diff mbox series

[v2] wifi: nl80211: Split memcpy() of struct nl80211_wowlan_tcp_data_token flexible array

Message ID 20220927022923.1956205-1-keescook@chromium.org
State New
Headers show
Series [v2] wifi: nl80211: Split memcpy() of struct nl80211_wowlan_tcp_data_token flexible array | expand

Commit Message

Kees Cook Sept. 27, 2022, 2:29 a.m. UTC
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@chromium.org/

Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: linux-wireless@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
v2: - fix typo leading "+" (Gustavo)
v1: https://lore.kernel.org/lkml/20220927003903.1941873-1-keescook@chromium.org
---
 net/wireless/nl80211.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
diff mbox series

Patch

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;