From: Patrick McHardy <kaber@trash.net>
To: Jan Engelhardt <jengelh@medozas.de>
Cc: Adam Nielsen <a.nielsen@shikadi.net>,
Netfilter Developer Mailing List
<netfilter-devel@vger.kernel.org>
Subject: Re: [PATCH v2] Add refcounts to LED target
Date: Wed, 07 Apr 2010 18:15:19 +0200 [thread overview]
Message-ID: <4BBCAF97.6040806@trash.net> (raw)
In-Reply-To: <alpine.LSU.2.01.1004041327160.22215@obet.zrqbmnf.qr>
Jan Engelhardt wrote:
> On Sunday 2010-03-28 03:25, Adam Nielsen wrote:
>
>> Add reference counting to the LED target so that multiple targets sharing the
>> same trigger don't cause any problems.
>
> I also noticed one another thing: you don't increase the refcount while
> xt_led_mutex is held. That means it is theoretically possible that you
> do a lookup, then a destructor runs and frees the object, leading to
> ++ledinternal->refcnt dereference an illegal ledinternal.
Indeed, I also noticed this. Basically, you need to make sure that
- the lookup and refcnt increase is atomic,
- the refcnt decrease and list deletion is atomic
- the lookup and list insertion is atomic (in case no trigger exists)
The remaining parts look fine to me, thanks.
next prev parent reply other threads:[~2010-04-07 16:15 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-05-24 1:46 Avoiding multiple calls to xt_target.checkentry Adam Nielsen
2009-05-24 7:34 ` Jan Engelhardt
2009-05-27 23:07 ` Adam Nielsen
2009-05-28 21:06 ` Jan Engelhardt
2009-06-03 9:25 ` Patrick McHardy
2009-06-03 11:03 ` Adam Nielsen
2009-11-05 15:00 ` Patrick McHardy
2009-11-05 18:40 ` Jan Engelhardt
2009-11-05 18:43 ` Patrick McHardy
2009-11-05 22:04 ` Adam Nielsen
2009-11-06 14:56 ` Patrick McHardy
2009-11-29 1:43 ` [PATCH] Add refcounts to LED target Adam Nielsen
2009-11-29 10:12 ` Jan Engelhardt
2009-11-29 11:33 ` Adam Nielsen
2009-11-29 15:49 ` Jan Engelhardt
2009-12-01 10:05 ` Patrick McHardy
2009-12-06 10:09 ` Adam Nielsen
2009-12-06 13:24 ` Patrick McHardy
2010-03-25 14:01 ` Patrick McHardy
2010-03-25 14:05 ` Jan Engelhardt
2010-03-25 14:08 ` Patrick McHardy
2010-03-27 4:05 ` Adam Nielsen
2010-03-27 11:15 ` Jan Engelhardt
2010-03-27 11:39 ` Adam Nielsen
2010-03-27 11:55 ` Jan Engelhardt
2010-03-28 1:25 ` [PATCH v2] " Adam Nielsen
2010-04-04 11:30 ` Jan Engelhardt
2010-04-07 16:15 ` Patrick McHardy [this message]
2010-04-08 3:03 ` [PATCH v3] " Adam Nielsen
2010-04-08 11:33 ` Patrick McHardy
2010-04-08 12:45 ` Jan Engelhardt
2010-04-08 12:57 ` Patrick McHardy
2010-04-08 23:06 ` [PATCH v4] " Adam Nielsen
2010-04-09 14:52 ` Patrick McHardy
2010-04-08 21:07 ` [PATCH v3] " Florian Westphal
2010-04-08 22:45 ` Adam Nielsen
2010-03-27 18:42 ` [PATCH] " Jan Engelhardt
2010-03-28 1:58 ` Adam Nielsen
2010-04-04 11:59 ` Jan Engelhardt
2010-04-08 3:15 ` input-layer LEDs as LED-class devices (was: Add refcounts to LED target) Adam Nielsen
2010-04-08 8:03 ` Jan Engelhardt
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