From: Tom St Denis <tom.stdenis@amd.com>
Date: Mon, 2 May 2016 12:35:35 +0000 (-0400)
Subject: drm/amd/amdgpu: ring debugfs is read in increments of 4 bytes
X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=c71dbd93eb0039838de920ae1712ff65fd648290;p=deliverable%2Flinux.git

drm/amd/amdgpu: ring debugfs is read in increments of 4 bytes

If a user tries to read a non-multiple of 4 bytes it would have
read until the end of the ring potentially crashing the user
task.

Signed-off-by: Tom St Denis <tom.stdenis@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
index 5491696ac827..942111517e40 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
@@ -383,7 +383,7 @@ static ssize_t amdgpu_debugfs_ring_read(struct file *f, char __user *buf,
 	int r, i;
 	uint32_t value, result, early[3];
 
-	if (*pos & 3)
+	if (*pos & 3 || size & 3)
 		return -EINVAL;
 
 	result = 0;