Jason Wang
2022-Mar-22 03:36 UTC
[PATCH] virtio: pci: Sanity check the bar index in find_shm_cap
On Mon, Mar 21, 2022 at 11:49 PM Keir Fraser <keirf at google.com> wrote:> > 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 at google.com>Patch looks good, do we need a similar check in vp_modern_map_capability()? Thanks> --- > 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 >