From: Peilin Ye <yepeilin.cs@xxxxxxxxx>
commit 543e8669ed9bfb30545fd52bc0e047ca4df7fb31 upstream.
Compiler leaves a 4-byte hole near the end of `dev_info`, causing
amdgpu_info_ioctl() to copy uninitialized kernel stack memory to userspace
when `size` is greater than 356.
In 2015 we tried to fix this issue by doing `= {};` on `dev_info`, which
unfortunately does not initialize that 4-byte hole. Fix it by using
memset() instead.
Cc: stable@xxxxxxxxxxxxxxx
Fixes: c193fa91b918 ("drm/amdgpu: information leak in amdgpu_info_ioctl()")
Fixes: d38ceaf99ed0 ("drm/amdgpu: add core driver (v4)")
Suggested-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Reviewed-by: Christian König <christian.koenig@xxxxxxx>
Signed-off-by: Peilin Ye <yepeilin.cs@xxxxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
@@ -527,8 +527,9 @@ static int amdgpu_info_ioctl(struct drm_
return n ? -EFAULT : 0;
}
case AMDGPU_INFO_DEV_INFO: {
- struct drm_amdgpu_info_device dev_info = {};
+ struct drm_amdgpu_info_device dev_info;
+ memset(&dev_info, 0, sizeof(dev_info));
dev_info.device_id = dev->pdev->device;
dev_info.chip_rev = adev->rev_id;
dev_info.external_rev = adev->external_rev_id;
