On 02/26, Eric Biggers wrote:
From: Eric Biggers ebiggers@google.com
If drm_gem_handle_create() fails in vkms_gem_create(), then the vkms_gem_object is freed twice: once when the reference is dropped by drm_gem_object_put_unlocked(), and again by the extra calls to drm_gem_object_release() and kfree().
Fix it by skipping the second release and free.
This bug was originally found in the vgem driver by syzkaller using fault injection, but I noticed it's also present in the vkms driver.
Fixes: 559e50fd34d1 ("drm/vkms: Add dumb operations") Cc: Rodrigo Siqueira rodrigosiqueiramelo@gmail.com Cc: Haneen Mohammed hamohammed.sa@gmail.com Cc: Daniel Vetter daniel.vetter@ffwll.ch Cc: Chris Wilson chris@chris-wilson.co.uk Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers ebiggers@google.com
drivers/gpu/drm/vkms/vkms_gem.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/vkms/vkms_gem.c b/drivers/gpu/drm/vkms/vkms_gem.c index 138b0bb325cf9..69048e73377dc 100644 --- a/drivers/gpu/drm/vkms/vkms_gem.c +++ b/drivers/gpu/drm/vkms/vkms_gem.c @@ -111,11 +111,8 @@ struct drm_gem_object *vkms_gem_create(struct drm_device *dev, ret = drm_gem_handle_create(file, &obj->gem, handle); drm_gem_object_put_unlocked(&obj->gem);
- if (ret) {
drm_gem_object_release(&obj->gem);kfree(obj);
- if (ret) return ERR_PTR(ret);
- }
return &obj->gem; } -- 2.21.0.rc2.261.ga7da99ff1b-goog
Hi,
Thanks for your patch! :)
The patch looks good for me. I also tested it under the IGT tests on my local VM and everything was fine.
Reviewed-by: Rodrigo Siqueira rodrigosiqueiramelo@gmail.com