From: FUJITA Tomonori Date: Sat, 26 Jul 2008 14:25:43 +0000 (+0900) Subject: [SCSI] ch: fix ch_remove oops X-Git-Tag: v2.6.27-rc1~55^2~7 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3d164fb09bb5cb8a223eddf634fc0d355714fcfe;p=linux-2.6 [SCSI] ch: fix ch_remove oops The following commit causes ch_remove oops: commit 24b42566c3fcbb5a9011d1446783d0f5844ccd45 Author: Greg Kroah-Hartman 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 Cc: Doug Gilbert Cc: James E.J. Bottomley Signed-off-by: Greg Kroah-Hartman 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 Signed-off-by: James Bottomley --- diff --git a/drivers/scsi/ch.c b/drivers/scsi/ch.c index aa2011b646..3c257fe089 100644 --- a/drivers/scsi/ch.c +++ b/drivers/scsi/ch.c @@ -930,6 +930,7 @@ 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;