Alexei Starovoitov <alexei.starovoi...@gmail.com> [Fri, 2019-04-12 09:20 -0700]:
> On Fri, Apr 12, 2019 at 3:56 AM Tetsuo Handa
> <penguin-ker...@i-love.sakura.ne.jp> wrote:
> >
> > KMSAN will complain if valid address length passed to bpf_bind() is
> > shorter than sizeof("struct sockaddr"->sa_family) bytes.
> >
> > Signed-off-by: Tetsuo Handa <penguin-ker...@i-love.sakura.ne.jp>
> > ---
> > net/core/filter.c | 2 ++
> > 1 file changed, 2 insertions(+)
> >
> > diff --git a/net/core/filter.c b/net/core/filter.c
> > index 41f633cf4fc1..b9089fda4367 100644
> > --- a/net/core/filter.c
> > +++ b/net/core/filter.c
> > @@ -4458,6 +4458,8 @@ BPF_CALL_3(bpf_bind, struct bpf_sock_addr_kern *,
> > ctx, struct sockaddr *, addr,
> > * Only binding to IP is supported.
> > */
> > err = -EINVAL;
> > + if (addr_len < offsetofend(struct sockaddr, sa_family))
> > + return err;
>
> the verifier will check that addr_len is not zero,
> but it can be one byte, so it's a good check.
> Thanks!
True, I missed this corner-case. Thanks for fixing.
Acked-by: Andrey Ignatov <r...@fb.com>
> > if (addr->sa_family == AF_INET) {
> > if (addr_len < sizeof(struct sockaddr_in))
> > return err;
> > --
> > 2.16.5
> >
--
Andrey Ignatov
