linux-kernel - [PATCH 3.12 056/123] drm: Reject DRI1 hw lock ioctl functions for kms drivers

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <3c33fddf60b3b3c3a551f272944de6363e5478f8.1446021555.git.jslaby@suse.cz>
Date:	Wed, 28 Oct 2015 14:52:47 +0100
From:	Jiri Slaby <jslaby@...e.cz>
To:	stable@...r.kernel.org
Cc:	linux-kernel@...r.kernel.org,
	Daniel Vetter <daniel.vetter@...ll.ch>,
	Peter Antoine <peter.antoine@...el.com>,
	Daniel Vetter <daniel.vetter@...el.com>,
	Jiri Slaby <jslaby@...e.cz>
Subject: [PATCH 3.12 056/123] drm: Reject DRI1 hw lock ioctl functions for kms drivers

From: Daniel Vetter <daniel.vetter@...ll.ch>

3.12-stable review patch.  If anyone has any objections, please let me know.

===============

commit da168d81b44898404d281d5dbe70154ab5f117c1 upstream.

I've done some extensive history digging across libdrm, mesa and
xf86-video-{intel,nouveau,ati}. The only potential user of this with
kms drivers I could find was ttmtest, which once used drmGetLock
still. But that mistake was quickly fixed up. Even the intel xvmc
library (which otherwise was really good with using dri1 stuff in kms
mode) managed to never take the hw lock for dri2 (and hence kms).

Hence it should be save to unconditionally disallow this.

Cc: Peter Antoine <peter.antoine@...el.com>
Reviewed-by: Peter Antoine <peter.antoine@...el.com>
Signed-off-by: Daniel Vetter <daniel.vetter@...el.com>
Signed-off-by: Jiri Slaby <jslaby@...e.cz>
---
 drivers/gpu/drm/drm_lock.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/gpu/drm/drm_lock.c b/drivers/gpu/drm/drm_lock.c
index d752c96d6090..bdceb60998d3 100644
--- a/drivers/gpu/drm/drm_lock.c
+++ b/drivers/gpu/drm/drm_lock.c
@@ -58,6 +58,9 @@ int drm_lock(struct drm_device *dev, void *data, struct drm_file *file_priv)
 	struct drm_master *master = file_priv->master;
 	int ret = 0;
 
+	if (drm_core_check_feature(dev, DRIVER_MODESET))
+		return -EINVAL;
+
 	++file_priv->lock_count;
 
 	if (lock->context == DRM_KERNEL_CONTEXT) {
@@ -151,6 +154,9 @@ int drm_unlock(struct drm_device *dev, void *data, struct drm_file *file_priv)
 	struct drm_lock *lock = data;
 	struct drm_master *master = file_priv->master;
 
+	if (drm_core_check_feature(dev, DRIVER_MODESET))
+		return -EINVAL;
+
 	if (lock->context == DRM_KERNEL_CONTEXT) {
 		DRM_ERROR("Process %d using kernel context %d\n",
 			  task_pid_nr(current), lock->context);
-- 
2.6.2

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/