lkml.org 
[lkml]   [2007]   [Feb]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 2.6.19.2] SCSI sd: udev accessing an uninitialized scsi_disk results in a crash
On Fri, Feb 02, 2007 at 05:19:24PM -0800, Andrew Morton wrote:
> On Fri, 2 Feb 2007 17:34:56 +0530
> Nagendra Singh Tomar <nagendra_tomar@adaptec.com> 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.

No objection from me, as long as James says this is ok.

I wonder why we haven't noticed this in the past?

thanks,

greg k-h
-
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/

\
 
 \ /
  Last update: 2007-02-03 03:17    [W:0.052 / U:0.816 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site