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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 A3539C352A3 for ; Mon, 10 Feb 2020 13:37:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 73F112070A for ; Mon, 10 Feb 2020 13:37:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581341837; bh=c3tgSngV8g/zazarzdeUexL1RfBUdv/2ktY5IS8162Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=RzjzNyIV4P5Dh+NVCk2yHlLMr4K0/065ZkQhHaVEO1mHpdXbxhflK6jf1zYOLTfcl tzXlDsU6B6i2AFLzHtI29BILGaPAdy7v+wALqzCFQ1K7Lx32Rt018LJCVnAFoT35c7 dPIrgLXTRzKI7dinQFKmZeR8PsKdHdcq4hHciWCU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730558AbgBJNhN (ORCPT ); Mon, 10 Feb 2020 08:37:13 -0500 Received: from mail.kernel.org ([198.145.29.99]:51356 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727652AbgBJMfE (ORCPT ); Mon, 10 Feb 2020 07:35:04 -0500 Received: from localhost (unknown [209.37.97.194]) (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 80C3B21739; Mon, 10 Feb 2020 12:35:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581338103; bh=c3tgSngV8g/zazarzdeUexL1RfBUdv/2ktY5IS8162Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=umj0U9uG++eHoe1w/sOorDNo/SHdOR4wyy9Rndpg1dSTygBevZSfAQOQAiBwgIzJc 6ob3uYQPM79dZzto52bLB5xv4PAonHuOO1+Qmu2MEXNFgEXAYwvpPODvizyIPW0YXE sS4bWq4jiZtr65cjZtdxhSyim3v8GPz3d0pKleF4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, David Howells Subject: [PATCH 4.19 022/195] rxrpc: Fix use-after-free in rxrpc_put_local() Date: Mon, 10 Feb 2020 04:31:20 -0800 Message-Id: <20200210122307.998807279@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200210122305.731206734@linuxfoundation.org> References: <20200210122305.731206734@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: David Howells [ Upstream commit fac20b9e738523fc884ee3ea5be360a321cd8bad ] Fix rxrpc_put_local() to not access local->debug_id after calling atomic_dec_return() as, unless that returned n==0, we no longer have the right to access the object. Fixes: 06d9532fa6b3 ("rxrpc: Fix read-after-free in rxrpc_queue_local()") Signed-off-by: David Howells Signed-off-by: Greg Kroah-Hartman --- net/rxrpc/local_object.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/net/rxrpc/local_object.c +++ b/net/rxrpc/local_object.c @@ -368,11 +368,14 @@ void rxrpc_queue_local(struct rxrpc_loca void rxrpc_put_local(struct rxrpc_local *local) { const void *here = __builtin_return_address(0); + unsigned int debug_id; int n; if (local) { + debug_id = local->debug_id; + n = atomic_dec_return(&local->usage); - trace_rxrpc_local(local->debug_id, rxrpc_local_put, n, here); + trace_rxrpc_local(debug_id, rxrpc_local_put, n, here); if (n == 0) call_rcu(&local->rcu, rxrpc_local_rcu);