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> --- v2: - fix typo leading "+" (Gustavo) v1: https://lore.kernel.org/lkml/20220927003903.1941873-1-keescook@xxxxxxxxxxxx --- net/wireless/nl80211.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index 2705e3ee8fc4..169e3ec33466 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -13171,7 +13171,9 @@ 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
