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 43B8113E037; Wed, 19 Jun 2024 13:31:45 +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=1718803905; cv=none; b=twtbSdMHGq3TEFPK9fk1h+WSeiCzhP+HacHJiMawCdI0J9NQ5aFd8JMwW5m4zejpHMwsmSTDSWWnYm6ddrPwRilKeI6A70Lc3FaDRdmtm9861rIgz+a/h4tR5RCMcI4nBdVU+aroUmkblmospHD19UMG1AaPBjoMRRTA1kyGnhM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718803905; c=relaxed/simple; bh=TCMBcqHCvT8L+HGaxImCuEy47dX4w0wiT5ycJxrhRWU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Md1wcn8UJsyyzdcLLwU4/TZQQxOGP/Ohe89mWxO8DYAgrVhkKUjfqUV+5pHn0u2y3wUzoppvkAKiY3BTEdIFGW8KsXIknHxYrsS/c8Bp0FxQs4aQS7wIO3YwZcCckgN8o8w8wBzJDbzHgvCKT2oZ1dOOt6siqH4M0lusVpYr2Uw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=YPftiq0H; 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="YPftiq0H" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BC772C2BBFC; Wed, 19 Jun 2024 13:31:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1718803905; bh=TCMBcqHCvT8L+HGaxImCuEy47dX4w0wiT5ycJxrhRWU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YPftiq0H1e61rJfmx06bUg0lDm2abNGrLB4BLUvhjy/xqxBE2Np5PwqquivHwSTWo e6EuBXFkLHaUfC0DlGd2Y7pERUeGQZSNZTMKRDFe/Wwrhw8cXjyWn80ey2mc/C6Y1q 4TPQgGd3rmoo0Pt9h3Za3NXTYGeWZTrqsTzwWBHU= 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 6.1 144/217] tcp: fix race in tcp_v6_syn_recv_sock() Date: Wed, 19 Jun 2024 14:56:27 +0200 Message-ID: <20240619125602.248174468@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240619125556.491243678@linuxfoundation.org> References: <20240619125556.491243678@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 6.1-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 ba9a22db5805c..4b0e05349862d 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -1291,7 +1291,6 @@ 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); @@ -1302,6 +1301,8 @@ 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