wifi: iwlwifi: mvm: validate MCC header before n_channels

MCC response parsing read n_channels from v8/v4/v3 response variants
before ensuring the payload contained the fixed response header.

Add a minimum payload-length check for each response version before
reading n_channels, and keep the existing exact-size validation for the
channels array payload.

Assisted-by: GitHub Copilot:gpt-5.3-codex
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Link: https://patch.msgid.link/20260714141909.cb2cef3d3e7e.Iee7b48614289da576de842157ad3730b7589a4b1@changeid
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>

1 files changed, 36 insertions, 7 deletions

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/nvm.c b/drivers/net/wireless/intel/iwlwifi/mvm/nvm.c
index 953218f1e025..f76e57399c1f 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/nvm.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/nvm.c
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
 /*
- * Copyright (C) 2012-2014, 2018-2019, 2021-2025 Intel Corporation
+ * Copyright (C) 2012-2014, 2018-2019, 2021-2026 Intel Corporation
  * Copyright (C) 2013-2015 Intel Mobile Communications GmbH
  * Copyright (C) 2016-2017 Intel Deutschland GmbH
  */
@@ -416,6 +416,7 @@ iwl_mvm_update_mcc(struct iwl_mvm *mvm, const char *alpha2,
 	int ret, resp_ver;
 	u32 status;
 	int resp_len, n_channels;
+	unsigned int pkt_len;
 	u16 mcc;
 
 	if (WARN_ON_ONCE(!iwl_mvm_is_lar_supported(mvm)))
@@ -431,6 +432,7 @@ iwl_mvm_update_mcc(struct iwl_mvm *mvm, const char *alpha2,
 		return ERR_PTR(ret);
 
 	pkt = cmd.resp_pkt;
+	pkt_len = iwl_rx_packet_payload_len(pkt);
 
 	resp_ver = iwl_fw_lookup_notif_ver(mvm->fw, IWL_ALWAYS_LONG_GROUP,
 					   MCC_UPDATE_CMD, 0);
@@ -439,9 +441,18 @@ iwl_mvm_update_mcc(struct iwl_mvm *mvm, const char *alpha2,
 	if (resp_ver >= 8) {
 		struct iwl_mcc_update_resp_v8 *mcc_resp_v8 = (void *)pkt->data;
 
+		if (IWL_FW_CHECK(mvm, pkt_len < sizeof(*mcc_resp_v8),
+				 "MCC v8 response too short: %u\n", pkt_len)) {
+			resp_cp = ERR_PTR(-EINVAL);
+			goto exit;
+		}
+
 		n_channels =  __le32_to_cpu(mcc_resp_v8->n_channels);
-		if (iwl_rx_packet_payload_len(pkt) !=
-		    struct_size(mcc_resp_v8, channels, n_channels)) {
+		if (IWL_FW_CHECK(mvm,
+				 pkt_len !=
+				 struct_size(mcc_resp_v8, channels, n_channels),
+				 "invalid MCC v8 response size: %u (n_channels=%d)\n",
+				 pkt_len, n_channels)) {
 			resp_cp = ERR_PTR(-EINVAL);
 			goto exit;
 		}
@@ -464,9 +475,18 @@ iwl_mvm_update_mcc(struct iwl_mvm *mvm, const char *alpha2,
 			       IWL_UCODE_TLV_CAPA_MCC_UPDATE_11AX_SUPPORT)) {
 		struct iwl_mcc_update_resp_v4 *mcc_resp_v4 = (void *)pkt->data;
 
+		if (IWL_FW_CHECK(mvm, pkt_len < sizeof(*mcc_resp_v4),
+				 "MCC v4 response too short: %u\n", pkt_len)) {
+			resp_cp = ERR_PTR(-EINVAL);
+			goto exit;
+		}
+
 		n_channels =  __le32_to_cpu(mcc_resp_v4->n_channels);
-		if (iwl_rx_packet_payload_len(pkt) !=
-		    struct_size(mcc_resp_v4, channels, n_channels)) {
+		if (IWL_FW_CHECK(mvm,
+				 pkt_len !=
+				 struct_size(mcc_resp_v4, channels, n_channels),
+				 "invalid MCC v4 response size: %u (n_channels=%d)\n",
+				 pkt_len, n_channels)) {
 			resp_cp = ERR_PTR(-EINVAL);
 			goto exit;
 		}
@@ -489,9 +509,18 @@ iwl_mvm_update_mcc(struct iwl_mvm *mvm, const char *alpha2,
 	} else {
 		struct iwl_mcc_update_resp_v3 *mcc_resp_v3 = (void *)pkt->data;
 
+		if (IWL_FW_CHECK(mvm, pkt_len < sizeof(*mcc_resp_v3),
+				 "MCC v3 response too short: %u\n", pkt_len)) {
+			resp_cp = ERR_PTR(-EINVAL);
+			goto exit;
+		}
+
 		n_channels =  __le32_to_cpu(mcc_resp_v3->n_channels);
-		if (iwl_rx_packet_payload_len(pkt) !=
-		    struct_size(mcc_resp_v3, channels, n_channels)) {
+		if (IWL_FW_CHECK(mvm,
+				 pkt_len !=
+				 struct_size(mcc_resp_v3, channels, n_channels),
+				 "invalid MCC v3 response size: %u (n_channels=%d)\n",
+				 pkt_len, n_channels)) {
 			resp_cp = ERR_PTR(-EINVAL);
 			goto exit;
 		}