netdev - Re: [PATCH net] tls: fix NULL pointer dereference on poll

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Date:   Mon, 11 Jun 2018 15:27:11 -0700
From:   Dave Watson <davejwatson@...com>
To:     Daniel Borkmann <daniel@...earbox.net>
CC:     <davem@...emloft.net>, <netdev@...r.kernel.org>, <ast@...nel.org>,
        Christoph Hellwig <hch@....de>
Subject: Re: [PATCH net] tls: fix NULL pointer dereference on poll

On 06/11/18 11:22 PM, Daniel Borkmann wrote:
> While hacking on kTLS, I ran into the following panic from an
> unprivileged netserver / netperf TCP session:
> 
>   [...]
> Looks like the recent conversion from poll to poll_mask callback started
> in 152524231023 ("net: add support for ->poll_mask in proto_ops") missed
> to eventually convert kTLS, too: TCP's ->poll was converted over to the
> ->poll_mask in commit 2c7d3dacebd4 ("net/tcp: convert to ->poll_mask")
> and therefore kTLS wrongly saved the ->poll old one which is now NULL.
> 
> Convert kTLS over to use ->poll_mask instead. Also instead of POLLIN |
> POLLRDNORM use the proper EPOLLIN | EPOLLRDNORM bits as the case in
> tcp_poll_mask() as well that is mangled here.

Thanks, was just trying to bisect this myself. Works for me. 

Tested-by: Dave Watson <davejwatson@...com>

> Fixes: 2c7d3dacebd4 ("net/tcp: convert to ->poll_mask")
> Signed-off-by: Daniel Borkmann <daniel@...earbox.net>
> Cc: Christoph Hellwig <hch@....de>
> Cc: Dave Watson <davejwatson@...com>