[PATCH] drm/radeon: fix race condition UAF in radeon_gem_set_domain_ioctl

From: Min Li
Date: Sat May 27 2023 - 03:55:34 EST


Userspace can race to free the gobj(robj converted from), robj should not
be accessed again after drm_gem_object_put, otherwith it will result in
use-after-free.

Signed-off-by: Min Li <lm0963hack@xxxxxxxxx>
---
drivers/gpu/drm/radeon/radeon_gem.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/radeon/radeon_gem.c b/drivers/gpu/drm/radeon/radeon_gem.c
index bdc5af23f005..450c7cbdd28a 100644
--- a/drivers/gpu/drm/radeon/radeon_gem.c
+++ b/drivers/gpu/drm/radeon/radeon_gem.c
@@ -478,7 +478,7 @@ int radeon_gem_set_domain_ioctl(struct drm_device *dev, void *data,

drm_gem_object_put(gobj);
up_read(&rdev->exclusive_lock);
- r = radeon_gem_handle_lockup(robj->rdev, r);
+ r = radeon_gem_handle_lockup(rdev, r);
return r;
}

--
2.34.1