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 10A9130AAAD; Mon, 13 Oct 2025 15:01:19 +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=1760367679; cv=none; b=h8O+QgIAS805qkCo9I4QuyaRvLtcJTYRgCtRji9G7XOZJObmdLH4jBWNrAp+MQ9nJsywZ9R6FFYAm74DrYs48kQ42GCAkQMSfv9VKvYjzFlx5xrMLi55OJtpDD7GOECKM8tLzL784HrFy6ki6+JxHB8plgy0Kl+yU42+yyrZs1Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760367679; c=relaxed/simple; bh=iz8NZymndqihdgdSpyEjGm0M9xjhbSPGB0M8DinSmxw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=NEuhmWSJqx5sW5pfIU3Ijs1/8g+sBkio4rb75QS3ZMivc1USSDID9fr4pXk5Q9F0pta+toCdzNTtuyupbrBCtAMO7+jVCKcuY57Zbacw9kcixcYfHcEuyieYHQ6md78b0OITdidphHuNk/oHcKmB8xbIWAon1227TgR6H80xVMU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=hhe78Orv; 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="hhe78Orv" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 85942C4CEE7; Mon, 13 Oct 2025 15:01:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1760367678; bh=iz8NZymndqihdgdSpyEjGm0M9xjhbSPGB0M8DinSmxw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hhe78Orvvbv0aGl+p0LAnQ4sY4HOVTmGMOBWZLpSN9gTYU6FIDXRK9J+rL1DU2f95 hVdMIRc88rjdYIGOnywbdsmpnsLdJoNy5ol71W/cme/F2aqTze6utPtQ5uTWPA6keq b8fQfVhe0WR5NEAv2aDjs3G4M2BmcMvgdsl1QW64= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Eric Dumazet , Neal Cardwell , Kuniyuki Iwashima , Jason Xing , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.6 094/196] tcp: fix __tcp_close() to only send RST when required Date: Mon, 13 Oct 2025 16:44:45 +0200 Message-ID: <20251013144318.718184722@linuxfoundation.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251013144315.184275491@linuxfoundation.org> References: <20251013144315.184275491@linuxfoundation.org> User-Agent: quilt/0.69 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 5f9238530970f2993b23dd67fdaffc552a2d2e98 ] If the receive queue contains payload that was already received, __tcp_close() can send an unexpected RST. Refine the code to take tp->copied_seq into account, as we already do in tcp recvmsg(). Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet Reviewed-by: Neal Cardwell Reviewed-by: Kuniyuki Iwashima Reviewed-by: Jason Xing Link: https://patch.msgid.link/20250903084720.1168904-2-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/ipv4/tcp.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 40a2f172be2cb..7d824578f217a 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2786,8 +2786,8 @@ bool tcp_check_oom(struct sock *sk, int shift) void __tcp_close(struct sock *sk, long timeout) { + bool data_was_unread = false; struct sk_buff *skb; - int data_was_unread = 0; int state; WRITE_ONCE(sk->sk_shutdown, SHUTDOWN_MASK); @@ -2806,11 +2806,12 @@ void __tcp_close(struct sock *sk, long timeout) * reader process may not have drained the data yet! */ while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) { - u32 len = TCP_SKB_CB(skb)->end_seq - TCP_SKB_CB(skb)->seq; + u32 end_seq = TCP_SKB_CB(skb)->end_seq; if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) - len--; - data_was_unread += len; + end_seq--; + if (after(end_seq, tcp_sk(sk)->copied_seq)) + data_was_unread = true; __kfree_skb(skb); } -- 2.51.0