netdev - Re: [PATCH net] sctp: check duplicate node before inserting a new transport

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

Date:   Fri, 17 Feb 2017 15:19:07 -0500 (EST)
From:   David Miller <davem@...emloft.net>
To:     lucien.xin@...il.com
Cc:     netdev@...r.kernel.org, linux-sctp@...r.kernel.org,
        marcelo.leitner@...il.com, nhorman@...driver.com,
        vyasevich@...il.com
Subject: Re: [PATCH net] sctp: check duplicate node before inserting a new
 transport

From: Xin Long <lucien.xin@...il.com>
Date: Fri, 17 Feb 2017 16:35:24 +0800


> +	list = rhltable_lookup(&sctp_transport_hashtable, &arg,
> +			       sctp_hash_params);
> +
> +	rhl_for_each_entry_rcu(transport, tmp, list, node)
> +		if (transport->asoc->ep == t->asoc->ep) {
> +			err = -EEXIST;
> +			goto out;
> +		}
> +
>  	err = rhltable_insert_key(&sctp_transport_hashtable, &arg,
>  				  &t->node, sctp_hash_params);
> +
> +out:

Well, what if another thread of control inserts a matching transport
after you've checked the list but before rhltable_insert_key() does
it's work?

What write side lock is being held to protect the table from
modifications here?