From patchwork Fri Jun 13 09:00:20 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Zimmermann X-Patchwork-Id: 897014 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.223.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AF60A2741A0 for ; Fri, 13 Jun 2025 09:04:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=195.135.223.130 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749805480; cv=none; b=nyvvDTbKXvPsHYdEzrsNIDvTAPmA5Ls/vvH4FfeGIP6aEb2nao1DRClVwU7cSatXxuHSZpwx/+Rpm8m0MTirTKQkM+SssIagMVfKDisAZF91OAZZQMzpiUyb0/UbYPUB46iL8k9OCUjPsZpgNSGErQZqMPiWNqCnSkChVANtBYU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749805480; c=relaxed/simple; bh=y4jcw5C8Bbs1ENdzEDnlf9NsClVG+6XLxPOjcbgLpvY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=WC8rm3YJoHqCU3ZjBn78kJNavKq8jLEnByr2LxLB/7dzVv0WOWdZmM6HJiNKUzltx0V7Y0/7eWpG/42odYxeBVHdeKQ1mLR+LVZlmzk2qrdG8EcXf6f+zo4/pnL8nSyl6k54mayBs6BE8aqJ+dX+KLzbhRvz/oLgpVrE+oxHCv4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=suse.de; spf=pass smtp.mailfrom=suse.de; arc=none smtp.client-ip=195.135.223.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=suse.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.de Received: from imap1.dmz-prg2.suse.org (imap1.dmz-prg2.suse.org [IPv6:2a07:de40:b281:104:10:150:64:97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 0A00521268; Fri, 13 Jun 2025 09:04:37 +0000 (UTC) Authentication-Results: smtp-out1.suse.de; none Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id 785D713A9C; Fri, 13 Jun 2025 09:04:36 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id qH36G6TpS2inNAAAD6G6ig (envelope-from ); Fri, 13 Jun 2025 09:04:36 +0000 From: Thomas Zimmermann To: simona@ffwll.ch, airlied@gmail.com, mripard@kernel.org, maarten.lankhorst@linux.intel.com, geert@linux-m68k.org, tomi.valkeinen@ideasonboard.com Cc: dri-devel@lists.freedesktop.org, linux-mediatek@lists.infradead.org, freedreno@lists.freedesktop.org, linux-arm-msm@vger.kernel.org, imx@lists.linux.dev, linux-samsung-soc@vger.kernel.org, nouveau@lists.freedesktop.org, virtualization@lists.linux.dev, spice-devel@lists.freedesktop.org, linux-renesas-soc@vger.kernel.org, linux-rockchip@lists.infradead.org, linux-tegra@vger.kernel.org, intel-xe@lists.freedesktop.org, xen-devel@lists.xenproject.org, Thomas Zimmermann Subject: [PATCH v5 01/25] drm/dumb-buffers: Sanitize output on errors Date: Fri, 13 Jun 2025 11:00:20 +0200 Message-ID: <20250613090431.127087-2-tzimmermann@suse.de> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250613090431.127087-1-tzimmermann@suse.de> References: <20250613090431.127087-1-tzimmermann@suse.de> Precedence: bulk X-Mailing-List: linux-arm-msm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-Rspamd-Server: rspamd2.dmz-prg2.suse.org X-Spam-Level: X-Spamd-Result: default: False [-4.00 / 50.00]; REPLY(-4.00)[] X-Spam-Flag: NO X-Rspamd-Queue-Id: 0A00521268 X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-Rspamd-Action: no action X-Spam-Score: -4.00 The ioctls MODE_CREATE_DUMB and MODE_MAP_DUMB return results into a memory buffer supplied by user space. On errors, it is possible that intermediate values are being returned. The exact semantics depends on the DRM driver's implementation of these ioctls. Although this is most-likely not a security problem in practice, avoid any uncertainty by clearing the memory to 0 on errors. Signed-off-by: Thomas Zimmermann Reviewed-by: Tomi Valkeinen --- drivers/gpu/drm/drm_dumb_buffers.c | 40 ++++++++++++++++++++++-------- 1 file changed, 29 insertions(+), 11 deletions(-) diff --git a/drivers/gpu/drm/drm_dumb_buffers.c b/drivers/gpu/drm/drm_dumb_buffers.c index 70032bba1c97..9916aaf5b3f2 100644 --- a/drivers/gpu/drm/drm_dumb_buffers.c +++ b/drivers/gpu/drm/drm_dumb_buffers.c @@ -99,7 +99,30 @@ int drm_mode_create_dumb(struct drm_device *dev, int drm_mode_create_dumb_ioctl(struct drm_device *dev, void *data, struct drm_file *file_priv) { - return drm_mode_create_dumb(dev, data, file_priv); + struct drm_mode_create_dumb *args = data; + int err; + + err = drm_mode_create_dumb(dev, args, file_priv); + if (err) { + args->handle = 0; + args->pitch = 0; + args->size = 0; + } + return err; +} + +static int drm_mode_mmap_dumb(struct drm_device *dev, struct drm_mode_map_dumb *args, + struct drm_file *file_priv) +{ + if (!dev->driver->dumb_create) + return -ENOSYS; + + if (dev->driver->dumb_map_offset) + return dev->driver->dumb_map_offset(file_priv, dev, args->handle, + &args->offset); + else + return drm_gem_dumb_map_offset(file_priv, dev, args->handle, + &args->offset); } /** @@ -120,17 +143,12 @@ int drm_mode_mmap_dumb_ioctl(struct drm_device *dev, void *data, struct drm_file *file_priv) { struct drm_mode_map_dumb *args = data; + int err; - if (!dev->driver->dumb_create) - return -ENOSYS; - - if (dev->driver->dumb_map_offset) - return dev->driver->dumb_map_offset(file_priv, dev, - args->handle, - &args->offset); - else - return drm_gem_dumb_map_offset(file_priv, dev, args->handle, - &args->offset); + err = drm_mode_mmap_dumb(dev, args, file_priv); + if (err) + args->offset = 0; + return err; } int drm_mode_destroy_dumb(struct drm_device *dev, u32 handle,