[SCSI] mpt2sas: Null pointer deference possibility in mpt2sas_ctl_event_callback function

Added a check to identify if mpi_reply is NULL in mpt2sas_ctl_event_callback()
and return without proceeding if it is the case.

Also modified the following functions to return void instead of 0 or 1
as returning those values from events perspective doesn't make sense.
* _base_async_event()
* mpt2sas_ctl_event_callback()
* mpt2sas_scsih_event_callback()

Signed-off-by: Sreekanth Reddy <Sreekanth.Reddy@lsi.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

1 files changed, 8 insertions, 4 deletions

diff --git a/drivers/scsi/mpt2sas/mpt2sas_ctl.c b/drivers/scsi/mpt2sas/mpt2sas_ctl.c
index eec052c2670..2878bd4cae3 100644
--- a/drivers/scsi/mpt2sas/mpt2sas_ctl.c
+++ b/drivers/scsi/mpt2sas/mpt2sas_ctl.c
@@ -397,18 +397,22 @@ mpt2sas_ctl_add_to_event_log(struct MPT2SAS_ADAPTER *ioc,
  * This function merely adds a new work task into ioc->firmware_event_thread.
  * The tasks are worked from _firmware_event_work in user context.
  *
- * Return 1 meaning mf should be freed from _base_interrupt
- *        0 means the mf is freed from this function.
+ * Returns void.
  */
-u8
+void
 mpt2sas_ctl_event_callback(struct MPT2SAS_ADAPTER *ioc, u8 msix_index,
 	u32 reply)
 {
 	Mpi2EventNotificationReply_t *mpi_reply;
 
 	mpi_reply = mpt2sas_base_get_reply_virt_addr(ioc, reply);
+	if (unlikely(!mpi_reply)) {
+		printk(MPT2SAS_ERR_FMT "mpi_reply not valid at %s:%d/%s()!\n",
+		    ioc->name, __FILE__, __LINE__, __func__);
+		return;
+	}
 	mpt2sas_ctl_add_to_event_log(ioc, mpi_reply);
-	return 1;
+	return;
 }
 
 /**