From 0c9e025e797e02c35449b3ad08d3317e5fc7d7b8 Mon Sep 17 00:00:00 2001
From: Mordechay Goodstein <mordechay.goodstein@intel.com>
Date: Fri, 24 Apr 2020 18:48:11 +0300
Subject: [PATCH] iwlwifi: yoyo: don't access TLV before verifying len
Git-commit: 0c9e025e797e02c35449b3ad08d3317e5fc7d7b8
Patch-mainline: v5.8-rc1
References: jsc#SLE-13430

If we access the TLV memory with shorter len than the struct
we access garbage data that was not given by the user.

On the way rewrite the checker in a cleaner way.

Signed-off-by: Mordechay Goodstein <mordechay.goodstein@intel.com>
Fixes: a9248de42464 ("iwlwifi: dbg_ini: add TLV allocation new API support")
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20200424182644.54418c829390.I15d6b462a0e69a280b6c6cfbcb6bcb05bb5f79ee@changeid
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 .../net/wireless/intel/iwlwifi/fw/api/dbg-tlv.h    |  5 ++-
 drivers/net/wireless/intel/iwlwifi/iwl-dbg-tlv.c   | 44 +++++++++++-----------
 2 files changed, 24 insertions(+), 25 deletions(-)

diff --git a/drivers/net/wireless/intel/iwlwifi/fw/api/dbg-tlv.h b/drivers/net/wireless/intel/iwlwifi/fw/api/dbg-tlv.h
index b9d7ed93311c..74ac65bd545a 100644
--- a/drivers/net/wireless/intel/iwlwifi/fw/api/dbg-tlv.h
+++ b/drivers/net/wireless/intel/iwlwifi/fw/api/dbg-tlv.h
@@ -5,7 +5,7 @@
  *
  * GPL LICENSE SUMMARY
  *
- * Copyright (C) 2018 - 2019 Intel Corporation
+ * Copyright (C) 2018 - 2020 Intel Corporation
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of version 2 of the GNU General Public License as
@@ -25,7 +25,7 @@
  *
  * BSD LICENSE
  *
- * Copyright (C) 2018 - 2019 Intel Corporation
+ * Copyright (C) 2018 - 2020 Intel Corporation
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -304,6 +304,7 @@ enum iwl_fw_ini_buffer_location {
 	IWL_FW_INI_LOCATION_SRAM_PATH,
 	IWL_FW_INI_LOCATION_DRAM_PATH,
 	IWL_FW_INI_LOCATION_NPK_PATH,
+	IWL_FW_INI_LOCATION_NUM,
 }; /* FW_DEBUG_TLV_BUFFER_LOCATION_E_VER_1 */
 
 /**
diff --git a/drivers/net/wireless/intel/iwlwifi/iwl-dbg-tlv.c b/drivers/net/wireless/intel/iwlwifi/iwl-dbg-tlv.c
index 9eb8fbfaa2a2..7987a288917b 100644
--- a/drivers/net/wireless/intel/iwlwifi/iwl-dbg-tlv.c
+++ b/drivers/net/wireless/intel/iwlwifi/iwl-dbg-tlv.c
@@ -165,38 +165,36 @@ static int iwl_dbg_tlv_alloc_buf_alloc(struct iwl_trans *trans,
 				       struct iwl_ucode_tlv *tlv)
 {
 	struct iwl_fw_ini_allocation_tlv *alloc = (void *)tlv->data;
-	u32 buf_location = le32_to_cpu(alloc->buf_location);
-	u32 alloc_id = le32_to_cpu(alloc->alloc_id);
+	u32 buf_location;
+	u32 alloc_id;
 
-	if (le32_to_cpu(tlv->length) != sizeof(*alloc) ||
-	    (buf_location != IWL_FW_INI_LOCATION_SRAM_PATH &&
-	     buf_location != IWL_FW_INI_LOCATION_DRAM_PATH &&
-	     buf_location != IWL_FW_INI_LOCATION_NPK_PATH)) {
-		IWL_ERR(trans,
-			"WRT: Invalid allocation TLV\n");
+	if (le32_to_cpu(tlv->length) != sizeof(*alloc))
 		return -EINVAL;
-	}
 
-	if ((buf_location == IWL_FW_INI_LOCATION_SRAM_PATH ||
-	     buf_location == IWL_FW_INI_LOCATION_NPK_PATH) &&
-	     alloc_id != IWL_FW_INI_ALLOCATION_ID_DBGC1) {
-		IWL_ERR(trans,
-			"WRT: Allocation TLV for SMEM/NPK path must have id %u (current: %u)\n",
-			IWL_FW_INI_ALLOCATION_ID_DBGC1, alloc_id);
-		return -EINVAL;
-	}
+	buf_location = le32_to_cpu(alloc->buf_location);
+	alloc_id = le32_to_cpu(alloc->alloc_id);
+
+	if (buf_location == IWL_FW_INI_LOCATION_INVALID ||
+	    buf_location >= IWL_FW_INI_LOCATION_NUM)
+		goto err;
 
 	if (alloc_id == IWL_FW_INI_ALLOCATION_INVALID ||
-	    alloc_id >= IWL_FW_INI_ALLOCATION_NUM) {
-		IWL_ERR(trans,
-			"WRT: Invalid allocation id %u for allocation TLV\n",
-			alloc_id);
-		return -EINVAL;
-	}
+	    alloc_id >= IWL_FW_INI_ALLOCATION_NUM)
+		goto err;
+
+	if ((buf_location == IWL_FW_INI_LOCATION_SRAM_PATH ||
+	     buf_location == IWL_FW_INI_LOCATION_NPK_PATH) &&
+	     alloc_id != IWL_FW_INI_ALLOCATION_ID_DBGC1)
+		goto err;
 
 	trans->dbg.fw_mon_cfg[alloc_id] = *alloc;
 
 	return 0;
+err:
+	IWL_ERR(trans,
+		"WRT: Invalid allocation id %u and/or location id %u for allocation TLV\n",
+		alloc_id, buf_location);
+	return -EINVAL;
 }
 
 static int iwl_dbg_tlv_alloc_hcmd(struct iwl_trans *trans,
-- 
2.16.4