linux-kernel - RE: [PATCH 1/7] vfio/pci: Disable auto-enable of exclusive INTx IRQ

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <BL1PR11MB527189373E8756AA8697E8D78C202@BL1PR11MB5271.namprd11.prod.outlook.com>
Date: Thu, 7 Mar 2024 08:39:16 +0000
From: "Tian, Kevin" <kevin.tian@...el.com>
To: Alex Williamson <alex.williamson@...hat.com>
CC: "kvm@...r.kernel.org" <kvm@...r.kernel.org>, "eric.auger@...hat.com"
	<eric.auger@...hat.com>, "clg@...hat.com" <clg@...hat.com>, "Chatre,
 Reinette" <reinette.chatre@...el.com>, "linux-kernel@...r.kernel.org"
	<linux-kernel@...r.kernel.org>
Subject: RE: [PATCH 1/7] vfio/pci: Disable auto-enable of exclusive INTx IRQ

> From: Alex Williamson <alex.williamson@...hat.com>
> Sent: Thursday, March 7, 2024 5:15 AM
> 
> Currently for devices requiring masking at the irqchip for INTx, ie.
> devices without DisINTx support, the IRQ is enabled in request_irq()
> and subsequently disabled as necessary to align with the masked status
> flag.  This presents a window where the interrupt could fire between
> these events, resulting in the IRQ incrementing the disable depth twice.
> This would be unrecoverable for a user since the masked flag prevents
> nested enables through vfio.
> 
> Instead, invert the logic using IRQF_NO_AUTOEN such that exclusive INTx
> is never auto-enabled, then unmask as required.
> 
> Fixes: 89e1f7d4c66d ("vfio: Add PCI device driver")
> Signed-off-by: Alex Williamson <alex.williamson@...hat.com>

CC stable?