[SCSI] mpt2sas: Fix security scan issues reported by source code analysis tool

Modified the source code as per the findings reported by the source
code analysis tool. Source code for the following functionalities
has been touched. None of the driver functionalities has changed.

- SMP Passthrough IOCTL
- Debug messages for MPT Replies (i.e. bit 9 of Logging Level)
- Task Management using sysfs
- Device removal, i.e. when a target device (including any PD within a volume)
  is removed, and Volume Deletion.
- Trace Buffer

Signed-off-by: Nagalakshmi Nandigama <nagalakshmi.nandigama@lsi.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

drivers/scsi/mpt2sas/mpt2sas_base.c

@@ -699,6 +699,11 @@ _base_display_reply_info(struct MPT2SAS_ADAPTER *ioc, u16 smid, u8 msix_index,
 	u16 ioc_status;
 
 	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;
+	}
 	ioc_status = le16_to_cpu(mpi_reply->IOCStatus);
 #ifdef CONFIG_SCSI_MPT2SAS_LOGGING
 	if ((ioc_status & MPI2_IOCSTATUS_MASK) &&
@@ -930,16 +935,18 @@ _base_interrupt(int irq, void *bus_id)
 		else if (request_desript_type ==
 		    MPI2_RPY_DESCRIPT_FLAGS_TARGETASSIST_SUCCESS)
 			goto next;
-		if (smid)
+		if (smid) {
 			cb_idx = _base_get_cb_idx(ioc, smid);
-		if (smid && cb_idx != 0xFF) {
-			rc = mpt_callbacks[cb_idx](ioc, smid, msix_index,
-			    reply);
+		if ((likely(cb_idx < MPT_MAX_CALLBACKS))
+			    && (likely(mpt_callbacks[cb_idx] != NULL))) {
+				rc = mpt_callbacks[cb_idx](ioc, smid,
+				    msix_index, reply);
 			if (reply)
-				_base_display_reply_info(ioc, smid, msix_index,
-				    reply);
+				_base_display_reply_info(ioc, smid,
+				    msix_index, reply);
 			if (rc)
 				mpt2sas_base_free_smid(ioc, smid);
+			}
 		}
 		if (!smid)
 			_base_async_event(ioc, msix_index, reply);

drivers/scsi/mpt2sas/mpt2sas_ctl.c

@@ -865,8 +865,16 @@ _ctl_do_mpt_command(struct MPT2SAS_ADAPTER *ioc, struct mpt2_ioctl_command karg,
 		if (smp_request->PassthroughFlags &
 		    MPI2_SMP_PT_REQ_PT_FLAGS_IMMEDIATE)
 			data = (u8 *)&smp_request->SGL;
-		else
+		else {
+			if (unlikely(data_out == NULL)) {
+				printk(KERN_ERR "failure at %s:%d/%s()!\n",
+				    __FILE__, __LINE__, __func__);
+				mpt2sas_base_free_smid(ioc, smid);
+				ret = -EINVAL;
+				goto out;
+			}
 			data = data_out;
+		}
 
 		if (data[1] == 0x91 && (data[10] == 1 || data[10] == 2)) {
 			ioc->ioc_link_reset_in_progress = 1;
@@ -2832,7 +2840,7 @@ _ctl_host_trace_buffer_enable_store(struct device *cdev,
 	struct mpt2_diag_register diag_register;
 	u8 issue_reset = 0;
 
-	if (sscanf(buf, "%s", str) != 1)
+	if (sscanf(buf, "%9s", str) != 1)
 		return -EINVAL;
 
 	if (!strcmp(str, "post")) {

drivers/scsi/mpt2sas/mpt2sas_scsih.c

@@ -3186,16 +3186,19 @@ static u8
 _scsih_sas_control_complete(struct MPT2SAS_ADAPTER *ioc, u16 smid,
     u8 msix_index, u32 reply)
 {
-#ifdef CONFIG_SCSI_MPT2SAS_LOGGING
 	Mpi2SasIoUnitControlReply_t *mpi_reply =
 	    mpt2sas_base_get_reply_virt_addr(ioc, reply);
-#endif
-	dewtprintk(ioc, printk(MPT2SAS_INFO_FMT
-	    "sc_complete:handle(0x%04x), (open) "
-	    "smid(%d), ioc_status(0x%04x), loginfo(0x%08x)\n",
-	    ioc->name, le16_to_cpu(mpi_reply->DevHandle), smid,
-	    le16_to_cpu(mpi_reply->IOCStatus),
-	    le32_to_cpu(mpi_reply->IOCLogInfo)));
+	if (likely(mpi_reply)) {
+		dewtprintk(ioc, printk(MPT2SAS_INFO_FMT
+		"sc_complete:handle(0x%04x), (open) "
+		"smid(%d), ioc_status(0x%04x), loginfo(0x%08x)\n",
+		ioc->name, le16_to_cpu(mpi_reply->DevHandle), smid,
+		le16_to_cpu(mpi_reply->IOCStatus),
+		le32_to_cpu(mpi_reply->IOCLogInfo)));
+	} else {
+		printk(MPT2SAS_ERR_FMT "mpi_reply not valid at %s:%d/%s()!\n",
+		    ioc->name, __FILE__, __LINE__, __func__);
+	}
 	return 1;
 }
 
@@ -3274,7 +3277,11 @@ _scsih_tm_volume_tr_complete(struct MPT2SAS_ADAPTER *ioc, u16 smid,
 		   "progress!\n", __func__, ioc->name));
 		return 1;
 	}
-
+	if (unlikely(!mpi_reply)) {
+		printk(MPT2SAS_ERR_FMT "mpi_reply not valid at %s:%d/%s()!\n",
+		    ioc->name, __FILE__, __LINE__, __func__);
+		return 1;
+	}
 	mpi_request_tm = mpt2sas_base_get_msg_frame(ioc, smid);
 	handle = le16_to_cpu(mpi_request_tm->DevHandle);
 	if (handle != le16_to_cpu(mpi_reply->DevHandle)) {
@@ -3337,7 +3344,11 @@ _scsih_tm_tr_complete(struct MPT2SAS_ADAPTER *ioc, u16 smid, u8 msix_index,
 		    "operational\n", __func__, ioc->name));
 		return 1;
 	}
-
+	if (unlikely(!mpi_reply)) {
+		printk(MPT2SAS_ERR_FMT "mpi_reply not valid at %s:%d/%s()!\n",
+		    ioc->name, __FILE__, __LINE__, __func__);
+		return 1;
+	}
 	mpi_request_tm = mpt2sas_base_get_msg_frame(ioc, smid);
 	handle = le16_to_cpu(mpi_request_tm->DevHandle);
 	if (handle != le16_to_cpu(mpi_reply->DevHandle)) {
@@ -7353,6 +7364,13 @@ mpt2sas_scsih_event_callback(struct MPT2SAS_ADAPTER *ioc, u8 msix_index,
 		return 1;
 
 	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 1;
+	}
+
 	event = le16_to_cpu(mpi_reply->Event);
 
 	switch (event) {