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authorVlad Tsyrklevich <vlad@tsyrklevich.net>2016-10-12 18:51:24 +0200
committerAlex Williamson <alex.williamson@redhat.com>2016-10-26 13:49:29 -0600
commit05692d7005a364add85c6e25a6c4447ce08f913a (patch)
treeffd118edd531db69da31501fd9684562b9a65227 /drivers/vfio
parent07d9a380680d1c0eb51ef87ff2eab5c994949e69 (diff)
vfio/pci: Fix integer overflows, bitmask check
The VFIO_DEVICE_SET_IRQS ioctl did not sufficiently sanitize user-supplied integers, potentially allowing memory corruption. This patch adds appropriate integer overflow checks, checks the range bounds for VFIO_IRQ_SET_DATA_NONE, and also verifies that only single element in the VFIO_IRQ_SET_DATA_TYPE_MASK bitmask is set. VFIO_IRQ_SET_ACTION_TYPE_MASK is already correctly checked later in vfio_pci_set_irqs_ioctl(). Furthermore, a kzalloc is changed to a kcalloc because the use of a kzalloc with an integer multiplication allowed an integer overflow condition to be reached without this patch. kcalloc checks for overflow and should prevent a similar occurrence. Signed-off-by: Vlad Tsyrklevich <vlad@tsyrklevich.net> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Diffstat (limited to 'drivers/vfio')
-rw-r--r--drivers/vfio/pci/vfio_pci.c33
-rw-r--r--drivers/vfio/pci/vfio_pci_intrs.c2
2 files changed, 22 insertions, 13 deletions
diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index d624a527777f..031bc08d000d 100644
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -829,8 +829,9 @@ static long vfio_pci_ioctl(void *device_data,
} else if (cmd == VFIO_DEVICE_SET_IRQS) {
struct vfio_irq_set hdr;
+ size_t size;
u8 *data = NULL;
- int ret = 0;
+ int max, ret = 0;
minsz = offsetofend(struct vfio_irq_set, count);
@@ -838,23 +839,31 @@ static long vfio_pci_ioctl(void *device_data,
return -EFAULT;
if (hdr.argsz < minsz || hdr.index >= VFIO_PCI_NUM_IRQS ||
+ hdr.count >= (U32_MAX - hdr.start) ||
hdr.flags & ~(VFIO_IRQ_SET_DATA_TYPE_MASK |
VFIO_IRQ_SET_ACTION_TYPE_MASK))
return -EINVAL;
- if (!(hdr.flags & VFIO_IRQ_SET_DATA_NONE)) {
- size_t size;
- int max = vfio_pci_get_irq_count(vdev, hdr.index);
+ max = vfio_pci_get_irq_count(vdev, hdr.index);
+ if (hdr.start >= max || hdr.start + hdr.count > max)
+ return -EINVAL;
- if (hdr.flags & VFIO_IRQ_SET_DATA_BOOL)
- size = sizeof(uint8_t);
- else if (hdr.flags & VFIO_IRQ_SET_DATA_EVENTFD)
- size = sizeof(int32_t);
- else
- return -EINVAL;
+ switch (hdr.flags & VFIO_IRQ_SET_DATA_TYPE_MASK) {
+ case VFIO_IRQ_SET_DATA_NONE:
+ size = 0;
+ break;
+ case VFIO_IRQ_SET_DATA_BOOL:
+ size = sizeof(uint8_t);
+ break;
+ case VFIO_IRQ_SET_DATA_EVENTFD:
+ size = sizeof(int32_t);
+ break;
+ default:
+ return -EINVAL;
+ }
- if (hdr.argsz - minsz < hdr.count * size ||
- hdr.start >= max || hdr.start + hdr.count > max)
+ if (size) {
+ if (hdr.argsz - minsz < hdr.count * size)
return -EINVAL;
data = memdup_user((void __user *)(arg + minsz),
diff --git a/drivers/vfio/pci/vfio_pci_intrs.c b/drivers/vfio/pci/vfio_pci_intrs.c
index c2e60893cd09..1c46045b0e7f 100644
--- a/drivers/vfio/pci/vfio_pci_intrs.c
+++ b/drivers/vfio/pci/vfio_pci_intrs.c
@@ -256,7 +256,7 @@ static int vfio_msi_enable(struct vfio_pci_device *vdev, int nvec, bool msix)
if (!is_irq_none(vdev))
return -EINVAL;
- vdev->ctx = kzalloc(nvec * sizeof(struct vfio_pci_irq_ctx), GFP_KERNEL);
+ vdev->ctx = kcalloc(nvec, sizeof(struct vfio_pci_irq_ctx), GFP_KERNEL);
if (!vdev->ctx)
return -ENOMEM;