This patch checks for overflows in QUEUE_NOTIFY and QUEUE_SEL in
the PCI and MMIO operation handling paths. Further, the return
value type of get_vq_count is changed from int to u32 since negative
doesn't carry any semantic meaning.
Signed-off-by: Martin Radev <martin.b.radev@xxxxxxxxx>
---
include/kvm/virtio.h | 2 +-
virtio/9p.c | 2 +-
virtio/balloon.c | 2 +-
virtio/blk.c | 2 +-
virtio/console.c | 2 +-
virtio/mmio.c | 25 ++++++++++++++++++++++---
virtio/net.c | 2 +-
virtio/pci.c | 21 ++++++++++++++++++---
virtio/rng.c | 2 +-
virtio/scsi.c | 2 +-
virtio/vsock.c | 2 +-
11 files changed, 49 insertions(+), 15 deletions(-)
diff --git a/include/kvm/virtio.h b/include/kvm/virtio.h
index 3880e74..40f2a6d 100644
--- a/include/kvm/virtio.h
+++ b/include/kvm/virtio.h
@@ -187,7 +187,7 @@ struct virtio_ops {
size_t (*get_config_size)(struct kvm *kvm, void *dev);
u32 (*get_host_features)(struct kvm *kvm, void *dev);
void (*set_guest_features)(struct kvm *kvm, void *dev, u32 features);
- int (*get_vq_count)(struct kvm *kvm, void *dev);
+ u32 (*get_vq_count)(struct kvm *kvm, void *dev);
int (*init_vq)(struct kvm *kvm, void *dev, u32 vq, u32 page_size,
u32 align, u32 pfn);
void (*exit_vq)(struct kvm *kvm, void *dev, u32 vq);
diff --git a/virtio/9p.c b/virtio/9p.c
index 89bec5e..8f1fc1f 100644
--- a/virtio/9p.c
+++ b/virtio/9p.c
@@ -1468,7 +1468,7 @@ static int set_size_vq(struct kvm *kvm, void *dev, u32 vq, int size)
return size;
}
-static int get_vq_count(struct kvm *kvm, void *dev)
+static u32 get_vq_count(struct kvm *kvm, void *dev)
{
return NUM_VIRT_QUEUES;
}
diff --git a/virtio/balloon.c b/virtio/balloon.c
index 233a3a5..de3882e 100644
--- a/virtio/balloon.c
+++ b/virtio/balloon.c
@@ -249,7 +249,7 @@ static int set_size_vq(struct kvm *kvm, void *dev, u32 vq, int size)
return size;
}
-static int get_vq_count(struct kvm *kvm, void *dev)
+static u32 get_vq_count(struct kvm *kvm, void *dev)
{
return NUM_VIRT_QUEUES;
}
diff --git a/virtio/blk.c b/virtio/blk.c
index 9164b51..46918a4 100644
--- a/virtio/blk.c
+++ b/virtio/blk.c
@@ -289,7 +289,7 @@ static int set_size_vq(struct kvm *kvm, void *dev, u32 vq, int size)
return size;
}
-static int get_vq_count(struct kvm *kvm, void *dev)
+static u32 get_vq_count(struct kvm *kvm, void *dev)
{
return NUM_VIRT_QUEUES;
}
diff --git a/virtio/console.c b/virtio/console.c
index 00bafa2..84466d0 100644
--- a/virtio/console.c
+++ b/virtio/console.c
@@ -214,7 +214,7 @@ static int set_size_vq(struct kvm *kvm, void *dev, u32 vq, int size)
return size;
}
-static int get_vq_count(struct kvm *kvm, void *dev)
+static u32 get_vq_count(struct kvm *kvm, void *dev)
{
return VIRTIO_CONSOLE_NUM_QUEUES;
}
diff --git a/virtio/mmio.c b/virtio/mmio.c
index 32bba17..fd9a411 100644
--- a/virtio/mmio.c
+++ b/virtio/mmio.c
@@ -171,14 +171,26 @@ static void virtio_mmio_config_out(struct kvm_cpu *vcpu,
struct virtio_mmio *vmmio = vdev->virtio;
struct kvm *kvm = vmmio->kvm;
u32 val = 0;
+ u32 vq_count = 0;
+ vq_count = vdev->ops->get_vq_count(kvm, vmmio->dev);
switch (addr) {
case VIRTIO_MMIO_HOST_FEATURES_SEL:
case VIRTIO_MMIO_GUEST_FEATURES_SEL:
- case VIRTIO_MMIO_QUEUE_SEL:
val = ioport__read32(data);
*(u32 *)(((void *)&vmmio->hdr) + addr) = val;
break;
+ case VIRTIO_MMIO_QUEUE_SEL:
+ {
+ val = ioport__read32(data);
+ if (val >= vq_count) {
+ pr_warning("QUEUE_SEL value (%u) is larger than VQ count (%u)\n",
+ val, vq_count);
+ break;
+ }
+ *(u32 *)(((void *)&vmmio->hdr) + addr) = val;
+ break;
+ }
case VIRTIO_MMIO_STATUS:
vmmio->hdr.status = ioport__read32(data);
if (!vmmio->hdr.status) /* Sample endianness on reset */
@@ -222,6 +234,11 @@ static void virtio_mmio_config_out(struct kvm_cpu *vcpu,
break;
