From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 84F6A82871; Wed, 19 Jun 2024 13:05:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718802302; cv=none; b=Kz0AT3Wbbc3HzwKfnb3oykP9RyLRCVprMl44ghdEIR0oPmNqkHKQzqpGzgQ5tBf9lxCxmtT5iNlLjHC0cXdi9g26OFz+yXdob0EeNRcvYISAOmIHwcgoVzjQu6FnNXD1Texd34QrcaKqdMTVxNKjLGz8Duy9xdkv3/PASaLME7g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718802302; c=relaxed/simple; bh=dyj/YXVluqWPinKDZ8NR+JqkTzYxzCw++33EhVI6XZ8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=tDwYTWwn4ATFfhE66QCY0ceg41r2Npvcy5cCsqOEt08YEDipDnOvixmD7aLhqsHRvGbI0N6WKm2jw++B7U2mQyoWvL02zaD2MVTXGkFIUmf9O3eX0Nb1rrB+IrN7pC0c82dR5j9+tikDfst3GMexeB/LQPpdx+SksDwj6LGiYmg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=p1WaYJQY; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="p1WaYJQY" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0A104C2BBFC; Wed, 19 Jun 2024 13:05:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1718802302; bh=dyj/YXVluqWPinKDZ8NR+JqkTzYxzCw++33EhVI6XZ8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=p1WaYJQYcidHwpuwHut+ywzSVDOl7/T012T/0ZEsPFkLXPlF+07TQZOxmJZV4pvSX v31uvqghziFYWl7oVcSfIlguT432k209VyCR1839oHdAPxVGJ1lRbevarctT1N6g2J LUaJw6OFntqsookEUEAeCGJ5gA1D9sQL6DpT2g5g= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Eric Dumazet , Simon Horman , "David S. Miller" , Sasha Levin Subject: [PATCH 6.6 149/267] tcp: fix race in tcp_v6_syn_recv_sock() Date: Wed, 19 Jun 2024 14:55:00 +0200 Message-ID: <20240619125612.065882601@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240619125606.345939659@linuxfoundation.org> References: <20240619125606.345939659@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit d37fe4255abe8e7b419b90c5847e8ec2b8debb08 ] tcp_v6_syn_recv_sock() calls ip6_dst_store() before inet_sk(newsk)->pinet6 has been set up. This means ip6_dst_store() writes over the parent (listener) np->dst_cookie. This is racy because multiple threads could share the same parent and their final np->dst_cookie could be wrong. Move ip6_dst_store() call after inet_sk(newsk)->pinet6 has been changed and after the copy of parent ipv6_pinfo. Fixes: e994b2f0fb92 ("tcp: do not lock listener to process SYN packets") Signed-off-by: Eric Dumazet Reviewed-by: Simon Horman Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/ipv6/tcp_ipv6.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 3783334ef2332..07bcb690932e1 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -1287,7 +1287,6 @@ static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff * */ newsk->sk_gso_type = SKB_GSO_TCPV6; - ip6_dst_store(newsk, dst, NULL, NULL); inet6_sk_rx_dst_set(newsk, skb); inet_sk(newsk)->pinet6 = tcp_inet6_sk(newsk); @@ -1298,6 +1297,8 @@ static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff * memcpy(newnp, np, sizeof(struct ipv6_pinfo)); + ip6_dst_store(newsk, dst, NULL, NULL); + newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr; newnp->saddr = ireq->ir_v6_loc_addr; newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr; -- 2.43.0