netdev - Re: [PATCH v2 net] bpf: introduce BPF_F_ALLOW

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-Id: <20170212.215241.895807377087801300.davem@davemloft.net>
Date:   Sun, 12 Feb 2017 21:52:41 -0500 (EST)
From:   David Miller <davem@...emloft.net>
To:     ast@...com
Cc:     daniel@...earbox.net, dsa@...ulusnetworks.com, daniel@...que.org,
        tj@...nel.org, luto@...capital.net, netdev@...r.kernel.org
Subject: Re: [PATCH v2 net] bpf: introduce BPF_F_ALLOW_OVERRIDE flag

From: Alexei Starovoitov <ast@...com>
Date: Fri, 10 Feb 2017 20:28:24 -0800

> If BPF_F_ALLOW_OVERRIDE flag is used in BPF_PROG_ATTACH command
> to the given cgroup the descendent cgroup will be able to override
> effective bpf program that was inherited from this cgroup.
> By default it's not passed, therefore override is disallowed.
> 
> Examples:
> 1.
> prog X attached to /A with default
> prog Y fails to attach to /A/B and /A/B/C
> Everything under /A runs prog X
> 
> 2.
> prog X attached to /A with allow_override.
> prog Y fails to attach to /A/B with default (non-override)
> prog M attached to /A/B with allow_override.
> Everything under /A/B runs prog M only.
> 
> 3.
> prog X attached to /A with allow_override.
> prog Y fails to attach to /A with default.
> The user has to detach first to switch the mode.
> 
> In the future this behavior may be extended with a chain of
> non-overridable programs.
> 
> Also fix the bug where detach from cgroup where nothing is attached
> was not throwing error. Return ENOENT in such case.
> 
> Add several testcases and adjust libbpf.
> 
> Fixes: 3007098494be ("cgroup: add support for eBPF programs")
> Signed-off-by: Alexei Starovoitov <ast@...nel.org>

Applied.