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[next] drm/virtio: fix another potential integer overflow on shift of a int

Message ID 20210930102748.16922-1-colin.king@canonical.com (mailing list archive)
State New, archived
Headers show
Series [next] drm/virtio: fix another potential integer overflow on shift of a int | expand

Commit Message

Colin King Sept. 30, 2021, 10:27 a.m. UTC 
From: Colin Ian King <colin.king@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 value is 32 or more this can lead to an overflow
(value can be in range 0..MAX_CAPSET_ID (63). Fix this by shifting
the value 1ULL instead.

Addresses-Coverity: ("Uninitentional integer overflow")
Fixes: 4fb530e5caf7 ("drm/virtio: implement context init: support init ioctl")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 drivers/gpu/drm/virtio/virtgpu_ioctl.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
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Patch

diff --git a/drivers/gpu/drm/virtio/virtgpu_ioctl.c b/drivers/gpu/drm/virtio/virtgpu_ioctl.c
index b3b0557d72cf..0007e423d885 100644
--- a/drivers/gpu/drm/virtio/virtgpu_ioctl.c
+++ b/drivers/gpu/drm/virtio/virtgpu_ioctl.c
@@ -774,7 +774,7 @@  static int virtio_gpu_context_init_ioctl(struct drm_device *dev,
 				goto out_unlock;
 			}
 
-			if ((vgdev->capset_id_mask & (1 << value)) == 0) {
+			if ((vgdev->capset_id_mask & (1ULL << value)) == 0) {
 				ret = -EINVAL;
 				goto out_unlock;
 			}