[SCSI] sd: udev accessing an uninitialized scsi_disk field results in a crash
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.
Signed-off-by: Nagendra Singh Tomar <nagendra_tomar@adaptec.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 978bfc1..b781a90 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -1647,16 +1647,6 @@
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;
@@ -1670,6 +1660,16 @@
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;