[patch 2/2] mvsas: dereferencing before checking
From: Dan Carpenter
Date: Wed Aug 11 2010 - 03:43:17 EST
If "mvi_dev" is NULL then we have to test it at the start of the function
and return if it is null. In the original code, we dereferenced "mvi_dev"
before the check to assign "mvi" and then we dereferenced "mvi" to take
the spin lock.
Signed-off-by: Dan Carpenter <error27@xxxxxxxxx>
diff --git a/drivers/scsi/mvsas/mv_sas.c b/drivers/scsi/mvsas/mv_sas.c
index 406246c..a5c5aa5 100644
--- a/drivers/scsi/mvsas/mv_sas.c
+++ b/drivers/scsi/mvsas/mv_sas.c
@@ -1379,19 +1379,21 @@ void mvs_dev_gone_notify(struct domain_device *dev)
{
unsigned long flags = 0;
struct mvs_device *mvi_dev = dev->lldd_dev;
- struct mvs_info *mvi = mvi_dev->mvi_info;
-
- spin_lock_irqsave(&mvi->lock, flags);
+ struct mvs_info *mvi;
- if (mvi_dev) {
- mv_dprintk("found dev[%d:%x] is gone.\n",
- mvi_dev->device_id, mvi_dev->dev_type);
- mvs_release_task(mvi, dev);
- mvs_free_reg_set(mvi, mvi_dev);
- mvs_free_dev(mvi_dev);
- } else {
+ if (!mvi_dev) {
mv_dprintk("found dev has gone.\n");
+ return;
}
+
+ mvi = mvi_dev->mvi_info;
+ spin_lock_irqsave(&mvi->lock, flags);
+
+ mv_dprintk("found dev[%d:%x] is gone.\n",
+ mvi_dev->device_id, mvi_dev->dev_type);
+ mvs_release_task(mvi, dev);
+ mvs_free_reg_set(mvi, mvi_dev);
+ mvs_free_dev(mvi_dev);
dev->lldd_dev = NULL;
spin_unlock_irqrestore(&mvi->lock, flags);
--
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