netdev - Re: [PATCH net 1/3] sctp: hold transport instead of assoc in sctp

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, 28 Oct 2016 10:01:45 -0400
From:   Neil Horman <nhorman@...driver.com>
To:     Xin Long <lucien.xin@...il.com>
Cc:     network dev <netdev@...r.kernel.org>, linux-sctp@...r.kernel.org,
        davem@...emloft.net,
        Marcelo Ricardo Leitner <marcelo.leitner@...il.com>,
        Vlad Yasevich <vyasevich@...il.com>, daniel@...earbox.net
Subject: Re: [PATCH net 1/3] sctp: hold transport instead of assoc in
 sctp_diag

On Fri, Oct 28, 2016 at 06:10:52PM +0800, Xin Long wrote:
> In sctp_transport_lookup_process(), Commit 1cceda784980 ("sctp: fix
> the issue sctp_diag uses lock_sock in rcu_read_lock") moved cb() out
> of rcu lock, but it put transport and hold assoc instead, and ignore
> that cb() still uses transport. It may cause a use-after-free issue.
> 
> This patch is to hold transport instead of assoc there.
> 
> Fixes: 1cceda784980 ("sctp: fix the issue sctp_diag uses lock_sock in rcu_read_lock")
> Signed-off-by: Xin Long <lucien.xin@...il.com>
> ---
>  net/sctp/socket.c | 5 +----
>  1 file changed, 1 insertion(+), 4 deletions(-)
> 
> diff --git a/net/sctp/socket.c b/net/sctp/socket.c
> index 9fbb6fe..71b75f9 100644
> --- a/net/sctp/socket.c
> +++ b/net/sctp/socket.c
> @@ -4480,12 +4480,9 @@ int sctp_transport_lookup_process(int (*cb)(struct sctp_transport *, void *),
>  	if (!transport || !sctp_transport_hold(transport))
>  		goto out;
>  
> -	sctp_association_hold(transport->asoc);
> -	sctp_transport_put(transport);
> -
>  	rcu_read_unlock();
>  	err = cb(transport, p);
> -	sctp_association_put(transport->asoc);
> +	sctp_transport_put(transport);
>  
>  out:
>  	return err;
> -- 
> 2.1.0
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-sctp" in
> the body of a message to majordomo@...r.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 
Acked-by: Neil Horman <nhorman@...driver.com>