From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Zyngier Subject: [PATCH] KVM: arm/arm64: Fix HYP unmapping going off limits Date: Thu, 7 Dec 2017 11:45:45 +0000 Message-ID: <20171207114545.23845-1-marc.zyngier@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 42A3D49D35 for ; Thu, 7 Dec 2017 06:42:38 -0500 (EST) Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id wm1an1cJecJV for ; Thu, 7 Dec 2017 06:42:37 -0500 (EST) Received: from foss.arm.com (usa-sjc-mx-foss1.foss.arm.com [217.140.101.70]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 0A17449D20 for ; Thu, 7 Dec 2017 06:42:37 -0500 (EST) List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu To: kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org Cc: Andre Przywara List-Id: kvmarm@lists.cs.columbia.edu When we unmap the HYP memory, we try to be clever and unmap one PGD at a time. If we start with a non-PGD aligned address and try to unmap a whole PGD, things go horribly wrong in unmap_hyp_range (addr and end can never match, and it all goes really badly as we keep incrementing pgd and parse random memory as page tables...). The obvious fix is to let unmap_hyp_range do what it does best, which is to iterate over a range. Cc: stable@vger.kernel.org Reported-by: Andre Przywara Signed-off-by: Marc Zyngier --- virt/kvm/arm/mmu.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c index b36945d49986..b4b69c2d1012 100644 --- a/virt/kvm/arm/mmu.c +++ b/virt/kvm/arm/mmu.c @@ -509,8 +509,6 @@ static void unmap_hyp_range(pgd_t *pgdp, phys_addr_t start, u64 size) */ void free_hyp_pgds(void) { - unsigned long addr; - mutex_lock(&kvm_hyp_pgd_mutex); if (boot_hyp_pgd) { @@ -521,10 +519,10 @@ void free_hyp_pgds(void) if (hyp_pgd) { unmap_hyp_range(hyp_pgd, hyp_idmap_start, PAGE_SIZE); - for (addr = PAGE_OFFSET; virt_addr_valid(addr); addr += PGDIR_SIZE) - unmap_hyp_range(hyp_pgd, kern_hyp_va(addr), PGDIR_SIZE); - for (addr = VMALLOC_START; is_vmalloc_addr((void*)addr); addr += PGDIR_SIZE) - unmap_hyp_range(hyp_pgd, kern_hyp_va(addr), PGDIR_SIZE); + unmap_hyp_range(hyp_pgd, kern_hyp_va(PAGE_OFFSET), + (uintptr_t)high_memory - PAGE_OFFSET); + unmap_hyp_range(hyp_pgd, kern_hyp_va(VMALLOC_START), + VMALLOC_END - VMALLOC_START); free_pages((unsigned long)hyp_pgd, hyp_pgd_order); hyp_pgd = NULL; -- 2.14.2