netdev - Re: [PATCH net] sctp: sctp_epaddr_lookup_transport should be protected by rcu_read

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: <20161217.112512.1659218665787719927.davem@davemloft.net>
Date:   Sat, 17 Dec 2016 11:25:12 -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,
        dvyukov@...gle.com
Subject: Re: [PATCH net] sctp: sctp_epaddr_lookup_transport should be
 protected by rcu_read_lock

From: Xin Long <lucien.xin@...il.com>
Date: Thu, 15 Dec 2016 23:00:55 +0800

> Since commit 7fda702f9315 ("sctp: use new rhlist interface on sctp transport
> rhashtable"), sctp has changed to use rhlist_lookup to look up transport, but
> rhlist_lookup doesn't call rcu_read_lock inside, unlike rhashtable_lookup_fast.
> 
> It is called in sctp_epaddr_lookup_transport and sctp_addrs_lookup_transport.
> sctp_addrs_lookup_transport is always in the protection of rcu_read_lock(),
> as __sctp_lookup_association is called in rx path or sctp_lookup_association
> which are in the protection of rcu_read_lock() already.
> 
> But sctp_epaddr_lookup_transport is called by sctp_endpoint_lookup_assoc, it
> doesn't call rcu_read_lock, which may cause "suspicious rcu_dereference_check
> usage' in __rhashtable_lookup.
> 
> This patch is to fix it by adding rcu_read_lock in sctp_endpoint_lookup_assoc
> before calling sctp_epaddr_lookup_transport.
> 
> Fixes: 7fda702f9315 ("sctp: use new rhlist interface on sctp transport rhashtable")
> Reported-by: Dmitry Vyukov <dvyukov@...gle.com>
> Signed-off-by: Xin Long <lucien.xin@...il.com>

Applied.