20210301161234.294074990@linuxfoundation.org> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210301161201.679371205@linuxfoundation.org> References: <20210301161201.679371205@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: 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 | 32 ++++++++++++++------------------ 1 file changed, 14 insertions(+), 18 deletions(-) --- a/drivers/media/v4l2-core/v4l2-ioctl.c +++ b/drivers/media/v4l2-core/v4l2-ioctl.c @@ -3283,7 +3283,7 @@ 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; @@ -3318,27 +3318,21 @@ 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 = kvmalloc(array_size, GFP_KERNEL); + array_buf = kvmalloc(array_size, GFP_KERNEL); err = -ENOMEM; - if (NULL == mbuf) + if (array_buf == NULL) goto out_array_args; err = -EFAULT; if (in_compat_syscall()) - err = v4l2_compat_get_array_args(file, mbuf, user_ptr, - array_size, orig_cmd, - parg); + err = v4l2_compat_get_array_args(file, array_buf, + user_ptr, array_size, + orig_cmd, parg); else - err = copy_from_user(mbuf, user_ptr, array_size) ? + err = copy_from_user(array_buf, user_ptr, array_size) ? -EFAULT : 0; if (err) goto out_array_args; - *kernel_ptr = mbuf; + *kernel_ptr = array_buf; } /* Handles IOCTL */ @@ -3360,12 +3354,13 @@ video_usercopy(struct file *file, unsign if (in_compat_syscall()) { int put_err; - put_err = v4l2_compat_put_array_args(file, user_ptr, mbuf, - array_size, orig_cmd, - parg); + put_err = v4l2_compat_put_array_args(file, user_ptr, + array_buf, + array_size, + orig_cmd, parg); if (put_err) err = put_err; - } else if (copy_to_user(user_ptr, mbuf, array_size)) { + } else if (copy_to_user(user_ptr, array_buf, array_size)) { err = -EFAULT; } goto out_array_args; @@ -3381,6 +3376,7 @@ out_array_args: if (video_put_user((void __user *)arg, parg, cmd, orig_cmd)) err = -EFAULT; out: + kvfree(array_buf); kvfree(mbuf); return err; }