From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marek Vasut Subject: Re: [PATCH] pxa2xx_spi: fix memory corruption Date: Sun, 10 Jul 2011 01:05:48 +0200 Message-ID: <201107100105.48168.marek.vasut@gmail.com> References: <1310246098-21208-1-git-send-email-anarsoul@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Vasily Khoruzhick , spi-devel-general@lists.sourceforge.net, Eric Miao To: linux-arm-kernel@lists.infradead.org Return-path: In-Reply-To: <1310246098-21208-1-git-send-email-anarsoul@gmail.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org List-Id: linux-spi.vger.kernel.org On Saturday, July 09, 2011 11:14:58 PM Vasily Khoruzhick wrote: > pxa2xx_spi_probe allocates struct driver_data and null_dma_buf > at same time via spi_alloc_master(), but then calculates > null_dma_buf pointer incorrectly, and it causes memory corruption > later if DMA usage is enabled. > > Signed-off-by: Vasily Khoruzhick > --- > drivers/spi/pxa2xx_spi.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/drivers/spi/pxa2xx_spi.c b/drivers/spi/pxa2xx_spi.c > index dc25bee..ef38fbf 100644 > --- a/drivers/spi/pxa2xx_spi.c > +++ b/drivers/spi/pxa2xx_spi.c > @@ -1569,7 +1569,7 @@ static int __devinit pxa2xx_spi_probe(struct > platform_device *pdev) master->transfer = transfer; > > drv_data->ssp_type = ssp->type; > - drv_data->null_dma_buf = (u32 *)ALIGN((u32)(drv_data + > + drv_data->null_dma_buf = (u32 *)ALIGN(((u32)drv_data + > sizeof(struct driver_data)), 8); This thing looks a bit disturbing in itself. Like, where the heck is that thing pointing in the end ? Since some data are written to address in "null_dma_buf" ... isn't this just changing the corruption impact ? > > drv_data->ioaddr = ssp->mmio_base;