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 B79F6330B1E; Fri, 17 Oct 2025 15:47:49 +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=1760716069; cv=none; b=osX2wlkwq+0l3GOhuHNDsr8B2kwS11g2T0AJLqs1MhrJXDW63U5Mzkl/s0gQZfUSuk6FQ8NcalNKxQ338/yGYzzp5N9EPoyClCWVAELdGxZJIhevw8Rf9m1x7hFO7Bk5g3JoqIaYxSGf1xD/JQLpvBSVnR28k2Gy404vF8/FC0U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760716069; c=relaxed/simple; bh=YYCrFpBOyPkgRohNCK964Be7iJBFZFh1syVDvpp0mag=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=MW+8GnYU+NRVQdyyCC48Z0iDmS64hj4yo46zGBU864SKCOzdJvREXcoIOJO6BHf2AZIr8XLOUFYWTU+DQOZ9MTx+Qv+AQcM5Hv8vfQ5yz/mzDHL3ooLPbhAGrFpTK/rFIiwK6gO30+h3VoqHbYiDaUQg5fkZ03NPoVAAtadNS/w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=DRXfDxhL; 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="DRXfDxhL" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E7AF7C4CEFE; Fri, 17 Oct 2025 15:47:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1760716069; bh=YYCrFpBOyPkgRohNCK964Be7iJBFZFh1syVDvpp0mag=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DRXfDxhLhGwX3D9z8VsXmFPdbYFh7anrMuVPDa89uXwWz25X5ME+AsiNacZ7h9hyD +5v2eopHflv2oR7LCyxxXwYak2h6s/iadM32kXaDt0TE/FQw3RFE6kH3YmdLl1PNzA Jt0G5Vgsp9z1tzScyosiC4g+nojQ1NRSVYojDuFQ= 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 5.15 062/276] tcp: fix __tcp_close() to only send RST when required Date: Fri, 17 Oct 2025 16:52:35 +0200 Message-ID: <20251017145144.753755014@linuxfoundation.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251017145142.382145055@linuxfoundation.org> References: <20251017145142.382145055@linuxfoundation.org> User-Agent: quilt/0.69 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 5.15-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 9508e2c90b840..b3d373372e841 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2747,8 +2747,8 @@ 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); @@ -2767,11 +2767,12 @@ 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