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 F395118B491; Tue, 30 Jul 2024 16:16:50 +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=1722356211; cv=none; b=pVWY+GlM3FbBL08zrN+rUa1qYN2cqhGI+xXyPwYq7oARTlvQWAxpAS55u9lRIV/EvS+8SV3v/e+JGZ8COeB67CUZd8ZHSFKkoaFlT/xKQ7Ax+wilyvaVr7C3NmGXpSeUGdLyV913wn0boB4p1syQLt9Sv2jELcB4TrTVvqoypn4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722356211; c=relaxed/simple; bh=TungPDSBvGniqiButLJu7ZDGJ4Ogm7kx66Pz1xX8ZtA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=BWayfVxyFNYwxnhIfmI+UdRa+r6rwIK71zEvYjs5pxvRf3xa8P+wYwWBdhKAADKWOGnNRfZ3qXg+YmUIw4HiCm30rBMverX3LijErm8EOeU9bzz+7ZV0nAocFQmae3n+1Pxkk4Rujid4gAvrykmJGk9llmOHaMDBXvT4wSh3tag= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=diW/20tg; 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="diW/20tg" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2288FC32782; Tue, 30 Jul 2024 16:16:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1722356210; bh=TungPDSBvGniqiButLJu7ZDGJ4Ogm7kx66Pz1xX8ZtA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=diW/20tgi3DNtzi0CsBML99QKH4zB/Krmp/3qg0+vNeoUSGcHtma1mew96no5U9Hf PO8B9y0xuv6diDghJk1AXlqcPaDn2u1c82+pEYQ8oBG+CRvzaJdXXvvq/+pqwgDOea 9F5WrzXizi4fmMmuef5llenSDxAdb6+hnWutia9c= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Eric Dumazet , Neal Cardwell , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.6 124/568] tcp: fix races in tcp_v[46]_err() Date: Tue, 30 Jul 2024 17:43:51 +0200 Message-ID: <20240730151644.720954362@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240730151639.792277039@linuxfoundation.org> References: <20240730151639.792277039@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev 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 fde6f897f2a184546bf5516ac736523ef24dc6a7 ] These functions have races when they: 1) Write sk->sk_err 2) call sk_error_report(sk) 3) call tcp_done(sk) As described in prior patches in this series: An smp_wmb() is missing. We should call tcp_done() before sk_error_report(sk) to have consistent tcp_poll() results on SMP hosts. Use tcp_done_with_error() where we centralized the correct sequence. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet Acked-by: Neal Cardwell Link: https://lore.kernel.org/r/20240528125253.1966136-5-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/ipv4/tcp_ipv4.c | 11 +++-------- net/ipv6/tcp_ipv6.c | 10 +++------- 2 files changed, 6 insertions(+), 15 deletions(-) diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 7c2ca4df0daa3..48ec2c1777d45 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -602,15 +602,10 @@ int tcp_v4_err(struct sk_buff *skb, u32 info) ip_icmp_error(sk, skb, err, th->dest, info, (u8 *)th); - if (!sock_owned_by_user(sk)) { - WRITE_ONCE(sk->sk_err, err); - - sk_error_report(sk); - - tcp_done(sk); - } else { + if (!sock_owned_by_user(sk)) + tcp_done_with_error(sk, err); + else WRITE_ONCE(sk->sk_err_soft, err); - } goto out; } diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 07bcb690932e1..d0034916d386b 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -488,14 +488,10 @@ static int tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, ipv6_icmp_error(sk, skb, err, th->dest, ntohl(info), (u8 *)th); - if (!sock_owned_by_user(sk)) { - WRITE_ONCE(sk->sk_err, err); - sk_error_report(sk); /* Wake people up to see the error (see connect in sock.c) */ - - tcp_done(sk); - } else { + if (!sock_owned_by_user(sk)) + tcp_done_with_error(sk, err); + else WRITE_ONCE(sk->sk_err_soft, err); - } goto out; case TCP_LISTEN: break; -- 2.43.0