Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754528AbdHVBXw (ORCPT ); Mon, 21 Aug 2017 21:23:52 -0400 Received: from szxga04-in.huawei.com ([45.249.212.190]:4975 "EHLO szxga04-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754252AbdHVBXu (ORCPT ); Mon, 21 Aug 2017 21:23:50 -0400 From: nixiaoming To: , CC: , , Subject: [PATCH] virt/kvm avoids oops by adding parameter checking Date: Tue, 22 Aug 2017 09:09:09 +0800 Message-ID: <20170822010909.103060-1-nixiaoming@huawei.com> X-Mailer: git-send-email 2.11.0.1 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.67.187.180] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020201.599B87A4.00B3,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2014-11-16 11:51:01, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: 5b77900cfeaa2fabdd98e137bd671032 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5585 Lines: 210 The error parameter passed through the external interface causes the system oops. So it is necessary to increase the parameter check for all EXPORT_SYMBOL_GPL example: void kvm_get_kvm(struct kvm *kvm) { refcount_inc(&kvm->users_count); /*oops if kvm == NULL */ } EXPORT_SYMBOL_GPL(kvm_get_kvm); Signed-off-by: nixiaoming --- virt/kvm/eventfd.c | 2 ++ virt/kvm/kvm_main.c | 52 +++++++++++++++++++++++++++++++++++++++++++++++++--- 2 files changed, 51 insertions(+), 3 deletions(-) diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c index f2ac53a..250200b 100644 --- a/virt/kvm/eventfd.c +++ b/virt/kvm/eventfd.c @@ -444,6 +444,8 @@ bool kvm_irq_has_notifier(struct kvm *kvm, unsigned irqchip, unsigned pin) { struct kvm_irq_ack_notifier *kian; int gsi, idx; + if (kvm == NULL) + return false; idx = srcu_read_lock(&kvm->irq_srcu); gsi = kvm_irq_map_chip_pin(kvm, irqchip, pin); diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 15252d7..3e25de0 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -150,6 +150,8 @@ bool kvm_is_reserved_pfn(kvm_pfn_t pfn) int vcpu_load(struct kvm_vcpu *vcpu) { int cpu; + if (vcpu == NULL) + return -EINVAL; if (mutex_lock_killable(&vcpu->mutex)) return -EINTR; @@ -163,6 +165,8 @@ EXPORT_SYMBOL_GPL(vcpu_load); void vcpu_put(struct kvm_vcpu *vcpu) { + if (vcpu == NULL) + return; preempt_disable(); kvm_arch_vcpu_put(vcpu); preempt_notifier_unregister(&vcpu->preempt_notifier); @@ -235,6 +239,8 @@ bool kvm_make_all_cpus_request(struct kvm *kvm, unsigned int req) #ifndef CONFIG_HAVE_KVM_ARCH_TLB_FLUSH_ALL void kvm_flush_remote_tlbs(struct kvm *kvm) { + if (kvm == NULL) + return; /* * Read tlbs_dirty before setting KVM_REQ_TLB_FLUSH in * kvm_make_all_cpus_request. @@ -269,6 +275,9 @@ int kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id) struct page *page; int r; + if (vcpu == NULL) + return -EINVAL; + mutex_init(&vcpu->mutex); vcpu->cpu = -1; vcpu->kvm = kvm; @@ -305,6 +314,8 @@ EXPORT_SYMBOL_GPL(kvm_vcpu_init); void kvm_vcpu_uninit(struct kvm_vcpu *vcpu) { + if (vcpu == NULL) + return; /* * no need for rcu_read_lock as VCPU_RUN is the only place that * will change the vcpu->pid pointer and on uninit all file @@ -779,12 +790,16 @@ static void kvm_destroy_vm(struct kvm *kvm) void kvm_get_kvm(struct kvm *kvm) { + if (kvm == NULL) + return; refcount_inc(&kvm->users_count); } EXPORT_SYMBOL_GPL(kvm_get_kvm); void kvm_put_kvm(struct kvm *kvm) { + if (kvm == NULL) + return; if (refcount_dec_and_test(&kvm->users_count)) kvm_destroy_vm(kvm); } @@ -938,6 +953,9 @@ int __kvm_set_memory_region(struct kvm *kvm, int as_id, id; enum kvm_mr_change change; + if (mem == NULL) + return -EINVAL; + r = check_memory_region_flags(mem); if (r) goto out; @@ -1121,6 +1139,9 @@ int kvm_get_dirty_log(struct kvm *kvm, unsigned long n; unsigned long any = 0; + if (log == NULL || is_dirty == NULL) + return -EINVAL; + as_id = log->slot >> 16; id = (u16)log->slot; if (as_id >= KVM_ADDRESS_SPACE_NUM || id >= KVM_USER_MEM_SLOTS) @@ -1178,6 +1199,9 @@ int kvm_get_dirty_log_protect(struct kvm *kvm, unsigned long *dirty_bitmap; unsigned long *dirty_bitmap_buffer; + if (log == NULL || is_dirty == NULL) + return -EINVAL; + as_id = log->slot >> 16; id = (u16)log->slot; if (as_id >= KVM_ADDRESS_SPACE_NUM || id >= KVM_USER_MEM_SLOTS) @@ -1996,6 +2020,8 @@ int kvm_write_guest_offset_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc, { struct kvm_memslots *slots = kvm_memslots(kvm); int r; + if (ghc == NULL) + return -EINVAL; gpa_t gpa = ghc->gpa + offset; BUG_ON(len + offset > ghc->len); @@ -2225,6 +2251,8 @@ EXPORT_SYMBOL_GPL(kvm_vcpu_block); bool kvm_vcpu_wake_up(struct kvm_vcpu *vcpu) { struct swait_queue_head *wqp; + if (vcpu == NULL) + return false; wqp = kvm_arch_vcpu_wq(vcpu); if (swait_active(wqp)) { @@ -2244,7 +2272,11 @@ EXPORT_SYMBOL_GPL(kvm_vcpu_wake_up); void kvm_vcpu_kick(struct kvm_vcpu *vcpu) { int me; - int cpu = vcpu->cpu; + int cpu; + + if (vcpu == NULL) + return; + cpu = vcpu->cpu; if (kvm_vcpu_wake_up(vcpu)) return; @@ -2264,6 +2296,9 @@ int kvm_vcpu_yield_to(struct kvm_vcpu *target) struct task_struct *task = NULL; int ret = 0; + if (target == NULL) + return -EINVAL; + rcu_read_lock(); pid = rcu_dereference(target->pid); if (pid) @@ -2319,13 +2354,19 @@ static bool kvm_vcpu_eligible_for_directed_yield(struct kvm_vcpu *vcpu) void kvm_vcpu_on_spin(struct kvm_vcpu *me) { - struct kvm *kvm = me->kvm; + struct kvm *kvm; struct kvm_vcpu *vcpu; - int last_boosted_vcpu = me->kvm->last_boosted_vcpu; + int last_boosted_vcpu; int yielded = 0; int try = 3; int pass; int i; + if (me == NULL) + return; + kvm = me->kvm; + if (kvm == NULL) + return; + last_boosted_vcpu = me->kvm->last_boosted_vcpu; kvm_vcpu_set_in_spin_loop(me, true); /* @@ -3542,6 +3583,8 @@ static int __kvm_io_bus_read(struct kvm_vcpu *vcpu, struct kvm_io_bus *bus, struct kvm_io_range *range, void *val) { int idx; + if (range == NULL) + return -EINVAL; idx = kvm_io_bus_get_first_dev(bus, range->addr, range->len); if (idx < 0) @@ -3653,6 +3696,9 @@ struct kvm_io_device *kvm_io_bus_get_dev(struct kvm *kvm, enum kvm_bus bus_idx, int dev_idx, srcu_idx; struct kvm_io_device *iodev = NULL; + if (kvm == NULL) + return NULL; + srcu_idx = srcu_read_lock(&kvm->srcu); bus = srcu_dereference(kvm->buses[bus_idx], &kvm->srcu); -- 2.11.0.1