linux-kernel - Re: [PATCH v5 1/4] kvm: Extend irqfd to support level interrupts

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]

Date:	Wed, 18 Jul 2012 00:26:12 +0300
From:	"Michael S. Tsirkin" <mst@...hat.com>
To:	Alex Williamson <alex.williamson@...hat.com>
Cc:	avi@...hat.com, gleb@...hat.com, kvm@...r.kernel.org,
	linux-kernel@...r.kernel.org, jan.kiszka@...mens.com
Subject: Re: [PATCH v5 1/4] kvm: Extend irqfd to support level interrupts

On Mon, Jul 16, 2012 at 02:33:47PM -0600, Alex Williamson wrote:
> @@ -96,6 +183,9 @@ irqfd_shutdown(struct work_struct *work)
>  	 * It is now safe to release the object's resources
>  	 */
>  	eventfd_ctx_put(irqfd->eventfd);
> +
> +	_irq_source_put(irqfd->source);
> +
>  	kfree(irqfd);
>  }
>  

Hang on, this is a bug I think. This is done asynchronously.  So this
means that I can assign MAX number of irqfds, then close one, and now
assign will fail because deassign did not get freed.

Maybe we can solve this by flushing wq before assign?
Looks a bit fragile but may be enough - need to document well.

-- 
MST
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/