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=-8.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 1E4C0C18E5B for ; Tue, 17 Mar 2020 13:33:11 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 97AF9205ED for ; Tue, 17 Mar 2020 13:33:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 97AF9205ED Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 48hYyX0pYPzDqZp for ; Wed, 18 Mar 2020 00:33:08 +1100 (AEDT) Received: from ozlabs.org (bilbo.ozlabs.org [IPv6:2401:3900:2:1::2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 48hYYH5kFCzDqdp for ; Wed, 18 Mar 2020 00:14:43 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au Received: by ozlabs.org (Postfix, from userid 1034) id 48hYYG1y3Lz9sSL; Wed, 18 Mar 2020 00:14:40 +1100 (AEDT) X-powerpc-patch-notification: thanks X-powerpc-patch-commit: d0a72efac89d1c35ac55197895201b7b94c5e6ef In-Reply-To: <20200206062622.28235-1-oohall@gmail.com> To: Oliver O'Halloran , linuxppc-dev@lists.ozlabs.org From: Michael Ellerman Subject: Re: [PATCH 1/2] cpufreq/powernv: Fix use-after-free Message-Id: <48hYYG1y3Lz9sSL@ozlabs.org> Date: Wed, 18 Mar 2020 00:14:40 +1100 (AEDT) X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Vaidyanathan Srinivasan , Oliver O'Halloran Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Thu, 2020-02-06 at 06:26:21 UTC, Oliver O'Halloran wrote: > The cpufreq driver has a use-after-free that we can hit if: > > a) There's an OCC message pending when the notifier is registered, and > b) The cpufreq driver fails to register with the core. > > When a) occurs the notifier schedules a workqueue item to handle the > message. The backing work_struct is located on chips[].throttle and when b) > happens we clean up by freeing the array. Once we get to the (now free) > queued item and the kernel crashes. > > Cc: Vaidyanathan Srinivasan > Fixes: c5e29ea ("cpufreq: powernv: Fix bugs in powernv_cpufreq_{init/exit}") > Signed-off-by: Oliver O'Halloran Series applied to powerpc next, thanks. https://git.kernel.org/powerpc/c/d0a72efac89d1c35ac55197895201b7b94c5e6ef cheers