[PATCH 6/9] drm/i915/gvt: Add missing module_put() in error unwind

From: Jason Gunthorpe <jgg@nvidia.com>
To: Alexander Gordeev <agordeev@linux.ibm.com>,
	David Airlie <airlied@linux.ie>,
	Tony Krowiak <akrowiak@linux.ibm.com>,
	Alex Williamson <alex.williamson@redhat.com>,
	Christian Borntraeger <borntraeger@linux.ibm.com>,
	Cornelia Huck <cohuck@redhat.com>,
	Jonathan Corbet <corbet@lwn.net>, Daniel Vetter <daniel@ffwll.ch>,
	dri-devel@lists.freedesktop.org,
	Eric Farman <farman@linux.ibm.com>,
	Harald Freudenberger <freude@linux.ibm.com>,
	Vasily Gorbik <gor@linux.ibm.com>,
	Heiko Carstens <hca@linux.ibm.com>,
	intel-gfx@lists.freedesktop.org,
	intel-gvt-dev@lists.freedesktop.org,
	Jani Nikula <jani.nikula@linux.intel.com>,
	Jason Herne <jjherne@linux.ibm.com>,
	Joonas Lahtinen <joonas.lahtinen@linux.intel.com>,
	kvm@vger.kernel.org, Kirti Wankhede <kwankhede@nvidia.com>,
	linux-doc@vger.kernel.org, linux-s390@vger.kernel.org,
	Matthew Rosato <mjrosato@linux.ibm.com>,
	Peter Oberparleiter <oberpar@linux.ibm.com>,
	Halil Pasic <pasic@linux.ibm.com>,
	Rodrigo Vivi <rodrigo.vivi@intel.com>,
	Sven Schnelle <svens@linux.ibm.com>,
	Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>,
	Vineeth Vijayan <vneethv@linux.ibm.com>,
	Zhenyu Wang <zhenyuw@linux.intel.com>,
	Zhi Wang <zhi.a.wang@intel.com>
Cc: "Tian, Kevin" <kevin.tian@intel.com>,
	"Liu, Yi L" <yi.l.liu@intel.com>, Christoph Hellwig <hch@lst.de>
Subject: [PATCH 6/9] drm/i915/gvt: Add missing module_put() in error unwind
Date: Tue, 12 Apr 2022 12:53:33 -0300	[thread overview]
Message-ID: <6-v1-a8faf768d202+125dd-vfio_mdev_no_group_jgg@nvidia.com> (raw)
In-Reply-To: <0-v1-a8faf768d202+125dd-vfio_mdev_no_group_jgg@nvidia.com>

try_module_get() must be undone if kvmgt_guest_init() fails or we leak the
module reference count on the failure path since the close_device op is
never called in this case.

Fixes: 9bdb073464d6 ("drm/i915/gvt: Change KVMGT as self load module")
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
---
 drivers/gpu/drm/i915/gvt/kvmgt.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c
index 3302d5d4d92146..d7c22a2601f3ad 100644
--- a/drivers/gpu/drm/i915/gvt/kvmgt.c
+++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
@@ -952,13 +952,16 @@ static int intel_vgpu_open_device(struct mdev_device *mdev)
 
 	ret = kvmgt_guest_init(mdev);
 	if (ret)
-		goto undo_group;
+		goto undo_module_get;
 
 	intel_gvt_ops->vgpu_activate(vgpu);
 
 	atomic_set(&vdev->released, 0);
 	return ret;
 
+undo_module_get:
+	module_put(THIS_MODULE);
+
 undo_group:
 	vfio_group_put_external_user(vdev->vfio_group);
 	vdev->vfio_group = NULL;
-- 
2.35.1

