linux-kernel - Re: [PATCH] kvm: don't take vcpu mutex for obviously invalid vcpu ioctls

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:	Tue, 23 Sep 2014 09:49:18 +0300
From:	Gleb Natapov <gleb@...nel.org>
To:	Paolo Bonzini <pbonzini@...hat.com>
Cc:	Christian Borntraeger <borntraeger@...ibm.com>,
	David Matlack <dmatlack@...gle.com>, kvm@...r.kernel.org,
	linux-kernel@...r.kernel.org, Marcelo Tosatti <mtosatti@...hat.com>
Subject: Re: [PATCH] kvm: don't take vcpu mutex for obviously invalid vcpu
 ioctls

On Mon, Sep 22, 2014 at 09:29:19PM +0200, Paolo Bonzini wrote:
> Il 22/09/2014 21:20, Christian Borntraeger ha scritto:
> > "while using trinity to fuzz KVM, we noticed long stalls on invalid ioctls. Lets bail out early on invalid ioctls". or similar?
> 
> Okay.  David, can you explain how you found it so that I can make up my
> mind?
> 
> Gleb and Marcelo, a fourth and fifth opinion? :)
> 
I agree with Christian that simpler fix is better here.
The overhead is minimal. If we ever notice this overhead
we can revert the patch all together since the problem it
fixes can only be inflicted on userspace by itself and there
are myriads other ways userspace can hurt itself.

--
			Gleb.
--
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/