From: John Fastabend <john.fastabend@gmail.com>
To: "liujian (CE)" <liujian56@huawei.com>, Martin KaFai Lau <kafai@fb.com>
Cc: "ast@kernel.org" <ast@kernel.org>,
"daniel@iogearbox.net" <daniel@iogearbox.net>,
"andrii@kernel.org" <andrii@kernel.org>,
"songliubraving@fb.com" <songliubraving@fb.com>,
"yhs@fb.com" <yhs@fb.com>,
"john.fastabend@gmail.com" <john.fastabend@gmail.com>,
"kpsingh@kernel.org" <kpsingh@kernel.org>,
"davem@davemloft.net" <davem@davemloft.net>,
"kuba@kernel.org" <kuba@kernel.org>,
"sdf@google.com" <sdf@google.com>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
"bpf@vger.kernel.org" <bpf@vger.kernel.org>
Subject: RE: [PATCH bpf-next] net: Use skb->len to check the validity of the parameters in bpf_skb_load_bytes
Date: Tue, 15 Mar 2022 21:00:09 -0700 [thread overview]
Message-ID: <623160c966680_94df20819@john.notmuch> (raw)
In-Reply-To: <4f937ace70a3458580c6242fa68ea549@huawei.com>
liujian (CE) wrote:
>
>
> > -----Original Message-----
> > From: Martin KaFai Lau [mailto:kafai@fb.com]
> > Sent: Wednesday, March 16, 2022 3:58 AM
> > To: liujian (CE) <liujian56@huawei.com>
> > Cc: ast@kernel.org; daniel@iogearbox.net; andrii@kernel.org;
> > songliubraving@fb.com; yhs@fb.com; john.fastabend@gmail.com;
> > kpsingh@kernel.org; davem@davemloft.net; kuba@kernel.org;
> > sdf@google.com; netdev@vger.kernel.org; bpf@vger.kernel.org
> > Subject: Re: [PATCH bpf-next] net: Use skb->len to check the validity of the
> > parameters in bpf_skb_load_bytes
> >
> > On Tue, Mar 15, 2022 at 08:39:16PM +0800, Liu Jian wrote:
> > > The data length of skb frags + frag_list may be greater than 0xffff,
> > > so here use skb->len to check the validity of the parameters.
> > What is the use case that needs to look beyond 0xffff ?
> I use sockmap with strparser, the stm->strp.offset (the begin of one
> application layer protocol message) maybe beyond 0xffff, but i need
> load the message head to do something.
This would explain skb_load_bytes but not the other two right? Also
if we are doing this why not just remove those two checks in
flow_dissector_load() I think skb_header_pointer() does duplicate
checks. Please check.
next prev parent reply other threads:[~2022-03-16 4:00 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-15 12:39 [PATCH bpf-next] net: Use skb->len to check the validity of the parameters in bpf_skb_load_bytes Liu Jian
2022-03-15 19:58 ` Martin KaFai Lau
2022-03-16 1:09 ` liujian (CE)
2022-03-16 4:00 ` John Fastabend [this message]
2022-03-16 13:08 ` liujian (CE)
2022-03-16 15:09 ` Stanislav Fomichev
2022-03-17 14:08 ` liujian (CE)
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