4.19-stable review patch. If anyone has any objections, please let me know.
------------------ From: Eric Biggers <[email protected]> commit 36b6c9ed45afe89045973e8dee1b004dd5372d40 upstream. 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 <[email protected]> Cc: Haneen Mohammed <[email protected]> Cc: Daniel Vetter <[email protected]> Cc: Chris Wilson <[email protected]> Cc: [email protected] Signed-off-by: Eric Biggers <[email protected]> Reviewed-by: Chris Wilson <[email protected]> Reviewed-by: Rodrigo Siqueira <[email protected]> Signed-off-by: Rodrigo Siqueira <[email protected]> Link: https://patchwork.freedesktop.org/patch/msgid/[email protected] Signed-off-by: Maxime Ripard <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/gpu/drm/vkms/vkms_gem.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) --- a/drivers/gpu/drm/vkms/vkms_gem.c +++ b/drivers/gpu/drm/vkms/vkms_gem.c @@ -110,11 +110,8 @@ struct drm_gem_object *vkms_gem_create(s 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; }
