Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1946187AbXBCBTb (ORCPT ); Fri, 2 Feb 2007 20:19:31 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933409AbXBCBTa (ORCPT ); Fri, 2 Feb 2007 20:19:30 -0500 Received: from smtp.osdl.org ([65.172.181.24]:48177 "EHLO smtp.osdl.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933406AbXBCBT2 (ORCPT ); Fri, 2 Feb 2007 20:19:28 -0500 Date: Fri, 2 Feb 2007 17:19:24 -0800 From: Andrew Morton To: Nagendra Singh Tomar Cc: linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org, Greg KH , James Bottomley Subject: Re: [PATCH 2.6.19.2] SCSI sd: udev accessing an uninitialized scsi_disk results in a crash Message-Id: <20070202171924.a225cff7.akpm@linux-foundation.org> In-Reply-To: <200702021734.57161.nagendra_tomar@adaptec.com> References: <200702021734.57161.nagendra_tomar@adaptec.com> X-Mailer: Sylpheed version 2.2.7 (GTK+ 2.8.6; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2288 Lines: 60 On Fri, 2 Feb 2007 17:34:56 +0530 Nagendra Singh Tomar wrote: > Hi, > sd_probe() calls class_device_add() even before initializing the > sdkp->device variable. class_device_add() eventually results in the user mode > udev program to be called. udev program can read the the allow_restart > attribute of the newly created scsi device. This is resulting in a crash as > the show function for allow_restart (i.e sd_show_allow_restart) returns the > attribute value by reading the sdkp->device->allow_restart variable. As the > sdkp->device is not initialized before calling the user mode hotplug helper, > this results in a crash. > The patch below solves it by calling class_device_add() only after the > necessary fields in the scsi_disk structure are initialized properly. > > > > --- linux-2.6.19.2/drivers/scsi/sd.c.orig 2007-02-02 17:03:03.000000000 +0530 > +++ linux-2.6.19.2/drivers/scsi/sd.c 2007-02-02 17:04:04.000000000 +0530 > @@ -1646,16 +1646,6 @@ static int sd_probe(struct device *dev) > if (error) > goto out_put; > > - class_device_initialize(&sdkp->cdev); > - sdkp->cdev.dev = &sdp->sdev_gendev; > - sdkp->cdev.class = &sd_disk_class; > - strncpy(sdkp->cdev.class_id, sdp->sdev_gendev.bus_id, BUS_ID_SIZE); > - > - if (class_device_add(&sdkp->cdev)) > - goto out_put; > - > - get_device(&sdp->sdev_gendev); > - > sdkp->device = sdp; > sdkp->driver = &sd_template; > sdkp->disk = gd; > @@ -1669,6 +1659,16 @@ static int sd_probe(struct device *dev) > sdp->timeout = SD_MOD_TIMEOUT; > } > > + class_device_initialize(&sdkp->cdev); > + sdkp->cdev.dev = &sdp->sdev_gendev; > + sdkp->cdev.class = &sd_disk_class; > + strncpy(sdkp->cdev.class_id, sdp->sdev_gendev.bus_id, BUS_ID_SIZE); > + > + if (class_device_add(&sdkp->cdev)) > + goto out_put; > + > + get_device(&sdp->sdev_gendev); > + > gd->major = sd_major((index & 0xf0) >> 4); > gd->first_minor = ((index & 0xf) << 4) | (index & 0xfff00); > gd->minors = 16; Thanks - I'll queue this up for 2.6.20 also. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/