From: Al Viro <viro@ZenIV.linux.org.uk>
To: Gregory Haskins <ghaskins@novell.com>
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
avi@redhat.com, davidel@xmailserver.org
Subject: Re: [KVM PATCH v3 2/2] kvm: add support for irqfd via eventfd-notification interface
Date: Sun, 3 May 2009 07:44:32 +0100 [thread overview]
Message-ID: <20090503064432.GS8633@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20090427183334.6646.90800.stgit@dev.haskins.net>
On Mon, Apr 27, 2009 at 02:33:34PM -0400, Gregory Haskins wrote:
> + /* We re-use eventfd for irqfd */
> + fd = sys_eventfd2(0, 0);
> + if (fd < 0) {
> + ret = fd;
> + goto fail;
> + }
> +
> + /* We maintain a reference to eventfd for the irqfd lifetime */
> + file = eventfd_fget(fd);
> + if (IS_ERR(file)) {
> + ret = PTR_ERR(file);
> + goto fail;
> + }
> +
> + irqfd->file = file;
This is just plain wrong. You have no promise whatsoever that caller of
that sucker won't race with e.g. dup2(). IOW, you can't assume that
file will be of the expected kind.
next prev parent reply other threads:[~2009-05-03 6:44 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-04-27 18:33 [KVM PATCH v3 0/2] irqfd Gregory Haskins
2009-04-27 18:33 ` [KVM PATCH v3 1/2] eventfd: export fget and signal interfaces for module use Gregory Haskins
2009-04-27 18:33 ` [KVM PATCH v3 2/2] kvm: add support for irqfd via eventfd-notification interface Gregory Haskins
2009-04-30 13:07 ` Michael S. Tsirkin
2009-05-03 16:59 ` Avi Kivity
2009-05-03 19:04 ` Michael S. Tsirkin
2009-05-03 19:17 ` Avi Kivity
2009-05-03 19:25 ` Michael S. Tsirkin
2009-05-03 6:44 ` Al Viro [this message]
2009-05-03 18:07 ` Davide Libenzi
2009-05-03 19:01 ` Al Viro
2009-05-03 19:22 ` file descriptor abuses Al Viro
2009-05-03 20:11 ` [KVM PATCH v3 2/2] kvm: add support for irqfd via eventfd-notification interface Davide Libenzi
2009-05-03 20:31 ` Al Viro
2009-04-29 6:10 ` [KVM PATCH v3 0/2] irqfd Andrew Morton
2009-04-29 8:18 ` Avi Kivity
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