linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* [PATCH] virtio: pci: Sanity check the bar index in find_shm_cap
@ 2022-03-21 15:49 Keir Fraser
  2022-03-22  3:36 ` Jason Wang
  0 siblings, 1 reply; 4+ messages in thread
From: Keir Fraser @ 2022-03-21 15:49 UTC (permalink / raw)
  To: Michael S. Tsirkin, Jason Wang; +Cc: Keir Fraser, virtualization, linux-kernel

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


^ permalink raw reply related	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2022-03-22 13:23 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-03-21 15:49 [PATCH] virtio: pci: Sanity check the bar index in find_shm_cap Keir Fraser
2022-03-22  3:36 ` Jason Wang
2022-03-22  9:20   ` Keir Fraser
2022-03-22 13:23     ` Michael S. Tsirkin

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).