From: Alexey Kardashevskiy aik@ozlabs.ru
[ Upstream commit 338b4e10f939a71194d8ecef7ece205a942cec05 ]
The nvlink2 subdriver for IBM Witherspoon machines preregisters GPU memory in the IOMMI API so KVM TCE code can map this memory for DMA as well. This is done by mm_iommu_newdev() called from vfio_pci_nvgpu_regops::mmap.
In an unlikely event of failure the data->mem remains NULL and since mm_iommu_put() (which unregisters the region and unpins memory if that was regular memory) does not expect mem=NULL, it should not be called.
This adds a check to only call mm_iommu_put() for a valid data->mem.
Fixes: 7f92891778df ("vfio_pci: Add NVIDIA GV100GL [Tesla V100 SXM2] subdriver") Signed-off-by: Alexey Kardashevskiy aik@ozlabs.ru Signed-off-by: Alex Williamson alex.williamson@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/vfio/pci/vfio_pci_nvlink2.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/vfio/pci/vfio_pci_nvlink2.c b/drivers/vfio/pci/vfio_pci_nvlink2.c index f2983f0f84bea..3f5f8198a6bb1 100644 --- a/drivers/vfio/pci/vfio_pci_nvlink2.c +++ b/drivers/vfio/pci/vfio_pci_nvlink2.c @@ -97,8 +97,10 @@ static void vfio_pci_nvgpu_release(struct vfio_pci_device *vdev,
/* If there were any mappings at all... */ if (data->mm) { - ret = mm_iommu_put(data->mm, data->mem); - WARN_ON(ret); + if (data->mem) { + ret = mm_iommu_put(data->mm, data->mem); + WARN_ON(ret); + }
mmdrop(data->mm); }