From: Johannes Berg <johannes@sipsolutions.net>
To: Yogesh Ashok Powar <yogeshp@marvell.com>
Cc: <linux-wireless@vger.kernel.org>,
"John W. Linville" <linville@tuxdriver.com>,
Andreas Hartmann <andihartmann@01019freenet.de>
Subject: Re: [PATCH 2/2] mac80211: Fixing Races for skipping tailroom reservation
Date: Thu, 16 Jun 2011 17:36:24 +0200 [thread overview]
Message-ID: <d38dc36c1ab9a4bd819b9bcbbda181da@secure.sipsolutions.net> (raw)
In-Reply-To: <20110616102707.GB24458@hertz.marvell.com>
On Thu, 16 Jun 2011 15:57:08 +0530, Yogesh Ashok Powar wrote:
> Following warning was observed after the commit
> aac6af5534fade2b18682a0b9efad1a6c04c34c6
>
>>WARNING: at net/mac80211/wpa.c:397 ccmp_encrypt_skb+0xc4/0x1f0
>
> Consider a scenario where reserving skb tailroom is skipped
> because software encryption is not enabled. SW encryption
> can be disabled because of a) All the keys are hardware
> planted b) No key has been created. But, before actual
> transmit if hardware encryption is disabled or software
> encryption is started, there will not be enough tailroom
> space to accommodate the sw crypto's MMIC or IV and
> WARN_ON will be hit.
>
> This race between updations of hw keys and skipping & using
> tailroom, is fixed by protecting critical regions (code
> accessing crypto_tx_tailroom_needed_cnt and code from
> tailroom skipping to skb_put for IV or MMIC) with the
> spinlock.
Haha, good joke. You've got to be kidding. NACK. No inserting spinlocks
into the TX/RX paths.
johannes
next prev parent reply other threads:[~2011-06-16 15:36 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-06-16 10:21 [PATCH 0/2] mac80211: Fixing races for hw crypto skipping tailroom Yogesh Ashok Powar
2011-06-16 10:25 ` [PATCH 1/2] Revert "Revert "mac80211: Skip tailroom reservation for full HW-crypto devices"" Yogesh Ashok Powar
2011-06-16 10:27 ` [PATCH 2/2] mac80211: Fixing Races for skipping tailroom reservation Yogesh Ashok Powar
2011-06-16 15:36 ` Johannes Berg [this message]
2011-06-17 13:25 ` Yogesh Ashok Powar
2011-06-17 17:24 ` Johannes Berg
2011-06-20 14:30 ` Yogesh Ashok Powar
2011-06-20 15:29 ` Johannes Berg
2011-06-20 16:49 ` Yogesh Powar
2011-06-20 17:29 ` Johannes Berg
2011-06-21 13:03 ` Yogesh Ashok Powar
2011-06-21 13:43 ` Johannes Berg
2011-06-21 14:10 ` Yogesh Ashok Powar
2011-06-21 14:40 ` Johannes Berg
2011-06-21 16:33 ` Yogesh Ashok Powar
2011-06-21 17:44 ` Andreas Hartmann
2011-06-22 7:17 ` Yogesh Ashok Powar
2011-06-22 12:31 ` Yogesh Ashok Powar
2011-06-22 12:49 ` Johannes Berg
2011-06-22 12:58 ` Yogesh Ashok Powar
2011-06-22 13:12 ` Johannes Berg
2011-06-23 11:52 ` Yogesh Powar
2011-06-24 9:04 ` yogeshp
2011-06-25 13:07 ` Johannes Berg
2011-06-27 6:02 ` [PATCH] nl80211: use netlink consistent dump feature for BSS dumps Walter Goldens
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