Hello, Peter Robinson reported me a kernel bug in one of his aarch64 test boards and even though I was not able to reproduce it, I think that figured out what the problem was. It seems the cause is that a DRM driver doesn't set some of the struct drm fields copied to userspace via DRM_IOCTL_VERSION. Even though this is a driver bug, we can make drm_copy_field() more robust and warn about it instead of leading to an attempt to copy a NULL pointer. While looking at this, I also found that a variable in drm_copy_field() is not using the correct type. So I included that change in the patch-set too. Best regards, Javier Changes in v2: - Add Peter Robinson Tested-by and Thomas Zimmermann Reviewed-by tags. - Just warn if a value isn't set and report it as a string of length 0. (Thomas Zimmermann). Javier Martinez Canillas (2): drm: Use size_t type for len variable in drm_copy_field() drm: Prevent drm_copy_field() to attempt copying a NULL pointer drivers/gpu/drm/drm_ioctl.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) -- 2.36.1
