[PATCH] wifi: nl80211: Split memcpy() of struct nl80211_wowlan_tcp_data_token flexible array

[Kees Cook]

To work around a misbehavior of the compiler's ability to see into
composite flexible array structs (as detailed in the coming memcpy()
hardening series[1]), split the memcpy() of the header and the payload
so no false positive run-time overflow warning will be generated.

[1] https://lore.kernel.org/linux-hardening/20220901065914.1417829-2-keescook@xxxxxxxxxxxx/

Cc: Johannes Berg <johannes@xxxxxxxxxxxxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: Eric Dumazet <edumazet@xxxxxxxxxx>
Cc: Jakub Kicinski <kuba@xxxxxxxxxx>
Cc: Paolo Abeni <pabeni@xxxxxxxxxx>
Cc: linux-wireless@xxxxxxxxxxxxxxx
Cc: netdev@xxxxxxxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
 net/wireless/nl80211.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 2705e3ee8fc4..461897933e92 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -13171,7 +13171,8 @@ static int nl80211_parse_wowlan_tcp(struct cfg80211_registered_device *rdev,
 	       wake_mask_size);
 	if (tok) {
 		cfg->tokens_size = tokens_size;
-		memcpy(&cfg->payload_tok, tok, sizeof(*tok) + tokens_size);
+		cfg->payload_tok = *tok;
+		memcpy(cfg->payload_tok.token_stream, tok->token_stream, + tokens_size);
 	}
 
 	trig->tcp = cfg;
-- 
2.34.1