The "offset" is a u32 that comes from the user. The bug is that the "offset + bytes" operation can have an integer overflow problem which leads to an out of bounds access.

Fixes: 4d60c5fd3f87 ("drm/i915/gvt: vGPU PCI configuration space virtualization") Signed-off-by: Dan Carpenter dan.carpenter@oracle.com --- drivers/gpu/drm/i915/gvt/cfg_space.c | 4 ++++ 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/i915/gvt/cfg_space.c b/drivers/gpu/drm/i915/gvt/cfg_space.c index b490e3db2e38..8a54dd3de91c 100644 --- a/drivers/gpu/drm/i915/gvt/cfg_space.c +++ b/drivers/gpu/drm/i915/gvt/cfg_space.c @@ -316,6 +316,10 @@ int intel_vgpu_emulate_cfg_write(struct intel_vgpu *vgpu, unsigned int offset, if (drm_WARN_ON(&i915->drm, bytes > 4)) return -EINVAL;

+ if (drm_WARN_ON(&i915->drm, + offset > vgpu->gvt->device_info.cfg_space_size)) + return -EINVAL; + if (drm_WARN_ON(&i915->drm, offset + bytes > vgpu->gvt->device_info.cfg_space_size)) return -EINVAL;