From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 278D047A0A1; Tue, 16 Jun 2026 17:06:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781629616; cv=none; b=Wx33cU/APmnZhD8BZ9zMdQzJ9d1WcyvREWMpdjGVzbAh7Pf7rFGBl3GnZxBRgwY9q+QydpxitXuHtPxoQ0X4CAoSKdbhEtHj7ItBg6d2cBFzqvEppzJvA9Q17fDtzs75PQoKBUbsLA5Y9Cd1TohVYO8NWIgn/WqzFECxDO5N2kY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781629616; c=relaxed/simple; bh=Yga1l9INy/yJRKKlhafFEEbg71tXjDeedekrNFivyXk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=cSkggPckuLWFQmpBFtcQs3Nk3oDYlW5IEZ00AQ41rO2lPTHdLtN4wj91A/8Q908FNFNPPrE46eiGoDZhcTwp28sQOftKvlSUdxB9IEHPg+a5SLIs1LZncYi5IovvBuBEzpvNoCyyGQwqRvBfYrWvWTlJ0+D0FuMYipMUVfDkSqE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Dzdn7pt2; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Dzdn7pt2" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1BB301F000E9; Tue, 16 Jun 2026 17:06:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1781629615; bh=obxRrkf1F1yy7ra2qsmGE2fRBTEudjo6POHgLdvw0IQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Dzdn7pt2IKbY8dLt6/FEVyE13TEbaw0ZxJArlE1Wv7d1VJ1oXroH+g0qSISz20sq2 3ug2EqwMyVYviJFed6aHJ4QXyXjn64Nudvj1ntmEWMuYx5z5bSXWI0HNEombkDyd0c NBfYR2wSxA9heLkPEm/DamDNaJw7fC6gWhSOgIXY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Raf Dickson , Stefano Garzarella , Paolo Abeni Subject: [PATCH 6.6 320/452] vsock/vmci: fix sk_ack_backlog leak on failed handshake Date: Tue, 16 Jun 2026 20:29:07 +0530 Message-ID: <20260616145134.265870366@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260616145117.796205997@linuxfoundation.org> References: <20260616145117.796205997@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: Raf Dickson commit c05fa14db43ebef3bd862ca9d073981c0358b3f0 upstream. When vmci_transport_recv_connecting_server() returns an error, vmci_transport_recv_listen() calls vsock_remove_pending() but never calls sk_acceptq_removed(). This leaves sk_ack_backlog incremented permanently. Repeated handshake failures (malformed packets, queue pair alloc failure, event subscribe failure) cause sk_ack_backlog to climb toward sk_max_ack_backlog. Once it reaches the limit the listener permanently refuses all new connections with -ECONNREFUSED, a silent denial of service requiring a process restart to recover. The two existing sk_acceptq_removed() calls in af_vsock.c do not cover this path: line 764 checks vsock_is_pending() which returns false after vsock_remove_pending(), and line 1889 is only reached on successful accept(). Fix by balancing sk_acceptq_added() with sk_acceptq_removed() on the error path. Fixes: d021c344051a ("VSOCK: Introduce VM Sockets") Cc: stable@vger.kernel.org Signed-off-by: Raf Dickson Acked-by: Stefano Garzarella Link: https://patch.msgid.link/20260526104356.469928-1-rafdog35@gmail.com Signed-off-by: Paolo Abeni Signed-off-by: Greg Kroah-Hartman --- net/vmw_vsock/vmci_transport.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/net/vmw_vsock/vmci_transport.c +++ b/net/vmw_vsock/vmci_transport.c @@ -972,8 +972,10 @@ static int vmci_transport_recv_listen(st err = -EINVAL; } - if (err < 0) + if (err < 0) { vsock_remove_pending(sk, pending); + sk_acceptq_removed(sk); + } release_sock(pending); vmci_transport_release_pending(pending);