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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CAAFAC433EF for ; Wed, 19 Jan 2022 17:54:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1356561AbiASRyz (ORCPT ); Wed, 19 Jan 2022 12:54:55 -0500 Received: from Galois.linutronix.de ([193.142.43.55]:43894 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1356555AbiASRyx (ORCPT ); Wed, 19 Jan 2022 12:54:53 -0500 From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1642614892; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=j48OiqF+488LZi7JMqvf6TLaBjphB/X2lw2UnP1NtLs=; b=gMNQkdLIP+ueySCXhg9+mdfW04oO7G4An7Ushr7CNP4JXe9ktx9OVAEQr3w2fn4+rXPiks cxrMcpVcZBQ4hhLCBwKZV+BnaImv4XNkCiD6Tda7cs6wmY0zYQ3c8KXKei3SVDpF/lV3Wk EEkO7FZJLufaZnwbiN1srN7azbvwcByYqLZIPOVgEtZgqhLUtWBuGygLTk+6uWrCPMS1th +n+ulXfRjG8Tu/tvslo5aN66mHF24vqJWKNND08wOF0FmqLH6Ox/3jVX1/LxJALe0YJqyW TbkJ0F/oGFPPnlTWL2lJeuds9Un+bQ2H2QTQsRHq+/E+uqJXUkBYibzVAU0MNA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1642614892; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=j48OiqF+488LZi7JMqvf6TLaBjphB/X2lw2UnP1NtLs=; b=Bo4bekqkZys9RFVKp1/vmPTAijbgczqGlxknOpuiRYRAddJ6OXQvM6EQUa4H/f3S3MDO6U NnfAj2jVvK4atkBQ== To: Marc Zyngier , Tong Zhang Cc: Jason Gunthorpe , open list , Bjorn Helgaas Subject: [PATCH] PCI/MSI: Prevent UAF in error path In-Reply-To: <877dawa70b.ffs@tglx> References: <20220117092759.1619771-1-ztong0001@gmail.com> <87ilui8yxt.wl-maz@kernel.org> <87h7a28uhj.wl-maz@kernel.org> <87iluh9kgx.ffs@tglx> <877dawa70b.ffs@tglx> Date: Wed, 19 Jan 2022 18:54:52 +0100 Message-ID: <87r1938vbn.ffs@tglx> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When the core MSI allocation fails, then the PCI/MSI code uses an already freed MSI descriptor to unmask the MSI mask register in order to bring it back into reset state. Remove MSI_FLAG_FREE_MSI_DESCS from the PCI/MSI irqdomain flags and let the PCI/MSI code free the MSI descriptors after usage. Fixes: 0f62d941acf9 ("genirq/msi: Provide msi_domain_alloc/free_irqs_descs_locked()") Reported-by: Tong Zhang Signed-off-by: Thomas Gleixner --- drivers/pci/msi/irqdomain.c | 4 ++-- drivers/pci/msi/legacy.c | 1 - 2 files changed, 2 insertions(+), 3 deletions(-) --- a/drivers/pci/msi/irqdomain.c +++ b/drivers/pci/msi/irqdomain.c @@ -28,6 +28,7 @@ void pci_msi_teardown_msi_irqs(struct pc msi_domain_free_irqs_descs_locked(domain, &dev->dev); else pci_msi_legacy_teardown_msi_irqs(dev); + msi_free_msi_descs(&dev->dev); } /** @@ -171,8 +172,7 @@ struct irq_domain *pci_msi_create_irq_do if (info->flags & MSI_FLAG_USE_DEF_CHIP_OPS) pci_msi_domain_update_chip_ops(info); - info->flags |= MSI_FLAG_ACTIVATE_EARLY | MSI_FLAG_DEV_SYSFS | - MSI_FLAG_FREE_MSI_DESCS; + info->flags |= MSI_FLAG_ACTIVATE_EARLY | MSI_FLAG_DEV_SYSFS; if (IS_ENABLED(CONFIG_GENERIC_IRQ_RESERVATION_MODE)) info->flags |= MSI_FLAG_MUST_REACTIVATE; --- a/drivers/pci/msi/legacy.c +++ b/drivers/pci/msi/legacy.c @@ -77,5 +77,4 @@ void pci_msi_legacy_teardown_msi_irqs(st { msi_device_destroy_sysfs(&dev->dev); arch_teardown_msi_irqs(dev); - msi_free_msi_descs(&dev->dev); }