Path: csiph.com!1.us.feeder.erje.net!feeder.erje.net!2.us.feeder.erje.net!newsfeed.fsmpi.rwth-aachen.de!newsfeed.straub-nv.de!news.unit0.net!news.panservice.it!bofh.it!news.nic.it!robomod From: Greg Kroah-Hartman Newsgroups: linux.kernel Subject: [PATCH 4.10 012/110] arm/arm64: KVM: Take mmap_sem in kvm_arch_prepare_memory_region Date: Mon, 10 Apr 2017 19:00:04 +0200 Message-ID: References: X-Mailer: git-send-email 2.12.2 User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: robomod@news.nic.it List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Approved: robomod@news.nic.it Lines: 65 Organization: linux.* mail to news gateway X-Original-Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ard Biesheuvel , Eric Auger , Christoffer Dall , Suzuki K Poulose , Marc Zyngier X-Original-Date: Mon, 10 Apr 2017 18:42:03 +0200 X-Original-Message-ID: <20170410164201.936306299@linuxfoundation.org> X-Original-References: <20170410164201.247583164@linuxfoundation.org> X-Original-Sender: linux-kernel-owner@vger.kernel.org Xref: csiph.com linux.kernel:1620342 4.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Marc Zyngier commit 72f310481a08db821b614e7b5d00febcc9064b36 upstream. We don't hold the mmap_sem while searching for VMAs (via find_vma), in kvm_arch_prepare_memory_region, which can end up in expected failures. Fixes: commit 8eef91239e57 ("arm/arm64: KVM: map MMIO regions at creation time") Cc: Ard Biesheuvel Cc: Eric Auger Reviewed-by: Christoffer Dall [ Handle dirty page logging failure case ] Signed-off-by: Suzuki K Poulose Signed-off-by: Marc Zyngier Signed-off-by: Greg Kroah-Hartman --- arch/arm/kvm/mmu.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) --- a/arch/arm/kvm/mmu.c +++ b/arch/arm/kvm/mmu.c @@ -1806,6 +1806,7 @@ int kvm_arch_prepare_memory_region(struc (KVM_PHYS_SIZE >> PAGE_SHIFT)) return -EFAULT; + down_read(¤t->mm->mmap_sem); /* * A memory region could potentially cover multiple VMAs, and any holes * between them, so iterate over all of them to find out if we can map @@ -1849,8 +1850,10 @@ int kvm_arch_prepare_memory_region(struc pa += vm_start - vma->vm_start; /* IO region dirty page logging not allowed */ - if (memslot->flags & KVM_MEM_LOG_DIRTY_PAGES) - return -EINVAL; + if (memslot->flags & KVM_MEM_LOG_DIRTY_PAGES) { + ret = -EINVAL; + goto out; + } ret = kvm_phys_addr_ioremap(kvm, gpa, pa, vm_end - vm_start, @@ -1862,7 +1865,7 @@ int kvm_arch_prepare_memory_region(struc } while (hva < reg_end); if (change == KVM_MR_FLAGS_ONLY) - return ret; + goto out; spin_lock(&kvm->mmu_lock); if (ret) @@ -1870,6 +1873,8 @@ int kvm_arch_prepare_memory_region(struc else stage2_flush_memslot(kvm, memslot); spin_unlock(&kvm->mmu_lock); +out: + up_read(¤t->mm->mmap_sem); return ret; }