scsi: mvsas: mv_sas.c: Fix for possible null pointer dereference

There is otherwise a risk of a possible null pointer dereference.

Was largely found by using a static code analysis program called cppcheck.

Signed-off-by: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

diff --git a/drivers/scsi/mvsas/mv_sas.c b/drivers/scsi/mvsas/mv_sas.c
index 6c1f223..ac52f7c 100644 (file)
--- a/drivers/scsi/mvsas/mv_sas.c
+++ b/drivers/scsi/mvsas/mv_sas.c
@@ -1344,19 +1344,23 @@ 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;
        mvi_dev->sas_device = NULL;