Messages in this thread Patch in this message | | | Date | Mon, 4 Aug 2008 14:30:20 -0700 | From | Greg KH <> | Subject | [patch 11/25] SCSI: ch: fix ch_remove oops |
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2.6.26-stable review patch. If anyone has any objections, please let us know.
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From: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
commit 3d164fb09bb5cb8a223eddf634fc0d355714fcfe upstream.
The following commit causes ch_remove oops:
commit 24b42566c3fcbb5a9011d1446783d0f5844ccd45 Author: Greg Kroah-Hartman <gregkh@suse.de> Date: Fri May 16 17:55:12 2008 -0700
SCSI: fix race in device_create
There is a race from when a device is created with device_create() and then the drvdata is set with a call to dev_set_drvdata() in which a sysfs file could be open, yet the drvdata will be NULL, causing all sorts of bad things to happen.
This patch fixes the problem by using the new function, device_create_drvdata(). It fixes the problem in all of the scsi drivers that need it.
Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: Doug Gilbert <dgilbert@interlog.com> Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The problem is ch_probe stores ch's private data at a wrong place.
We need to store it at scsi_device->sdev_gendev but the above patch stores it at device struct that device_create_drvdata returns. So we hit an oops when ch_remove accesses scsi_device->sdev_gendev->driver_data, which is NULL.
Actually, there wasn't a race because ch doesn't create sysfs files with device struct that device_create returns. This patch puts back dev_set_drvdata() to set ch's private data properly.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- drivers/scsi/ch.c | 1 + 1 file changed, 1 insertion(+)
--- a/drivers/scsi/ch.c +++ b/drivers/scsi/ch.c @@ -926,6 +926,7 @@ static int ch_probe(struct device *dev) if (init) ch_init_elem(ch); + dev_set_drvdata(dev, ch); sdev_printk(KERN_INFO, sd, "Attached scsi changer %s\n", ch->name); return 0; --
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