linux-kernel - [PATCH 4.11 168/197] kvm: arm/arm64: Force reading uncached stage2 PGD

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: <20170523200838.515112956@linuxfoundation.org>
Date:   Tue, 23 May 2017 22:08:49 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Marc Zyngier <marc.zyngier@....com>,
        Suzuki K Poulose <suzuki.poulose@....com>,
        Christoffer Dall <cdall@...aro.org>
Subject: [PATCH 4.11 168/197] kvm: arm/arm64: Force reading uncached stage2 PGD

4.11-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Suzuki K Poulose <suzuki.poulose@....com>

commit 2952a6070e07ebdd5896f1f5b861acad677caded upstream.

Make sure we don't use a cached value of the KVM stage2 PGD while
resetting the PGD.

Cc: Marc Zyngier <marc.zyngier@....com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@....com>
Reviewed-by: Christoffer Dall <cdall@...aro.org>
Signed-off-by: Christoffer Dall <cdall@...aro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 arch/arm/kvm/mmu.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/arm/kvm/mmu.c
+++ b/arch/arm/kvm/mmu.c
@@ -844,7 +844,7 @@ void kvm_free_stage2_pgd(struct kvm *kvm
 	spin_lock(&kvm->mmu_lock);
 	if (kvm->arch.pgd) {
 		unmap_stage2_range(kvm, 0, KVM_PHYS_SIZE);
-		pgd = kvm->arch.pgd;
+		pgd = READ_ONCE(kvm->arch.pgd);
 		kvm->arch.pgd = NULL;
 	}
 	spin_unlock(&kvm->mmu_lock);