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
| ||
|
Message-ID: <53CCD2DF.4010307@collabora.co.uk> Date: Mon, 21 Jul 2014 10:44:15 +0200 From: Javier Martinez Canillas <javier.martinez@...labora.co.uk> To: Lars-Peter Clausen <lars@...afoo.de>, Dan Williams <dan.j.williams@...el.com> CC: Vinod Koul <vinod.koul@...el.com>, dmaengine@...r.kernel.org, linux-kernel@...r.kernel.org Subject: Re: [PATCH 1/1] dmaengine: pl330: Check if the DMA descriptor is NULL On 07/21/2014 10:22 AM, Lars-Peter Clausen wrote: > On 07/20/2014 07:58 PM, Javier Martinez Canillas wrote: >> >> If this should not really happen and this patch is only a workaround since the >> bug is elsewhere, please give me some hints and I'll try to fix it properly. I'm >> not familiar with the PL330 DMA controller but just found what was the NULL >> pointer being dereferenced and looked at your changes to see what was different now. > > I think the patch is fine as a quick workaround since it is simple and the > previous commit broke previously working code. > Agreed, it matches what the old code was doing and other code is relying on this behavior so works as a quick fix to avoid the current kernel oops. > The long term fix is to stop calling dma_pl330_rqcb() from > pl330_release_channel(). The first thing is you wouldn't expect any transfer > to be active when the channel is released. And even if it was by accident we > should not call the descriptor callback, but rather but it just back onto > the descriptor pool. Thanks a lot for the clarification. I thought it was something along the lines of not calling the callback from pl330_release_channel() but preferred to not change anything that I could not completely understand its side effects. I'll study the driver more deeply and try to come up with a patch on top of this one that fixes the actual cause rather than the consequence. > > - Lars > Best regards, Javier -- 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/
Powered by blists - more mailing lists