From: Vlad Tsyrklevich <[email protected]> commit 05692d7005a364add85c6e25a6c4447ce08f913a upstream.
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 <[email protected]> Signed-off-by: Alex Williamson <[email protected]> Signed-off-by: Willy Tarreau <[email protected]> --- drivers/vfio/pci/vfio_pci.c | 33 +++++++++++++++++++++------------ drivers/vfio/pci/vfio_pci_intrs.c | 2 +- 2 files changed, 22 insertions(+), 13 deletions(-) diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c index dc55bc2..a1d0fc4 100644 --- a/drivers/vfio/pci/vfio_pci.c +++ b/drivers/vfio/pci/vfio_pci.c @@ -344,8 +344,9 @@ 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); @@ -353,23 +354,31 @@ 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 4bc704e..bfe72a9 100644 --- a/drivers/vfio/pci/vfio_pci_intrs.c +++ b/drivers/vfio/pci/vfio_pci_intrs.c @@ -468,7 +468,7 @@ 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; -- 2.8.0.rc2.1.gbe9624a
