On Mon, Sep 26, 2022 at 07:29:23PM -0700, Kees Cook wrote: > 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> Reviewed-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx> Thanks! -- Gustavo > --- > 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 >
