From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 76566C64E75 for ; Mon, 23 Nov 2020 12:30:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0F52A20857 for ; Mon, 23 Nov 2020 12:30:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="FyEeMsJ9" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730700AbgKWMaJ (ORCPT ); Mon, 23 Nov 2020 07:30:09 -0500 Received: from mail.kernel.org ([198.145.29.99]:40758 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730680AbgKWMaB (ORCPT ); Mon, 23 Nov 2020 07:30:01 -0500 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3E13320857; Mon, 23 Nov 2020 12:30:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1606134600; bh=AOB30L8ww43v7wr6brdJId+AsaRQj64ltkSfM+gFsw8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FyEeMsJ9u4F9F9XBypC30J0Mp442l/x/mGVQ1Ho2O3hzwxBg+ySG4aeayQp4LtLzb OYIGI6y48la3nI3MkQh1aocEBpB8kjyQQkHUvh+/1CN/iqkabziM2tD6MkLOnaCkCf S9OTkRH4aE86pdFI4QDlAwl5JEIAZpidQ6OipaNg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Martin Schiller , Xie He , Jakub Kicinski Subject: [PATCH 4.19 17/91] net: x25: Increase refcnt of "struct x25_neigh" in x25_rx_call_request Date: Mon, 23 Nov 2020 13:21:37 +0100 Message-Id: <20201123121810.143254246@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201123121809.285416732@linuxfoundation.org> References: <20201123121809.285416732@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Xie He [ Upstream commit 4ee18c179e5e815fa5575e0d2db0c05795a804ee ] The x25_disconnect function in x25_subr.c would decrease the refcount of "x25->neighbour" (struct x25_neigh) and reset this pointer to NULL. However, the x25_rx_call_request function in af_x25.c, which is called when we receive a connection request, does not increase the refcount when it assigns the pointer. Fix this issue by increasing the refcount of "struct x25_neigh" in x25_rx_call_request. This patch fixes frequent kernel crashes when using AF_X25 sockets. Fixes: 4becb7ee5b3d ("net/x25: Fix x25_neigh refcnt leak when x25 disconnect") Cc: Martin Schiller Signed-off-by: Xie He Link: https://lore.kernel.org/r/20201112103506.5875-1-xie.he.0141@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- net/x25/af_x25.c | 1 + 1 file changed, 1 insertion(+) --- a/net/x25/af_x25.c +++ b/net/x25/af_x25.c @@ -1049,6 +1049,7 @@ int x25_rx_call_request(struct sk_buff * makex25->lci = lci; makex25->dest_addr = dest_addr; makex25->source_addr = source_addr; + x25_neigh_hold(nb); makex25->neighbour = nb; makex25->facilities = facilities; makex25->dte_facilities= dte_facilities;