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 D9FEB313520; Mon, 27 Oct 2025 18:41:43 +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=1761590503; cv=none; b=ozFiykg+mmxthMpKr06TgsPG6qApO7IQwrCmxyazEFPoJ5/sJ7ETinJK9qgcfAU1D+iCRN7c552yaLDdtEM8ss73ZD5cPIil4dAyrcJ9HSYcNyeMYGM7CNOZ3TFOSv9BE2G7NAw0G1FD0ADNwPb5qd7sNmiqHN1OBCQDQqL0/QY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761590503; c=relaxed/simple; bh=tmM4SBvXnBX9OwY5DKAgI0KWq81V4UfrR69REABzu0g=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=JtKHalA0md2t/j1if9U2Sbk96acqY++jo05M4zMbGZi61S8f/q9MWksYA+eaCNVflI9findvjDtNyydk22ypmTjXd95A8x6+3gmTv56Ji6S4g28zOqwwEWV2xT/km8LPC7dgciqWcD9Q94kFZg2LZsTdCKiV82GkgBBHDa9IVls= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=BGQ6GX+P; 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="BGQ6GX+P" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6F79AC4CEF1; Mon, 27 Oct 2025 18:41:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1761590503; bh=tmM4SBvXnBX9OwY5DKAgI0KWq81V4UfrR69REABzu0g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BGQ6GX+P9sG/GgiVxZDP9y6XiRDz1LBYMRfbRMITRwsRmjNcrQvy0ptIvBR+6WAsq LXFcz01Mxypi0C0e309Bz/Fsf1kvIwzrn8Oj3VutcwQKx5ePLfvLVFh8O2R6Q1l4dL oc6XZ3cJ/VlJMSYadvlsF50f3BkhoBSDXt4H/mtY= 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 5.4 040/224] tcp: fix __tcp_close() to only send RST when required Date: Mon, 27 Oct 2025 19:33:06 +0100 Message-ID: <20251027183510.079800548@linuxfoundation.org> X-Mailer: git-send-email 2.51.1 In-Reply-To: <20251027183508.963233542@linuxfoundation.org> References: <20251027183508.963233542@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 5.4-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 cc0efcb4a553c..a0a5590573b03 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2359,8 +2359,8 @@ 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); @@ -2379,11 +2379,12 @@ 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