From 8f4502fa284478a5264afa8a5a95511276fa9b80 Mon Sep 17 00:00:00 2001 From: Colin Ian King Date: Thu, 30 Sep 2021 11:19:41 +0100 Subject: [PATCH] drm/virtio: fix potential integer overflow on shift of a int 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 Link: http://patchwork.freedesktop.org/patch/msgid/20210930101941.16546-1-colin.king@canonical.com Signed-off-by: Gerd Hoffmann --- 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 5618a1d..b3b0557 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; -- 2.7.4