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 B9B4E30C626; Mon, 13 Oct 2025 15:12:14 +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=1760368334; cv=none; b=gvmP/7b/c8utBQ/JOPB8ApK024lUeDT+3LwA0r9Bx9B9Hv07jjVNkzPJ7OhRW84K/IMsBFPCHYPR3m9LxHjw29r/r510l1DDAs8/LLuCp1zcdnzgrHjgofWVMLhEtB+YsPrkUwdX6XU9TQqFLgmcl8qis2joRLa4aGm63eXk/L8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760368334; c=relaxed/simple; bh=ebop7vL4RDNGc9OaM3jNZeMfNDxQ47GdSQKgEXULDII=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Wwpwk85J49V7cm7Cb83kv9WRxLeCKnm6DasZREakrprZxcAiSC5GhSRLQx3pTF/HFRlmhxJFA3eUmZsVh/OZvniWcgyU6xEl8/k7ygPToTIals0AtvfyDjIwzNCOgTnZujIJTwl8zyrOZjdxaOUog+qsJ9bASi9rl5gbHS+U3ts= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ZZTl3OPq; 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="ZZTl3OPq" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 487A0C4CEE7; Mon, 13 Oct 2025 15:12:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1760368334; bh=ebop7vL4RDNGc9OaM3jNZeMfNDxQ47GdSQKgEXULDII=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZZTl3OPqy9Au5po0GBAsr5iQFV1wV8HL23DMJyZGLmdDxhGECMqVFzRAKPID12hlk 0BfYV/u057dt76jd9fRebuzoUz21cY6MfNy2gOZbFCb/2y0b9fCAs+CN3Om2kWhx4E u2C8YTAV7kGqSai/YmFVNItpkO2Gb0rWWVhCRB+s= 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 6.12 125/262] tcp: fix __tcp_close() to only send RST when required Date: Mon, 13 Oct 2025 16:44:27 +0200 Message-ID: <20251013144330.626693106@linuxfoundation.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251013144326.116493600@linuxfoundation.org> References: <20251013144326.116493600@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 6.12-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 988992ff898b3..739931aabb4e3 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -3058,8 +3058,8 @@ bool tcp_check_oom(const 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); @@ -3078,11 +3078,12 @@ 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