Re: [PATCH net-next v2 2/2] bpf: Extend check_uarg_tail_zero() checks

From: David Miller
Date: Tue Aug 08 2017 - 21:11:42 EST


From: Mickaël Salaün <mic@xxxxxxxxxxx>
Date: Mon, 7 Aug 2017 20:45:20 +0200

> The function check_uarg_tail_zero() was created from bpf(2) for
> BPF_OBJ_GET_INFO_BY_FD without taking the access_ok() nor the PAGE_SIZE
> checks. Make this checks more generally available while unlikely to be
> triggered, extend the memory range check and add an explanation
> including why the ToCToU should not be a security concern.
>
> Signed-off-by: Mickaël Salaün <mic@xxxxxxxxxxx>
> Acked-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
> Cc: Alexei Starovoitov <ast@xxxxxxxxxx>
> Cc: David S. Miller <davem@xxxxxxxxxxxxx>
> Cc: Kees Cook <keescook@xxxxxxxxxxxx>
> Cc: Martin KaFai Lau <kafai@xxxxxx>
> Link: https://lkml.kernel.org/r/CAGXu5j+vRGFvJZmjtAcT8Hi8B+Wz0e1b6VKYZHfQP_=DXzC4CQ@xxxxxxxxxxxxxx

Applied.