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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,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 67DF9C2BCA1 for ; Fri, 7 Jun 2019 13:11:10 +0000 (UTC) Received: from lists.ozlabs.org (unknown [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 C876B208E3 for ; Fri, 7 Jun 2019 13:11:09 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C876B208E3 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 45L2wB4gt9zDqD0 for ; Fri, 7 Jun 2019 23:11:06 +1000 (AEST) Received: from ozlabs.org (bilbo.ozlabs.org [203.11.71.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 45L2rm2k5XzDqwC for ; Fri, 7 Jun 2019 23:08:08 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mail.ozlabs.org (Postfix) with ESMTPSA id 45L2rl70tlz9sNR; Fri, 7 Jun 2019 23:08:07 +1000 (AEST) From: Michael Ellerman To: Nathan Lynch , linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH] powerpc/pseries: fix oops in hotplug memory notifier In-Reply-To: <20190607050407.25444-1-nathanl@linux.ibm.com> References: <20190607050407.25444-1-nathanl@linux.ibm.com> Date: Fri, 07 Jun 2019 23:08:01 +1000 Message-ID: <87tvd1h7bi.fsf@concordia.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain 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: , Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Nathan Lynch writes: > During post-migration device tree updates, we can oops in > pseries_update_drconf_memory if the source device tree has an > ibm,dynamic-memory-v2 property and the destination has a > ibm,dynamic_memory (v1) property. The notifier processes an "update" > for the ibm,dynamic-memory property but it's really an add in this > scenario. So make sure the old property object is there before > dereferencing it. > > Signed-off-by: Nathan Lynch Can you pinpoint a commit that introduced the bug? Should we backport this to stable? Perhaps? Fixes: 2b31e3aec1db ("powerpc/drmem: Add support for ibm, dynamic-memory-v2 property") cheers > diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c b/arch/powerpc/platforms/pseries/hotplug-memory.c > index 47087832f8b2..e6bd172bcf30 100644 > --- a/arch/powerpc/platforms/pseries/hotplug-memory.c > +++ b/arch/powerpc/platforms/pseries/hotplug-memory.c > @@ -980,6 +980,9 @@ static int pseries_update_drconf_memory(struct of_reconfig_data *pr) > if (!memblock_size) > return -EINVAL; > > + if (!pr->old_prop) > + return 0; > + > p = (__be32 *) pr->old_prop->value; > if (!p) > return -EINVAL; > -- > 2.20.1