Re: [PATCH net] netfilter: nf_tables: fix pointer math issue in nft_byteorder_eval()

From: Florian Westphal
Date: Tue Feb 06 2024 - 06:31:19 EST


Michal Kubecek <mkubecek@xxxxxxx> wrote:
> I stumbled upon this when the issue got a CVE id (sigh) and I share
> Andrea's (Cc-ed) concern that the fix is incomplete. While the fix,
> commit c301f0981fdd ("netfilter: nf_tables: fix pointer math issue in
> nft_byteorder_eval()") now, fixes the destination side, src is still
> a pointer to u32, i.e. we are reading 64-bit values with relative
> offsets which are multiples of 32 bits.
>
> Shouldn't we fix this as well, e.g. like indicated below?

No, please remove multi-elem support instead, nothing uses this feature.