Re: [PATCH v2 0/5] Introduce new wrappers to copy user-arrays

[Zack Rusin <zackr@vmware.com>]

On Fri, 2023-09-08 at 21:59 +0200, Philipp Stanner wrote:
> 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(-)
> 

Series, and in particular the vmwgfx changes, look good to me.

Reviewed-by: Zack Rusin <zackr@vmware.com>