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 DBC7217332B; Wed, 3 Jul 2024 10:53:22 +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=1720004002; cv=none; b=MOQyJbHe0U8EFrohFlImlH5rtRVLvrjwWlFDDjzSrYVdkJbCCDrGcQbn0c1h9G5a6TkOM50g3c/nAxusMG3VBJ8k9vSt04DzbD2Ap+DKFdeKgJXSNtDuBVSA+HeMkr5jGOYMGviyc/P/3Sa9PXWflD2Iibrc0G6Gy3T69taSRz4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720004002; c=relaxed/simple; bh=JSEEKu5P3s4/TS8AsffBd/wO0ilaPeVFM4ehX7zCxW0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=HoxZ5dzbY9hPBe+DZmun77iWamgvMbN2OaDK4wmolPqzqQaHfmENVvUHM0NX/rq29ZB/KPTckIBAUeAMn2B3a63eMSETEtGlR/XgEjgI6wuVRdYB31KnAiTNn2xr0tAjRG/A4b9I7o+D2aRhDxta1K1+ZT4FKNumuuKERU6ypfg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=CWZvaWpS; 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="CWZvaWpS" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 609AFC32781; Wed, 3 Jul 2024 10:53:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1720004002; bh=JSEEKu5P3s4/TS8AsffBd/wO0ilaPeVFM4ehX7zCxW0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CWZvaWpS9ZVJ1SKtqvP77owj5Z1ro2QVI0RIK4h2SS7FsRCVRf7OPguC0mSmbyX4t dLmt1bKBpT7eOMwO1dm46mpbayFP7jlFEEActnih9GoQjgV1zpwJPzb3U0LJ4e+xN1 y2ytFe1VB7gQaNPYynyjVtDhyU0ThpS5aVuGfQg4= 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 5.4 060/189] tcp: fix race in tcp_v6_syn_recv_sock() Date: Wed, 3 Jul 2024 12:38:41 +0200 Message-ID: <20240703102843.774183220@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240703102841.492044697@linuxfoundation.org> References: <20240703102841.492044697@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 5.4-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 7cb622d300aa2..c5efbfe2a2c4a 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -1228,7 +1228,6 @@ 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); @@ -1239,6 +1238,8 @@ 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