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 0E0B018131D; Wed, 3 Jul 2024 10:43:31 +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=1720003412; cv=none; b=dj3qBhihBUGstz7vSEiXlGawFMXOKcRW9m5Yu2XCkwLDSe+Rj6HZgY8Xzrv85uyfigPdrye+vOfmz9lldhH9h1F+91gxtoYP8FVrNgTOr0+qAAbGedytEqs77KwvNqd3eei/U2QyP40qI9rfjFSkysY/8zIJtc2/3aMUYgywHfk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720003412; c=relaxed/simple; bh=runSFBJaOtucObIqHsKrLE3xEPIwdv9ZPrOraF7ycmI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=q/LhbGelU1CLeZb2SmFLM+sJqVQKVP+OsoJYS+JyZyXOJ6e3AMOiwOF++HGADNwrnvvNuXu1I6/ppuNvk3hV5o80+3+hLuKoxKi7aTRbeA5hvRuRbjLQezrHKVno1B+QDQAntJGod3EVPqYgmG+1KNnA64DHEXGQdH2fbjfHN1U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=i3wEOAPK; 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="i3wEOAPK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 52EC9C2BD10; Wed, 3 Jul 2024 10:43:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1720003411; bh=runSFBJaOtucObIqHsKrLE3xEPIwdv9ZPrOraF7ycmI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=i3wEOAPKrLIowrEg1gPIpNYYCCoK2Xsf03PH6ia8zVZaALmDcKIuACRliU6BpmGxC sdQVSdsx8FtLMjLIVix6Y+mXqVSCM7mxr+ro2AID6cA+ODnKP1WBO9QS+Tx+n4YOHr kJuOgBxoPN+HNtUdf7LcEewit5uRIOA+hLBW8Bh0= 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 4.19 040/139] tcp: fix race in tcp_v6_syn_recv_sock() Date: Wed, 3 Jul 2024 12:38:57 +0200 Message-ID: <20240703102831.952764869@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240703102830.432293640@linuxfoundation.org> References: <20240703102830.432293640@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 4.19-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 033cf81f34837..fca1b95d86a97 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -1177,7 +1177,6 @@ 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); newtcp6sk = (struct tcp6_sock *)newsk; @@ -1189,6 +1188,8 @@ 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