From: Kumar Kartikeya Dwivedi <memxor@gmail.com>
To: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: bpf@vger.kernel.org, "Alexei Starovoitov" <ast@kernel.org>,
"Andrii Nakryiko" <andrii@kernel.org>,
"Daniel Borkmann" <daniel@iogearbox.net>,
"Pablo Neira Ayuso" <pablo@netfilter.org>,
"Florian Westphal" <fw@strlen.de>,
"Jesper Dangaard Brouer" <brouer@redhat.com>,
"Toke Høiland-Jørgensen" <toke@redhat.com>,
"Lorenzo Bianconi" <lorenzo@kernel.org>,
netdev@vger.kernel.org, netfilter-devel@vger.kernel.org
Subject: Re: [PATCH bpf-next v7 04/13] bpf: Add support for forcing kfunc args to be trusted
Date: Fri, 22 Jul 2022 12:26:11 +0200 [thread overview]
Message-ID: <CAP01T77M27ZxZ-_oMujCCpCkSYJ9iMnm4EHTNgTe2odbCfPt2w@mail.gmail.com> (raw)
In-Reply-To: <20220722041056.r2ozhs4p3s7mt7go@macbook-pro-3.dhcp.thefacebook.com>
On Fri, 22 Jul 2022 at 06:11, Alexei Starovoitov
<alexei.starovoitov@gmail.com> wrote:
>
> On Thu, Jul 21, 2022 at 03:42:36PM +0200, Kumar Kartikeya Dwivedi wrote:
> > +/* Trusted arguments are those which are meant to be referenced arguments with
> > + * unchanged offset. It is used to enforce that pointers obtained from acquire
> > + * kfuncs remain unmodified when being passed to helpers taking trusted args.
> > + *
> > + * Consider
> > + * struct foo {
> > + * int data;
> > + * struct foo *next;
> > + * };
> > + *
> > + * struct bar {
> > + * int data;
> > + * struct foo f;
> > + * };
> > + *
> > + * struct foo *f = alloc_foo(); // Acquire kfunc
> > + * struct bar *b = alloc_bar(); // Acquire kfunc
> > + *
> > + * If a kfunc set_foo_data() wants to operate only on the allocated object, it
> > + * will set the KF_TRUSTED_ARGS flag, which will prevent unsafe usage like:
> > + *
> > + * set_foo_data(f, 42); // Allowed
> > + * set_foo_data(f->next, 42); // Rejected, non-referenced pointer
> > + * set_foo_data(&f->next, 42);// Rejected, referenced, but bad offset
> > + * set_foo_data(&b->f, 42); // Rejected, referenced, but wrong type
>
> I think you meant to swap above two comments ?
> That's what I did while applying.
>
> Also fixed typo in Fixes tag in patch 13. It was missing a letter in sha.
>
> Since there are 3 other pending patchsets in patchwork that add new kfuncs
> this cleanup of kfunc registration couldn't have come at better time.
>
> Thank you for doing this work.
Thank you for doing the fixups!
next prev parent reply other threads:[~2022-07-22 10:28 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-21 13:42 [PATCH bpf-next v7 00/13] New nf_conntrack kfuncs for insertion, changing timeout, status Kumar Kartikeya Dwivedi
2022-07-21 13:42 ` [PATCH bpf-next v7 01/13] bpf: Introduce 8-byte BTF set Kumar Kartikeya Dwivedi
2022-07-21 13:42 ` [PATCH bpf-next v7 02/13] tools/resolve_btfids: Add support for 8-byte BTF sets Kumar Kartikeya Dwivedi
2022-07-21 20:51 ` Jiri Olsa
2022-07-21 13:42 ` [PATCH bpf-next v7 03/13] bpf: Switch to new kfunc flags infrastructure Kumar Kartikeya Dwivedi
2022-07-21 13:42 ` [PATCH bpf-next v7 04/13] bpf: Add support for forcing kfunc args to be trusted Kumar Kartikeya Dwivedi
2022-07-22 4:10 ` Alexei Starovoitov
2022-07-22 10:26 ` Kumar Kartikeya Dwivedi [this message]
2022-07-25 9:52 ` Roberto Sassu
2022-07-26 9:30 ` Kumar Kartikeya Dwivedi
2022-07-26 10:02 ` Roberto Sassu
2022-07-26 12:55 ` Kumar Kartikeya Dwivedi
2022-07-26 12:58 ` Roberto Sassu
2022-07-21 13:42 ` [PATCH bpf-next v7 05/13] bpf: Add documentation for kfuncs Kumar Kartikeya Dwivedi
2022-07-21 13:42 ` [PATCH bpf-next v7 06/13] net: netfilter: Deduplicate code in bpf_{xdp,skb}_ct_lookup Kumar Kartikeya Dwivedi
2022-07-21 13:42 ` [PATCH bpf-next v7 07/13] net: netfilter: Add kfuncs to allocate and insert CT Kumar Kartikeya Dwivedi
2022-07-22 9:02 ` Pablo Neira Ayuso
2022-07-22 9:39 ` Kumar Kartikeya Dwivedi
2022-07-23 7:50 ` Pablo Neira Ayuso
2022-07-25 8:52 ` Kumar Kartikeya Dwivedi
2022-07-21 13:42 ` [PATCH bpf-next v7 08/13] net: netfilter: Add kfuncs to set and change CT timeout Kumar Kartikeya Dwivedi
2022-07-21 13:42 ` [PATCH bpf-next v7 09/13] net: netfilter: Add kfuncs to set and change CT status Kumar Kartikeya Dwivedi
2022-07-21 13:42 ` [PATCH bpf-next v7 10/13] selftests/bpf: Add verifier tests for trusted kfunc args Kumar Kartikeya Dwivedi
2022-07-21 13:42 ` [PATCH bpf-next v7 11/13] selftests/bpf: Add tests for new nf_conntrack kfuncs Kumar Kartikeya Dwivedi
2022-07-21 13:42 ` [PATCH bpf-next v7 12/13] selftests/bpf: Add negative " Kumar Kartikeya Dwivedi
2022-07-21 13:42 ` [PATCH bpf-next v7 13/13] selftests/bpf: Fix test_verifier failed test in unprivileged mode Kumar Kartikeya Dwivedi
2022-07-21 17:28 ` [PATCH bpf-next v7 00/13] New nf_conntrack kfuncs for insertion, changing timeout, status Zvi Effron
2022-07-21 18:01 ` Kumar Kartikeya Dwivedi
2022-07-22 4:10 ` patchwork-bot+netdevbpf
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