From 702809dabdecca807bdd50cfdcc1c980feb2ba62 Mon Sep 17 00:00:00 2001 From: Matt Evans Date: Mon, 11 May 2026 07:58:24 -0700 Subject: [PATCH] vfio/pci: Check BAR resources before exporting a DMABUF A DMABUF exports access to BAR resources and, although they are requested at startup time, we need to ensure they really were reserved before exporting. Otherwise, it's possible to access unreserved resources through the export. Add a check to the DMABUF-creation path. Fixes: 5d74781ebc86c ("vfio/pci: Add dma-buf export support for MMIO regions") Signed-off-by: Matt Evans Link: https://lore.kernel.org/r/20260511145829.2993601-3-mattev@meta.com Signed-off-by: Alex Williamson --- drivers/vfio/pci/vfio_pci_dmabuf.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/vfio/pci/vfio_pci_dmabuf.c b/drivers/vfio/pci/vfio_pci_dmabuf.c index fdc22e8b4656..1a177ce7de54 100644 --- a/drivers/vfio/pci/vfio_pci_dmabuf.c +++ b/drivers/vfio/pci/vfio_pci_dmabuf.c @@ -244,9 +244,11 @@ int vfio_pci_core_feature_dma_buf(struct vfio_pci_core_device *vdev, u32 flags, return -EINVAL; /* - * For PCI the region_index is the BAR number like everything else. + * For PCI the region_index is the BAR number like everything + * else. Check that PCI resources have been claimed for it. */ - if (get_dma_buf.region_index >= VFIO_PCI_ROM_REGION_INDEX) + if (get_dma_buf.region_index >= VFIO_PCI_ROM_REGION_INDEX || + vfio_pci_core_setup_barmap(vdev, get_dma_buf.region_index)) return -ENODEV; dma_ranges = memdup_array_user(&arg->dma_ranges, get_dma_buf.nr_ranges,