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  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:   Thu, 15 Oct 2020 13:04:39 +0200
From:   Jakub Sitnicki <jakub@...udflare.com>
To:     John Fastabend <john.fastabend@...il.com>
Cc:     Alex Dewar <alex.dewar90@...il.com>,
        Daniel Borkmann <daniel@...earbox.net>,
        Lorenz Bauer <lmb@...udflare.com>,
        "David S. Miller" <davem@...emloft.net>,
        Jakub Kicinski <kuba@...nel.org>,
        Alexei Starovoitov <ast@...nel.org>,
        Martin KaFai Lau <kafai@...com>,
        Song Liu <songliubraving@...com>, Yonghong Song <yhs@...com>,
        Andrii Nakryiko <andrii@...nel.org>,
        KP Singh <kpsingh@...omium.org>, netdev@...r.kernel.org,
        bpf@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] net: sockmap: Don't call bpf_prog_put() on NULL pointer

On Thu, Oct 15, 2020 at 06:43 AM CEST, John Fastabend wrote:

[...]

> Jakub, any opinions on if we should just throw an error if users try to
> add a sock to a map with a parser but no verdict? At the moment we fall
> through and add the socket, but it wont do any receive parsing/verdict.
> At the moment I think its fine with above fix. The useful cases for RX
> are parser+verdict, verdict, and empty. Where empty is just used for
> redirects or other socket account tricks. Just something to keep in mind.

IMO we should not fail because map updates can interleave with sk_skb
prog attachments, like so:

	update_map(map_fd, sock_fd);
	attach_prog(parser_fd, map_fd, BPF_SK_SKB_STREAM_PARSER);
	update_map(map_fd, sock_fd); // OK
	attach_prog(verdict_fd, map_fd, BPF_SK_SKB_STREAM_VERDICT);
	update_map(map_fd, sock_fd);

In practice, I would expect one process/thread to attach the programs,
while another is allowed to update the map at the same time.

Powered by blists - more mailing lists