From: Kees Cook <keescook@chromium.org>
To: Johannes Berg <johannes@sipsolutions.net>
Cc: Kees Cook <keescook@chromium.org>,
"David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
linux-wireless@vger.kernel.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org
Subject: [PATCH] wifi: nl80211: Split memcpy() of struct nl80211_wowlan_tcp_data_token flexible array
Date: Mon, 26 Sep 2022 17:39:03 -0700 [thread overview]
Message-ID: <20220927003903.1941873-1-keescook@chromium.org> (raw)
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>
---
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
next reply other threads:[~2022-09-27 0:39 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-27 0:39 Kees Cook [this message]
2022-09-27 1:33 ` [PATCH] wifi: nl80211: Split memcpy() of struct nl80211_wowlan_tcp_data_token flexible array Gustavo A. R. Silva
2022-09-27 2:27 ` Kees Cook
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