From: Keir Fraser <keirf@google.com>
To: "Michael S. Tsirkin" <mst@redhat.com>, Jason Wang <jasowang@redhat.com>
Cc: kernel-team@android.com, Keir Fraser <keirf@google.com>,
virtualization@lists.linux-foundation.org,
linux-kernel@vger.kernel.org
Subject: [PATCH v2] virtio: pci: sanity check bar indexes
Date: Tue, 22 Mar 2022 15:19:52 +0000 [thread overview]
Message-ID: <20220322151952.2950143-1-keirf@google.com> (raw)
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.
Also clean up an existing check to consistently use PCI_STD_NUM_BARS.
Signed-off-by: Keir Fraser <keirf@google.com>
---
drivers/virtio/virtio_pci_modern.c | 10 ++++++++--
drivers/virtio/virtio_pci_modern_dev.c | 8 +++++++-
2 files changed, 15 insertions(+), 3 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;
diff --git a/drivers/virtio/virtio_pci_modern_dev.c b/drivers/virtio/virtio_pci_modern_dev.c
index e8b3ff2b9fbc..a6911d1e212a 100644
--- a/drivers/virtio/virtio_pci_modern_dev.c
+++ b/drivers/virtio/virtio_pci_modern_dev.c
@@ -35,6 +35,12 @@ vp_modern_map_capability(struct virtio_pci_modern_device *mdev, int off,
pci_read_config_dword(dev, off + offsetof(struct virtio_pci_cap, length),
&length);
+ if (bar >= PCI_STD_NUM_BARS) {
+ dev_err(&dev->dev,
+ "virtio_pci: bad capability bar %u\n", bar);
+ return NULL;
+ }
+
if (length <= start) {
dev_err(&dev->dev,
"virtio_pci: bad capability len %u (>%u expected)\n",
@@ -120,7 +126,7 @@ static inline int virtio_pci_find_capability(struct pci_dev *dev, u8 cfg_type,
&bar);
/* Ignore structures with reserved BAR values */
- if (bar > 0x5)
+ if (bar >= PCI_STD_NUM_BARS)
continue;
if (type == cfg_type) {
--
2.35.1.894.gb6a874cedc-goog
next reply other threads:[~2022-03-22 15:20 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-22 15:19 Keir Fraser [this message]
2022-03-23 7:57 ` [PATCH v2] virtio: pci: sanity check bar indexes Jason Wang
2022-03-23 9:13 ` Keir Fraser
2022-03-23 9:21 ` Jason Wang
2022-03-23 12:01 ` Michael S. Tsirkin
2022-03-23 13:21 ` Keir Fraser
2022-03-23 13:23 ` Michael S. Tsirkin
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