From: Peilin Ye yepeilin.cs@gmail.com
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@vger.kernel.org Fixes: c193fa91b918 ("drm/amdgpu: information leak in amdgpu_info_ioctl()") Fixes: d38ceaf99ed0 ("drm/amdgpu: add core driver (v4)") Suggested-by: Dan Carpenter dan.carpenter@oracle.com Reviewed-by: Christian König christian.koenig@amd.com Signed-off-by: Peilin Ye yepeilin.cs@gmail.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- 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;