Merge tag 'vfio-v4.9-rc4' of git://github.com/awilliam/linux-vfio

Pull VFIO fix from Alex Williamson:
 "SET_IRQS ioctl parameter sanitization (Vlad Tsyrklevich)"

* tag 'vfio-v4.9-rc4' of git://github.com/awilliam/linux-vfio:
  vfio/pci: Fix integer overflows, bitmask check

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;