linux-kernel - [PATCH 2/3] drm/amd: validate user pitch alignment

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: <20181221031053.240161-2-yuzhao@google.com>
Date:   Thu, 20 Dec 2018 20:10:52 -0700
From:   Yu Zhao <yuzhao@...gle.com>
To:     David Airlie <airlied@...ux.ie>, Daniel Vetter <daniel@...ll.ch>,
        Christian König <christian.koenig@....com>,
        Alex Deucher <alexander.deucher@....com>
Cc:     David Zhou <David1.Zhou@....com>, Samuel Li <Samuel.Li@....com>,
        Harry Wentland <harry.wentland@....com>,
        Junwei Zhang <Jerry.Zhang@....com>,
        Daniel Stone <daniels@...labora.com>,
        amd-gfx@...ts.freedesktop.org, dri-devel@...ts.freedesktop.org,
        linux-kernel@...r.kernel.org, Yu Zhao <yuzhao@...gle.com>
Subject: [PATCH 2/3] drm/amd: validate user pitch alignment

Userspace may request pitch alignment that is not supported by GPU.
Some requests 32, but GPU ignores it and uses default 64 when cpp is
4. If GEM object is allocated based on the smaller alignment, GPU
DMA will go out of bound.

For GPU that does frame buffer compression, DMA writing out of bound
memory will cause memory corruption.

Signed-off-by: Yu Zhao <yuzhao@...gle.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_display.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
index e309d26170db..755daa332f8a 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
@@ -527,6 +527,15 @@ amdgpu_display_user_framebuffer_create(struct drm_device *dev,
 	struct drm_gem_object *obj;
 	struct amdgpu_framebuffer *amdgpu_fb;
 	int ret;
+	struct amdgpu_device *adev = dev->dev_private;
+	int cpp = drm_format_plane_cpp(mode_cmd->pixel_format, 0);
+	int pitch = amdgpu_align_pitch(adev, mode_cmd->width, cpp, false);
+
+	if (mode_cmd->pitches[0] != pitch) {
+		dev_err(&dev->pdev->dev, "Invalid pitch: expecting %d but got %d\n",
+			pitch, mode_cmd->pitches[0]);
+		return ERR_PTR(-EINVAL);
+	}
 
 	obj = drm_gem_object_lookup(file_priv, mode_cmd->handles[0]);
 	if (obj ==  NULL) {
-- 
2.20.1.415.g653613c723-goog