From cb0a1fb7fd86b0062692b5056ca8552906509512 Mon Sep 17 00:00:00 2001
From: Kees Cook <keescook@chromium.org>
Date: Tue, 27 Jul 2021 13:58:54 -0700
Subject: [PATCH] iwlwifi: dbg_ini: Split memcpy() to avoid multi-field write
Git-commit: cb0a1fb7fd86b0062692b5056ca8552906509512
Patch-mainline: v5.18-rc1
References: bsc#1202131

To avoid a run-time false positive in the stricter FORTIFY_SOURCE
memcpy() checks, split the memcpy() into the struct and the data.
Additionally switch the data member to a flexible array to follow
modern language conventions.

Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210727205855.411487-64-keescook@chromium.org
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/net/wireless/intel/iwlwifi/fw/file.h     | 2 +-
 drivers/net/wireless/intel/iwlwifi/iwl-dbg-tlv.c | 3 ++-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/intel/iwlwifi/fw/file.h b/drivers/net/wireless/intel/iwlwifi/fw/file.h
index f44aedb3f049..fa2a73ae4183 100644
--- a/drivers/net/wireless/intel/iwlwifi/fw/file.h
+++ b/drivers/net/wireless/intel/iwlwifi/fw/file.h
@@ -119,7 +119,7 @@ enum iwl_ucode_tlv_type {
 struct iwl_ucode_tlv {
 	__le32 type;		/* see above */
 	__le32 length;		/* not including type/length fields */
-	u8 data[0];
+	u8 data[];
 };
 
 #define IWL_TLV_UCODE_MAGIC		0x0a4c5749
diff --git a/drivers/net/wireless/intel/iwlwifi/iwl-dbg-tlv.c b/drivers/net/wireless/intel/iwlwifi/iwl-dbg-tlv.c
index bf167bdd02cd..866a33f49915 100644
--- a/drivers/net/wireless/intel/iwlwifi/iwl-dbg-tlv.c
+++ b/drivers/net/wireless/intel/iwlwifi/iwl-dbg-tlv.c
@@ -74,7 +74,8 @@ static int iwl_dbg_tlv_add(const struct iwl_ucode_tlv *tlv,
 	if (!node)
 		return -ENOMEM;
 
-	memcpy(&node->tlv, tlv, sizeof(node->tlv) + len);
+	memcpy(&node->tlv, tlv, sizeof(node->tlv));
+	memcpy(node->tlv.data, tlv->data, len);
 	list_add_tail(&node->list, list);
 
 	return 0;
-- 
2.35.3