case VIRTIO_MMIO_QUEUE_NOTIFY:
val = ioport__read32(data);
+ if (val > vq_count) {
+ pr_warning("QUEUE_NOTIFY value (%u) is larger than VQ count (%u)\n",
+ val, vq_count);
+ break;
+ }
vdev->ops->notify_vq(vmmio->kvm, vmmio->dev, val);
break;
case VIRTIO_MMIO_INTERRUPT_ACK:
@@ -341,10 +358,12 @@ int virtio_mmio_init(struct kvm *kvm, void *dev, struct virtio_device *vdev,
int virtio_mmio_reset(struct kvm *kvm, struct virtio_device *vdev)
{
- int vq;
+ u32 vq;
struct virtio_mmio *vmmio = vdev->virtio;
+ u32 vq_count;
- for (vq = 0; vq < vdev->ops->get_vq_count(kvm, vmmio->dev); vq++)
+ vq_count = vdev->ops->get_vq_count(kvm, vmmio->dev);
+ for (vq = 0; vq < vq_count; vq++)
virtio_mmio_exit_vq(kvm, vdev, vq);
return 0;
diff --git a/virtio/net.c b/virtio/net.c
index 75d9ae5..9a25bfa 100644
--- a/virtio/net.c
+++ b/virtio/net.c
@@ -753,7 +753,7 @@ static int set_size_vq(struct kvm *kvm, void *dev, u32 vq, int size)
return size;
}
-static int get_vq_count(struct kvm *kvm, void *dev)
+static u32 get_vq_count(struct kvm *kvm, void *dev)
{
struct net_dev *ndev = dev;
diff --git a/virtio/pci.c b/virtio/pci.c
index 50fdaa4..60ae2cb 100644
--- a/virtio/pci.c
+++ b/virtio/pci.c
@@ -308,9 +308,11 @@ static bool virtio_pci__data_out(struct kvm_cpu *vcpu, struct virtio_device *vde
struct virtio_pci *vpci;
struct kvm *kvm;
u32 val;
+ u32 vq_count;
kvm = vcpu->kvm;
vpci = vdev->virtio;
+ vq_count = vdev->ops->get_vq_count(kvm, vpci->dev);
switch (offset) {
case VIRTIO_PCI_GUEST_FEATURES:
@@ -330,10 +332,21 @@ static bool virtio_pci__data_out(struct kvm_cpu *vcpu, struct virtio_device *vde
}
break;
case VIRTIO_PCI_QUEUE_SEL:
- vpci->queue_selector = ioport__read16(data);
+ val = ioport__read16(data);
+ if (val >= vq_count) {
+ pr_warning("QUEUE_SEL value (%u) is larger than VQ count (%u)\n",
+ val, vq_count);
+ return false;
+ }
+ vpci->queue_selector = val;
break;
case VIRTIO_PCI_QUEUE_NOTIFY:
val = ioport__read16(data);
+ if (val >= vq_count) {
+ pr_warning("QUEUE_SEL value (%u) is larger than VQ count (%u)\n",
+ val, vq_count);
+ return false;
+ }
vdev->ops->notify_vq(kvm, vpci->dev, val);
break;
case VIRTIO_PCI_STATUS:
@@ -626,10 +639,12 @@ int virtio_pci__init(struct kvm *kvm, void *dev, struct virtio_device *vdev,
int virtio_pci__reset(struct kvm *kvm, struct virtio_device *vdev)
{
- int vq;
+ u32 vq;
struct virtio_pci *vpci = vdev->virtio;
+ u32 vq_count;
- for (vq = 0; vq < vdev->ops->get_vq_count(kvm, vpci->dev); vq++)
+ vq_count = vdev->ops->get_vq_count(kvm, vpci->dev);
+ for (vq = 0; vq < vq_count; vq++)
virtio_pci_exit_vq(kvm, vdev, vq);
return 0;
diff --git a/virtio/rng.c b/virtio/rng.c
index c7835a0..d9b9e68 100644
--- a/virtio/rng.c
+++ b/virtio/rng.c
@@ -147,7 +147,7 @@ static int set_size_vq(struct kvm *kvm, void *dev, u32 vq, int size)
return size;
}
-static int get_vq_count(struct kvm *kvm, void *dev)
+static u32 get_vq_count(struct kvm *kvm, void *dev)
{
return NUM_VIRT_QUEUES;
}
diff --git a/virtio/scsi.c b/virtio/scsi.c
index 37418f8..cdf553d 100644
--- a/virtio/scsi.c
+++ b/virtio/scsi.c
@@ -174,7 +174,7 @@ static int set_size_vq(struct kvm *kvm, void *dev, u32 vq, int size)
return size;
}
-static int get_vq_count(struct kvm *kvm, void *dev)
+static u32 get_vq_count(struct kvm *kvm, void *dev)
{
return NUM_VIRT_QUEUES;
}
diff --git a/virtio/vsock.c b/virtio/vsock.c
index 2df04d7..7d523df 100644
--- a/virtio/vsock.c
+++ b/virtio/vsock.c
@@ -202,7 +202,7 @@ static void notify_vq_gsi(struct kvm *kvm, void *dev, u32 vq, u32 gsi)
die_perror("VHOST_SET_VRING_CALL failed");
}
-static int get_vq_count(struct kvm *kvm, void *dev)
+static u32 get_vq_count(struct kvm *kvm, void *dev)
{
return VSOCK_VQ_MAX;
}
--
2.25.1
