From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Christoffer Dall , Suzuki K Poulose , Marc Zyngier , Sasha Levin Subject: [PATCH 3.18 090/144] arm/arm64: KVM: Take mmap_sem in stage2_unmap_vm Date: Thu, 8 Nov 2018 13:51:01 -0800 Message-Id: <20181108215101.941288550@linuxfoundation.org> In-Reply-To: <20181108215054.826084593@linuxfoundation.org> References: <20181108215054.826084593@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit List-ID: 3.18-stable review patch. If anyone has any objections, please let me know. ------------------ [ Upstream commit 90f6e150e44a0dc3883110eeb3ab35d1be42b6bb ] We don't hold the mmap_sem while searching for the VMAs when we try to unmap each memslot for a VM. Fix this properly to avoid unexpected results. Fixes: commit 957db105c997 ("arm/arm64: KVM: Introduce stage2_unmap_vm") Cc: stable@vger.kernel.org # v3.19+ Reviewed-by: Christoffer Dall Signed-off-by: Suzuki K Poulose Signed-off-by: Marc Zyngier Signed-off-by: Sasha Levin --- arch/arm/kvm/mmu.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c index e506389d02fb..017d6d1e1766 100644 --- a/arch/arm/kvm/mmu.c +++ b/arch/arm/kvm/mmu.c @@ -760,6 +760,7 @@ void stage2_unmap_vm(struct kvm *kvm) int idx; idx = srcu_read_lock(&kvm->srcu); + down_read(¤t->mm->mmap_sem); spin_lock(&kvm->mmu_lock); slots = kvm_memslots(kvm); @@ -767,6 +768,7 @@ void stage2_unmap_vm(struct kvm *kvm) stage2_unmap_memslot(kvm, memslot); spin_unlock(&kvm->mmu_lock); + up_read(¤t->mm->mmap_sem); srcu_read_unlock(&kvm->srcu, idx); } -- 2.17.1