netdev - Re: Handling of EAGAIN from BPF verifier

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: <20190107211340.i77lk5ubimxbh7jq@ast-mbp>
Date:   Mon, 7 Jan 2019 13:13:41 -0800
From:   Alexei Starovoitov <alexei.starovoitov@...il.com>
To:     Lorenz Bauer <lmb@...udflare.com>
Cc:     Alexei Starovoitov <ast@...nel.org>, netdev@...r.kernel.org,
        Daniel Borkmann <daniel@...earbox.net>
Subject: Re: Handling of EAGAIN from BPF verifier

On Mon, Jan 07, 2019 at 03:07:09PM +0000, Lorenz Bauer wrote:
> Hi,
> 
> Commit "bpf: check pending signals while verifying programs" makes the
> bpf syscall return EAGAIN for BPF_PROG_LOAD. How should user space
> react to this? The error sounds like it should retry, but I couldn't
> find the corresponding code for this in libbpf.

since the user process was suspended while loading the loader should retry.
I think libbpf should do it unconditionally in bpf_load_program_xattr().
Patches are welcome :)