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| author | Vlad Tsyrklevich <vlad@tsyrklevich.net> | 2016-10-12 18:51:24 +0200 |
|---|---|---|
| committer | Alex Williamson <alex.williamson@redhat.com> | 2016-10-26 13:49:29 -0600 |
| commit | 05692d7005a364add85c6e25a6c4447ce08f913a (patch) | |
| tree | ffd118edd531db69da31501fd9684562b9a65227 /drivers/vfio | |
| parent | 07d9a380680d1c0eb51ef87ff2eab5c994949e69 (diff) | |
| download | linux-05692d7005a364add85c6e25a6c4447ce08f913a.tar.gz linux-05692d7005a364add85c6e25a6c4447ce08f913a.tar.bz2 linux-05692d7005a364add85c6e25a6c4447ce08f913a.zip | |
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.c | 33 | ||||
| -rw-r--r-- | 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 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; |