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:   Wed, 8 Jan 2020 17:34:21 -0800
From:   Song Liu <>
To:     John Fastabend <>
Cc:     bpf <>, Networking <>,
        Alexei Starovoitov <>,
        Daniel Borkmann <>
Subject: Re: [bpf PATCH 1/9] bpf: sockmap/tls, during free we may call
 tcp_bpf_unhash() in loop

On Wed, Jan 8, 2020 at 1:14 PM John Fastabend <> wrote:
> When a sockmap is free'd and a socket in the map is enabled with tls
> we tear down the bpf context on the socket, the psock struct and state,
> and then call tcp_update_ulp(). The tcp_update_ulp() call is to inform
> the tls stack it needs to update its saved sock ops so that when the tls
> socket is later destroyed it doesn't try to call the now destroyed psock
> hooks.
> This is about keeping stacked ULPs in good shape so they always have
> the right set of stacked ops.
> However, recently unhash() hook was removed from TLS side. But, the
> sockmap/bpf side is not doing any extra work to update the unhash op
> when is torn down instead expecting TLS side to manage it. So both
> TLS and sockmap believe the other side is managing the op and instead
> no one updates the hook so it continues to point at tcp_bpf_unhash().
> When unhash hook is called we call tcp_bpf_unhash() which detects the
> psock has already been destroyed and calls sk->sk_prot_unhash() which
> calls tcp_bpf_unhash() yet again and so on looping and hanging the core.
> To fix have sockmap tear down logic fixup the stale pointer.
> Fixes: 5d92e631b8be ("net/tls: partially revert fix transition through disconnect with close")
> Reported-by:
> Signed-off-by: John Fastabend <>

Acked-by: Song Liu <>

Powered by blists - more mailing lists