Messages in this thread Patch in this message | | | Date | Mon, 21 Mar 2022 15:49:31 +0000 | Subject | [PATCH] virtio: pci: Sanity check the bar index in find_shm_cap | From | Keir Fraser <> |
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The bar index is used as an index into the device's resource list and should be checked as within range for a standard bar.
Signed-off-by: Keir Fraser <keirf@google.com> --- drivers/virtio/virtio_pci_modern.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/drivers/virtio/virtio_pci_modern.c b/drivers/virtio/virtio_pci_modern.c index 5455bc041fb6..84bace98dff5 100644 --- a/drivers/virtio/virtio_pci_modern.c +++ b/drivers/virtio/virtio_pci_modern.c @@ -293,7 +293,7 @@ static int virtio_pci_find_shm_cap(struct pci_dev *dev, u8 required_id, for (pos = pci_find_capability(dev, PCI_CAP_ID_VNDR); pos > 0; pos = pci_find_next_capability(dev, pos, PCI_CAP_ID_VNDR)) { - u8 type, cap_len, id; + u8 type, cap_len, id, res_bar; u32 tmp32; u64 res_offset, res_length; @@ -317,7 +317,12 @@ static int virtio_pci_find_shm_cap(struct pci_dev *dev, u8 required_id, /* Type, and ID match, looks good */ pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap, - bar), bar); + bar), &res_bar); + if (res_bar >= PCI_STD_NUM_BARS) { + dev_err(&dev->dev, "%s: shm cap with bad bar: %d\n", + __func__, res_bar); + continue; + } /* Read the lower 32bit of length and offset */ pci_read_config_dword(dev, pos + offsetof(struct virtio_pci_cap, @@ -337,6 +342,7 @@ static int virtio_pci_find_shm_cap(struct pci_dev *dev, u8 required_id, length_hi), &tmp32); res_length |= ((u64)tmp32) << 32; + *bar = res_bar; *offset = res_offset; *len = res_length; -- 2.35.1.894.gb6a874cedc-goog
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