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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 0944AC3A59F for ; Thu, 29 Aug 2019 18:14:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D39122189D for ; Thu, 29 Aug 2019 18:14:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1567102460; bh=S/uUICgvSilsGtYuYVeoMlz2yDoqpI2JswWuw36fMiE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=enlm0NuVuPyx8omjMv6axLChEC9Z7l77hyoQkojhGta6yrehH065W4A/vit5OmJxm Q2nO0vIujcrRLwB5UGWvKkxqQMzq78otHBc8Hv7twNCCYl2bEpuHBdZVOJIvEg+e44 3xbgkOHWYMV7ldBsXl7NkV5TTc1Oi2PumPIwyz68= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728737AbfH2SOH (ORCPT ); Thu, 29 Aug 2019 14:14:07 -0400 Received: from mail.kernel.org ([198.145.29.99]:55662 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728646AbfH2SN5 (ORCPT ); Thu, 29 Aug 2019 14:13:57 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id DD78223426; Thu, 29 Aug 2019 18:13:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1567102436; bh=S/uUICgvSilsGtYuYVeoMlz2yDoqpI2JswWuw36fMiE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QNIEK5jCHnPc2kiXXSaoETxgnmNt9gMqhUtQNgi+Go1EBKZkOnUyYeByiiytqtFOM p2PfbMwEtx5tFF98LD4iFy69U9qMmHzOXj4sq2JYGSEPBHDVJ2zQVPlE20cvf31Fs0 fxAdq6vhezm1eVIXzWuhtS+SK7BpM37/MVyiZvE8= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: David Howells , syzbot+193e29e9387ea5837f1d@syzkaller.appspotmail.com, Sasha Levin , linux-afs@lists.infradead.org, netdev@vger.kernel.org Subject: [PATCH AUTOSEL 5.2 25/76] rxrpc: Fix local endpoint replacement Date: Thu, 29 Aug 2019 14:12:20 -0400 Message-Id: <20190829181311.7562-25-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190829181311.7562-1-sashal@kernel.org> References: <20190829181311.7562-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: David Howells [ Upstream commit b00df840fb4004b7087940ac5f68801562d0d2de ] When a local endpoint (struct rxrpc_local) ceases to be in use by any AF_RXRPC sockets, it starts the process of being destroyed, but this doesn't cause it to be removed from the namespace endpoint list immediately as tearing it down isn't trivial and can't be done in softirq context, so it gets deferred. If a new socket comes along that wants to bind to the same endpoint, a new rxrpc_local object will be allocated and rxrpc_lookup_local() will use list_replace() to substitute the new one for the old. Then, when the dying object gets to rxrpc_local_destroyer(), it is removed unconditionally from whatever list it is on by calling list_del_init(). However, list_replace() doesn't reset the pointers in the replaced list_head and so the list_del_init() will likely corrupt the local endpoints list. Fix this by using list_replace_init() instead. Fixes: 730c5fd42c1e ("rxrpc: Fix local endpoint refcounting") Reported-by: syzbot+193e29e9387ea5837f1d@syzkaller.appspotmail.com Signed-off-by: David Howells Signed-off-by: Sasha Levin --- net/rxrpc/local_object.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/rxrpc/local_object.c b/net/rxrpc/local_object.c index 9798159ee65fa..918bffca3ddb6 100644 --- a/net/rxrpc/local_object.c +++ b/net/rxrpc/local_object.c @@ -283,7 +283,7 @@ struct rxrpc_local *rxrpc_lookup_local(struct net *net, goto sock_error; if (cursor != &rxnet->local_endpoints) - list_replace(cursor, &local->link); + list_replace_init(cursor, &local->link); else list_add_tail(&local->link, cursor); age = "new"; -- 2.20.1