From: Jordan Glover <Golden_Miller83@protonmail.ch>
To: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: "sdf@google.com" <sdf@google.com>,
"davem@davemloft.net" <davem@davemloft.net>,
"daniel@iogearbox.net" <daniel@iogearbox.net>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
"bpf@vger.kernel.org" <bpf@vger.kernel.org>,
"kernel-team@fb.com" <kernel-team@fb.com>,
"linux-security-module@vger.kernel.org"
<linux-security-module@vger.kernel.org>,
"acme@redhat.com" <acme@redhat.com>,
"jamorris@linux.microsoft.com" <jamorris@linux.microsoft.com>,
"jannh@google.com" <jannh@google.com>,
"kpsingh@google.com" <kpsingh@google.com>
Subject: Re: [PATCH v5 bpf-next 2/3] bpf: implement CAP_BPF
Date: Tue, 12 May 2020 12:50:05 +0000 [thread overview]
Message-ID: <ZHW2pvJicBV52gi3gjsDNXDF6t7BteEoHKvEGeVueRPPDrEKGR0OMJjTlulOoOrDNNwcK2c7HE1lNEQw8F2G6SEGCCIAekGoY0T_cnJ-oSc=@protonmail.ch> (raw)
In-Reply-To: <20200512023641.jupgmhpliblkli4t@ast-mbp.dhcp.thefacebook.com>
On Tuesday, May 12, 2020 2:36 AM, Alexei Starovoitov <alexei.starovoitov@gmail.com> wrote:
> On Mon, May 11, 2020 at 05:12:10PM -0700, sdf@google.com wrote:
>
> > On 05/08, Alexei Starovoitov wrote:
> >
> > > From: Alexei Starovoitov ast@kernel.org
> > > [..]
> > > @@ -3932,7 +3977,7 @@ SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr
> > > __user *, uattr, unsigned int, siz
> > > union bpf_attr attr;
> > > int err;
> >
> > > - if (sysctl_unprivileged_bpf_disabled && !capable(CAP_SYS_ADMIN))
> > >
> > > - if (sysctl_unprivileged_bpf_disabled && !bpf_capable())
> > > return -EPERM;
> > > This is awesome, thanks for reviving the effort!
> > >
> >
> > One question I have about this particular snippet:
> > Does it make sense to drop bpf_capable checks for the operations
> > that work on a provided fd?
>
> Above snippet is for the case when sysctl switches unpriv off.
> It was a big hammer and stays big hammer.
> I certainly would like to improve the situation, but I suspect
> the folks who turn that sysctl knob on are simply paranoid about bpf
> and no amount of reasoning would turn them around.
>
Without CAP_BPF, sysctl was the only option to keep you safe from flow
of bpf vulns. You didn't had to be paranoid about that.
Jordan
next prev parent reply other threads:[~2020-05-12 12:50 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-08 21:53 [PATCH v5 bpf-next 0/3] Introduce CAP_BPF Alexei Starovoitov
2020-05-08 21:53 ` [PATCH v5 bpf-next 1/3] bpf, capability: " Alexei Starovoitov
2020-05-08 21:53 ` [PATCH v5 bpf-next 2/3] bpf: implement CAP_BPF Alexei Starovoitov
2020-05-12 0:12 ` sdf
2020-05-12 2:36 ` Alexei Starovoitov
2020-05-12 12:50 ` Jordan Glover [this message]
2020-05-12 15:46 ` Alexei Starovoitov
2020-05-12 15:54 ` sdf
2020-05-12 18:39 ` Alexei Starovoitov
2020-05-12 14:35 ` Daniel Borkmann
2020-05-12 18:25 ` Alexei Starovoitov
2020-05-12 20:07 ` Daniel Borkmann
2020-05-12 22:56 ` Alexei Starovoitov
2020-05-12 15:05 ` Daniel Borkmann
2020-05-12 18:29 ` Alexei Starovoitov
2020-05-12 20:09 ` Daniel Borkmann
2020-05-12 20:27 ` Daniel Borkmann
2020-05-12 23:01 ` Alexei Starovoitov
2020-05-08 21:53 ` [PATCH v5 bpf-next 3/3] selftests/bpf: use CAP_BPF and CAP_PERFMON in tests Alexei Starovoitov
2020-05-08 22:45 ` [PATCH v5 bpf-next 0/3] Introduce CAP_BPF Casey Schaufler
2020-05-08 23:00 ` Alexei Starovoitov
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