[PATCH] netlabel: fix shift wrapping bug in netlbl_catmap_setlong()

Paul Moore paul at paul-moore.com
Thu Jun 8 18:57:41 UTC 2023


On Thu, Jun 8, 2023 at 9:58 AM Dmitry Mastykin <dmastykin at astralinux.ru> wrote:
>
> There is a shift wrapping bug in this code on 32-bit architectures.
> NETLBL_CATMAP_MAPTYPE is u64, bitmap is unsigned long.
> Every second 32-bit word of catmap becomes corrupted.
>
> Signed-off-by: Dmitry Mastykin <dmastykin at astralinux.ru>
> ---
>  net/netlabel/netlabel_kapi.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)

Thanks Dmitry.

Acked-by: Paul Moore <paul at paul-moore.com>

> diff --git a/net/netlabel/netlabel_kapi.c b/net/netlabel/netlabel_kapi.c
> index 54c083003947..27511c90a26f 100644
> --- a/net/netlabel/netlabel_kapi.c
> +++ b/net/netlabel/netlabel_kapi.c
> @@ -857,7 +857,8 @@ int netlbl_catmap_setlong(struct netlbl_lsm_catmap **catmap,
>
>         offset -= iter->startbit;
>         idx = offset / NETLBL_CATMAP_MAPSIZE;
> -       iter->bitmap[idx] |= bitmap << (offset % NETLBL_CATMAP_MAPSIZE);
> +       iter->bitmap[idx] |= (NETLBL_CATMAP_MAPTYPE)bitmap
> +                            << (offset % NETLBL_CATMAP_MAPSIZE);
>
>         return 0;
>  }
> --
> 2.30.2

-- 
paul-moore.com



More information about the Linux-security-module-archive mailing list