Re: [PATCH 4.19 095/103] bpf: prevent out of bounds speculation on pointer arithmetic

[Jann Horn]

On Tue, Jan 29, 2019 at 12:47 PM Greg Kroah-Hartman
<gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
> 4.19-stable review patch.  If anyone has any objections, please let me know.
>
> ------------------
>
> [ commit 979d63d50c0c0f7bc537bf821e056cc9fe5abd38 upstream ]
>
> Jann reported that the original commit back in b2157399cc98
> ("bpf: prevent out-of-bounds speculation") was not sufficient
> to stop CPU from speculating out of bounds memory access:
> While b2157399cc98 only focussed on masking array map access
> for unprivileged users for tail calls and data access such
> that the user provided index gets sanitized from BPF program
> and syscall side, there is still a more generic form affected
> from BPF programs that applies to most maps that hold user
> data in relation to dynamic map access when dealing with
> unknown scalars or "slow" known scalars as access offset, for
> example:

Is this also going into 4.14 and 4.9? I don't see anything related in
the stable queue or in stable-rc.