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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,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 B1879C04EB8 for ; Sun, 2 Dec 2018 11:04:02 +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 270AB2081C for ; Sun, 2 Dec 2018 11:04:02 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 270AB2081C 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 4374xr0Q3fzDqMh for ; Sun, 2 Dec 2018 22:04:00 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au 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)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4374vf0934zDqcl for ; Sun, 2 Dec 2018 22:02:06 +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 4374vc6qfmz9sD4; Sun, 2 Dec 2018 22:02:04 +1100 (AEDT) X-powerpc-patch-notification: thanks X-powerpc-patch-commit: 78e7b15e17ac175e7eed9e21c6f92d03d3b0a6fa X-Patchwork-Hint: ignore In-Reply-To: <20181128032048.11665-2-radu.rendec@gmail.com> To: Radu Rendec , linuxppc-dev@lists.ozlabs.org From: Michael Ellerman Subject: Re: [1/1] Fix NULL pointer access in PowerPC MSI teardown code Message-Id: <4374vc6qfmz9sD4@ozlabs.org> Date: Sun, 2 Dec 2018 22:02:04 +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: Radu Rendec , Paul Mackerras Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Wed, 2018-11-28 at 03:20:48 UTC, Radu Rendec wrote: > The arch_teardown_msi_irqs() function assumes that controller ops > pointers were already checked in arch_setup_msi_irqs(), but this > assumption is wrong: arch_teardown_msi_irqs() can be called even when > arch_setup_msi_irqs() returns an error (-ENOSYS). > > This can happen in the following scenario: > > * msi_capability_init() calls pci_msi_setup_msi_irqs() > * pci_msi_setup_msi_irqs() returns -ENOSYS > * msi_capability_init() notices the error and calls free_msi_irqs() > * free_msi_irqs() calls pci_msi_teardown_msi_irqs() > > This is easier to see when CONFIG_PCI_MSI_IRQ_DOMAIN is not set and > pci_msi_setup_msi_irqs() and pci_msi_teardown_msi_irqs() are just > aliases to arch_setup_msi_irqs() and arch_teardown_msi_irqs(). > > The call to free_msi_irqs() upon pci_msi_setup_msi_irqs() failure seems > legit, as it does additional cleanup; e.g. list_del(&entry->list) and > kfree(entry) inside free_msi_irqs() do happen (MSI descriptors are > allocated before pci_msi_setup_msi_irqs() is called and need to be > cleaned up if that fails). > > Signed-off-by: Radu Rendec Applied to powerpc fixes, thanks. https://git.kernel.org/powerpc/c/78e7b15e17ac175e7eed9e21c6f92d cheers