Re: [PATCH bpf] libbpf: fix passing uninitialized bytes to setsockopt

[Ilya Maximets]

On 13.10.2019 6:59, Alexei Starovoitov wrote:
> On Sat, Oct 12, 2019 at 9:52 PM Ilya Maximets <i.maximets@xxxxxxx> wrote:
> > 'struct xdp_umem_reg' has 4 bytes of padding at the end that makes
> > valgrind complain about passing uninitialized stack memory to the
> > syscall:
> >
> >    Syscall param socketcall.setsockopt() points to uninitialised byte(s)
> >      at 0x4E7AB7E: setsockopt (in /usr/lib64/libc-2.29.so)
> >      by 0x4BDE035: xsk_umem__create@@LIBBPF_0.0.4 (xsk.c:172)
> >    Uninitialised value was created by a stack allocation
> >      at 0x4BDDEBA: xsk_umem__create@@LIBBPF_0.0.4 (xsk.c:140)
> >
> > Padding bytes appeared after introducing of a new 'flags' field.
> >
> > Fixes: 10d30e301732 ("libbpf: add flags to umem config")
> > Signed-off-by: Ilya Maximets <i.maximets@xxxxxxx>
>
> Something is not right with (e|g)mail.
> This is 3rd email I got with the same patch.
> First one (the one that was applied) was 3 days ago.

I'm sorry.  I don't know why the mail server started re-sending
these e-mails.  I'm receiving them too.

That is strange.

Best regards, Ilya Maximets.