linux-kernel - Re: [patch 6/7] SDHCI: Check DMA for overruns at end of transfer

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: <20081114230026.18513b8a@mjolnir.drzeus.cx>
Date:	Fri, 14 Nov 2008 23:00:26 +0100
From:	Pierre Ossman <drzeus-mmc@...eus.cx>
To:	Ben Dooks <ben-linux@...ff.org>
Cc:	linux-kernel@...r.kernel.org, sdhci-devel@...t.drzeus.cx,
	Ben Dooks <ben-linux@...ff.org>
Subject: Re: [patch 6/7] SDHCI: Check DMA for overruns at end of transfer

On Mon, 03 Nov 2008 20:09:50 +0000
Ben Dooks <ben-linux@...ff.org> wrote:

> At the end of a transfer, check that the DMA engine in the
> SDHCI controller actually did what it was meant to and didn't
> overrun the end of the buffer.
> 
> This seems to be triggered by a timeout during an CMD25 (multiple block         
> write) to a card. The mmc_block module then issues a command to find out        
> how much data was moved and this seems to end up triggering this DMA            
> check. The result is the card's queue generates an OOPS as the stack has        
> been trampled on due to the extra data transfered.
> 
> Signed-off-by: Ben Dooks <ben-linux@...ff.org>

I'm sorry, but I don't see how this is anywhere near acceptable. This
should be a panic at the very least, and until this can be sorted out
and avoided the driver should avoid using DMA on these chips.

-- 
     -- Pierre Ossman

  Linux kernel, MMC maintainer        http://www.kernel.org
  rdesktop, core developer          http://www.rdesktop.org

  WARNING: This correspondence is being monitored by the
  Swedish government. Make sure your server uses encryption
  for SMTP traffic and consider using PGP for end-to-end
  encryption.
--
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/