linux-kernel - Re: [PATCH 3/3] net: fix iteration for sctp transport seq

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, 5 Feb 2021 11:32:40 -0300
From:   Marcelo Ricardo Leitner <marcelo.leitner@...il.com>
To:     NeilBrown <neilb@...e.de>
Cc:     Andrew Morton <akpm@...ux-foundation.org>,
        Alexander Viro <viro@...iv.linux.org.uk>,
        Vlad Yasevich <vyasevich@...il.com>,
        Neil Horman <nhorman@...driver.com>,
        Xin Long <lucien.xin@...il.com>, linux-kernel@...r.kernel.org,
        "David S. Miller" <davem@...emloft.net>,
        linux-sctp@...r.kernel.org, netdev@...r.kernel.org
Subject: Re: [PATCH 3/3] net: fix iteration for sctp transport seq_files

On Fri, Feb 05, 2021 at 11:36:30AM +1100, NeilBrown wrote:
> The sctp transport seq_file iterators take a reference to the transport
> in the ->start and ->next functions and releases the reference in the
> ->show function.  The preferred handling for such resources is to
> release them in the subsequent ->next or ->stop function call.
> 
> Since Commit 1f4aace60b0e ("fs/seq_file.c: simplify seq_file iteration
> code and interface") there is no guarantee that ->show will be called
> after ->next, so this function can now leak references.
> 
> So move the sctp_transport_put() call to ->next and ->stop.
> 
> Fixes: 1f4aace60b0e ("fs/seq_file.c: simplify seq_file iteration code and interface")
> Reported-by: Xin Long <lucien.xin@...il.com>
> Signed-off-by: NeilBrown <neilb@...e.de>

Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@...il.com>