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From: Sean Christopherson <sean.j.christopherson@intel.com>
To: Qian Cai <cai@lca.pw>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
	kvm@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>,
	Peter Xu <peterx@redhat.com>, Marc Zyngier <maz@kernel.org>,
	Christoffer Dall <christoffer.dall@arm.com>
Subject: Re: slab-out-of-bounds due to "KVM: Dynamically size memslot array based on number of used slots"
Date: Fri, 20 Mar 2020 06:53:46 -0700	[thread overview]
Message-ID: <20200320135346.GA16533@linux.intel.com> (raw)
In-Reply-To: <5FF6AF4E-EB99-4111-BBB2-FE09FFBEF5C4@lca.pw>

On Fri, Mar 20, 2020 at 09:49:03AM -0400, Qian Cai wrote:
> 
> 
> > On Mar 20, 2020, at 12:34 AM, Sean Christopherson <sean.j.christopherson@intel.com> wrote:
> > 
> > On Thu, Mar 19, 2020 at 11:59:23PM -0400, Qian Cai wrote:
> >> Reverted the linux-next commit 36947254e5f98 (“KVM: Dynamically size memslot array based on number of used slots”)
> >> fixed illegal slab object redzone accesses.
> >> 
> >> [6727.939776][ T1818] BUG: KASAN: slab-out-of-bounds in gfn_to_hva+0xc1/0x2b0 [kvm]
> >> search_memslots at include/linux/kvm_host.h:1035
> > 
> > Drat.  I'm guessing lru_slot is out of range after a memslot is deleted.
> > This should fix the issue, though it may not be the most proper fix, e.g.
> > it might be better to reset lru_slot when deleting a memslot.  I'll try and
> > reproduce tomorrow, unless you can confirm this does the trick.
> 
> It works fine.

Thanks!  I'll send a proper patch in a bit, tweaking a selftest to try and
hit this as well.

  reply	other threads:[~2020-03-20 13:53 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-20  3:59 slab-out-of-bounds due to "KVM: Dynamically size memslot array based on number of used slots" Qian Cai
2020-03-20  4:34 ` Sean Christopherson
2020-03-20 13:49   ` Qian Cai
2020-03-20 13:53     ` Sean Christopherson [this message]
2020-03-20 16:08       ` Peter Xu

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