Hi! David Airlie suggested that we could implement new wrappers around (v)memdup_user() for duplicating user arrays. This small patch series first implements the two new wrapper functions memdup_array_user() and vmemdup_array_user(). They calculate the array-sizes safely, i.e., they return an error in case of an overflow. It then implements the new wrappers in two components in kernel/ and two in the drm-subsystem. In total, there are 18 files in the kernel that use (v)memdup_user() to duplicate arrays. My plan is to provide patches for the other 14 successively once this series has been merged. Changes since v1: - Insert new headers alphabetically ordered - Remove empty lines in functions' docstrings - Return -EOVERFLOW instead of -EINVAL from wrapper functions @Andy: I test-build it for UM on my x86_64. Builds successfully. A kernel build (localmodconfig) for my Fedora38 @ x86_64 does also boot fine. If there is more I can do to verify the early boot stages are fine, please let me know! P. Philipp Stanner (5): string.h: add array-wrappers for (v)memdup_user() kernel: kexec: copy user-array safely kernel: watch_queue: copy user-array safely drm_lease.c: copy user-array safely drm: vmgfx_surface.c: copy user-array safely drivers/gpu/drm/drm_lease.c | 4 +-- drivers/gpu/drm/vmwgfx/vmwgfx_surface.c | 4 +-- include/linux/string.h | 40 +++++++++++++++++++++++++ kernel/kexec.c | 2 +- kernel/watch_queue.c | 2 +- 5 files changed, 46 insertions(+), 6 deletions(-) -- 2.41.0
