[PATCH 06/27] drm/radeon: fix a bug in the SA code

[j.glisse at gmail.com]

From: Christian König <deathsimple at vodafone.de>

Aligning offset can make it bigger than tmp->offset
leading to an overrun bug in the following subtraction.

v2: Against initial suspicions this can't happen in mainline,
    so no need to push it into stable.

Signed-off-by: Christian König <deathsimple at vodafone.de>
Reviewed-by: Michel Dänzer <michel.daenzer at amd.com>
Reviewed-by: Jerome Glisse <jglisse at redhat.com>
---
 drivers/gpu/drm/radeon/radeon_sa.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/gpu/drm/radeon/radeon_sa.c b/drivers/gpu/drm/radeon/radeon_sa.c
index 4cce47e..8fbfe69 100644
--- a/drivers/gpu/drm/radeon/radeon_sa.c
+++ b/drivers/gpu/drm/radeon/radeon_sa.c
@@ -150,7 +150,7 @@ int radeon_sa_bo_new(struct radeon_device *rdev,
 	offset = 0;
 	list_for_each_entry(tmp, &sa_manager->sa_bo, list) {
 		/* room before this object ? */
-		if ((tmp->offset - offset) >= size) {
+		if (offset < tmp->offset && (tmp->offset - offset) >= size) {
 			head = tmp->list.prev;
 			goto out;
 		}
-- 
1.7.7.6