Re: [PATCH] cxl/mem: Force array size of mem_commands[] to CXL_MEM_COMMAND_ID_MAX

[Dan Williams]

On Wed, Mar 24, 2021 at 7:17 AM Robert Richter <rrichter@xxxxxxx> wrote:
>
> Typically the mem_commands[] array is in sync with 'enum { CXL_CMDS }'.
> Current code works well.
>
> However, the array size of mem_commands[] may not strictly be the same
> as CXL_MEM_COMMAND_ID_MAX. E.g. if a new CXL_CMD() is added that is
> guarded by #ifdefs, the array could be shorter. This could lead then
> further to an out-of-bounds array access in cxl_validate_cmd_from_user().

Good catch.

>
> Fix this by forcing the array size to CXL_MEM_COMMAND_ID_MAX. This
> also adds range checks for array items in mem_commands[] at compile
> time.
>
> Signed-off-by: Robert Richter <rrichter@xxxxxxx>

Thanks, applied.