Colin King
2021-Sep-30 10:19 UTC
[PATCH][next] drm/virtio: fix potential integer overflow on shift of a int
From: Colin Ian King <colin.king at canonical.com>
The left shift of unsigned int 32 bit integer constant 1 is evaluated
using 32 bit arithmetic and then assigned to a signed 64 bit integer.
In the case where i is 32 or more this can lead to an overflow. Fix
this by shifting the value 1ULL instead.
Addresses-Coverity: ("Uninitentional integer overflow")
Fixes: 8d6b006e1f51 ("drm/virtio: implement context init: handle
VIRTGPU_CONTEXT_PARAM_POLL_RINGS_MASK")
Signed-off-by: Colin Ian King <colin.king at canonical.com>
---
drivers/gpu/drm/virtio/virtgpu_ioctl.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/virtio/virtgpu_ioctl.c
b/drivers/gpu/drm/virtio/virtgpu_ioctl.c
index 5618a1d5879c..b3b0557d72cf 100644
--- a/drivers/gpu/drm/virtio/virtgpu_ioctl.c
+++ b/drivers/gpu/drm/virtio/virtgpu_ioctl.c
@@ -819,7 +819,7 @@ static int virtio_gpu_context_init_ioctl(struct drm_device
*dev,
if (vfpriv->ring_idx_mask) {
valid_ring_mask = 0;
for (i = 0; i < vfpriv->num_rings; i++)
- valid_ring_mask |= 1 << i;
+ valid_ring_mask |= 1ULL << i;
if (~valid_ring_mask & vfpriv->ring_idx_mask) {
ret = -EINVAL;
--
2.32.0