[PATCH v2 1/3] iommufd/viommu: Release the igroup lock on the vdevice_size error path

[Nicolin Chen]

iommufd_vdevice_alloc_ioctl() takes idev->igroup->lock, then validates the
driver's vdevice_size against the core structure size with a WARN_ON_ONCE.
On failure that guard jumps to out_put_idev, below out_unlock_igroup, so it
skips the mutex_unlock(), leaving the igroup lock held and deadlocking the
next vDEVICE operation on that group.

Jump to out_unlock_igroup instead.

Fixes: ed42eee797ff3 ("iommufd/viommu: Add driver-defined vDEVICE support")
Cc: stable at vger.kernel.org
Reviewed-by: Kevin Tian <kevin.tian at intel.com>
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Nicolin Chen <nicolinc at nvidia.com>
---
 drivers/iommu/iommufd/viommu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iommu/iommufd/viommu.c b/drivers/iommu/iommufd/viommu.c
index 4081deda9b33d..0c12c7e352a14 100644
--- a/drivers/iommu/iommufd/viommu.c
+++ b/drivers/iommu/iommufd/viommu.c
@@ -189,7 +189,7 @@ int iommufd_vdevice_alloc_ioctl(struct iommufd_ucmd *ucmd)
 		if (WARN_ON_ONCE(viommu->ops->vdevice_size < vdev_size ||
 				 !viommu->ops->vdevice_init)) {
 			rc = -EOPNOTSUPP;
-			goto out_put_idev;
+			goto out_unlock_igroup;
 		}
 		vdev_size = viommu->ops->vdevice_size;
 	}
-- 
2.43.0