From patchwork Wed Nov 7 15:18:11 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Colin Ian King X-Patchwork-Id: 994331 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=lists.ubuntu.com (client-ip=91.189.94.19; helo=huckleberry.canonical.com; envelope-from=kernel-team-bounces@lists.ubuntu.com; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=canonical.com Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 42qqmr3Sccz9sDB; Thu, 8 Nov 2018 02:18:20 +1100 (AEDT) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.86_2) (envelope-from ) id 1gKPav-0008VM-Qz; Wed, 07 Nov 2018 15:18:13 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtps (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:128) (Exim 4.86_2) (envelope-from ) id 1gKPau-0008UN-OI for kernel-team@lists.ubuntu.com; Wed, 07 Nov 2018 15:18:12 +0000 Received: from 1.general.cking.uk.vpn ([10.172.193.212] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.76) (envelope-from ) id 1gKPau-0006bc-F3; Wed, 07 Nov 2018 15:18:12 +0000 From: Colin King To: kernel-team@lists.ubuntu.com Subject: [PATCH] drm: fix NULL pointer access by wrong ioctl Date: Wed, 7 Nov 2018 15:18:11 +0000 Message-Id: <20181107151811.28423-2-colin.king@canonical.com> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181107151811.28423-1-colin.king@canonical.com> References: <20181107151811.28423-1-colin.king@canonical.com> MIME-Version: 1.0 X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.20 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: "kernel-team" From: Colin Ian King BugLink: https://bugs.launchpad.net/bugs/1797546 If user uses wrong ioctl command with _IOC_NONE and argument size greater than 0, it can cause NULL pointer access from memset of line 463. If _IOC_NONE, don't memset to 0 for kdata. Signed-off-by: Zhaowei Yuan Reviewed-by: David Herrmann Cc: Signed-off-by: Dave Airlie (backported from commit 1539fb9bd405ee32282ea0a38404f9e008ac5b7a) Signed-off-by: Colin Ian King Acked-by: Stefan Bader Acked-by: Kleber Sacilotto de Souza --- drivers/gpu/drm/drm_drv.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c index d9137e4..ef65779 100644 --- a/drivers/gpu/drm/drm_drv.c +++ b/drivers/gpu/drm/drm_drv.c @@ -383,8 +383,9 @@ long drm_ioctl(struct file *filp, retcode = -EFAULT; goto err_i1; } - } else + } else if (cmd & IOC_OUT) { memset(kdata, 0, usize); + } if (ioctl->flags & DRM_UNLOCKED) retcode = func(dev, kdata, file_priv);