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: <20150810.132835.492224591558177468.davem@davemloft.net>
Date:	Mon, 10 Aug 2015 13:28:35 -0700 (PDT)
From:	David Miller <davem@...emloft.net>
To:	haokexin@...il.com
Cc:	netdev@...r.kernel.org
Subject: Re: [PATCH net-next] net: fec: fix the race between xmit and bdp
 reclaiming path

From: Kevin Hao <haokexin@...il.com>
Date: Fri,  7 Aug 2015 13:52:37 +0800

> When we transmit a fragmented skb, we may run into a race like the
> following scenario (assume txq->cur_tx is next to txq->dirty_tx):
>            cpu 0                                          cpu 1
>   fec_enet_txq_submit_skb
>     reserve a bdp for the first fragment
>     fec_enet_txq_submit_frag_skb
>        update the bdp for the other fragment
>        update txq->cur_tx
>                                                    fec_enet_tx_queue
>                                                      bdp = fec_enet_get_nextdesc(txq->dirty_tx, fep, queue_id);
>                                                      This bdp is the bdp reserved for the first segment. Given
>                                                      that this bdp BD_ENET_TX_READY bit is not set and txq->cur_tx
>                                                      is already pointed to a bdp beyond this one. We think this is a
>                                                      completed bdp and try to reclaim it.
>     update the bdp for the first segment
>     update txq->cur_tx
> 
> So we shouldn't update the txq->cur_tx until all the update to the
> bdps used for fragments are performed. Also add the corresponding
> memory barrier to guarantee that the update to the bdps, dirty_tx and
> cur_tx performed in the proper order.
> 
> Signed-off-by: Kevin Hao <haokexin@...il.com>

Applied, thanks.
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