linux-kernel - Re: [TIP] BUG kmalloc-4096: Poison overwritten (ath5k_rx_skb

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]

Message-ID: <49A46AD4.3060007@gmail.com>
Date:	Tue, 24 Feb 2009 22:47:00 +0100
From:	Jiri Slaby <jirislaby@...il.com>
To:	Bob Copeland <me@...copeland.com>
CC:	Nick Kossifidis <mickflemm@...il.com>,
	Sitsofe Wheeler <sitsofe@...oo.com>,
	Frederic Weisbecker <fweisbec@...il.com>,
	linux-kernel@...r.kernel.org, linux-wireless@...r.kernel.org,
	ath5k-devel@...ema.h4ckr.net,
	"Luis R. Rodriguez" <lrodriguez@...eros.com>
Subject: Re: [TIP] BUG kmalloc-4096: Poison overwritten (ath5k_rx_skb_alloc)

On 24.2.2009 14:58, Bob Copeland wrote:
> On Tue, Feb 24, 2009 at 01:08:03AM +0200, Nick Kossifidis wrote:
>> He does an extra check...
>>
>> 	/*
>> 	 * Given the use of a self-linked tail be very sure that the hw is
>> 	 * done with this descriptor; the hw may have done this descriptor
>> 	 * once and picked it up again...make sure the hw has moved on.
>> 	 */
>> 	if ((ands->ds_rxstatus1&AR_Done) == 0&&  OS_REG_READ(ah, AR_RXDP) == pa)
>> 		return HAL_EINPROGRESS;
>
> Sounds like we definitely need that.If the hw uses up all the dma buffers
> in one go, there's a good chance we can send the skb to mac80211 while
> the hardware is still using it.  I guess an easy way to test would be to
> set the max rx buffers to 3 or so and watch the fireworks.

I added a check for this in rx tasklet some time ago, because I hit it. 
So no fireworks really should happen ;).

And yes, we ought to use this much better test (I knew nothing about 
AR_RXDP reg) than mine.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/