aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorHaimin Zhang <tcs_kernel@tencent.com>2021-09-03 10:37:06 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-10-07 07:53:19 +0200
commit4664318f73e496cd22c71b10888e75434a123e23 (patch)
tree86046b1eb99dc117503b82c2246dad50fa1a797f
parent38c84dfafed5b1193d083e0121ccd985ce5f5bdc (diff)
downloadlinux-yocto-4664318f73e496cd22c71b10888e75434a123e23.tar.gz
linux-yocto-4664318f73e496cd22c71b10888e75434a123e23.tar.bz2
linux-yocto-4664318f73e496cd22c71b10888e75434a123e23.zip
KVM: x86: Handle SRCU initialization failure during page track init
commit eb7511bf9182292ef1df1082d23039e856d1ddfb upstream. Check the return of init_srcu_struct(), which can fail due to OOM, when initializing the page track mechanism. Lack of checking leads to a NULL pointer deref found by a modified syzkaller. Reported-by: TCS Robot <tcs_robot@tencent.com> Signed-off-by: Haimin Zhang <tcs_kernel@tencent.com> Message-Id: <1630636626-12262-1-git-send-email-tcs_kernel@tencent.com> [Move the call towards the beginning of kvm_arch_init_vm. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--arch/x86/include/asm/kvm_page_track.h2
-rw-r--r--arch/x86/kvm/mmu/page_track.c4
-rw-r--r--arch/x86/kvm/x86.c7
3 files changed, 9 insertions, 4 deletions
diff --git a/arch/x86/include/asm/kvm_page_track.h b/arch/x86/include/asm/kvm_page_track.h
index 87bd6025d91d..6a5f3acf2b33 100644
--- a/arch/x86/include/asm/kvm_page_track.h
+++ b/arch/x86/include/asm/kvm_page_track.h
@@ -46,7 +46,7 @@ struct kvm_page_track_notifier_node {
struct kvm_page_track_notifier_node *node);
};
-void kvm_page_track_init(struct kvm *kvm);
+int kvm_page_track_init(struct kvm *kvm);
void kvm_page_track_cleanup(struct kvm *kvm);
void kvm_page_track_free_memslot(struct kvm_memory_slot *slot);
diff --git a/arch/x86/kvm/mmu/page_track.c b/arch/x86/kvm/mmu/page_track.c
index 91a9f7e0fd91..68e67228101d 100644
--- a/arch/x86/kvm/mmu/page_track.c
+++ b/arch/x86/kvm/mmu/page_track.c
@@ -163,13 +163,13 @@ void kvm_page_track_cleanup(struct kvm *kvm)
cleanup_srcu_struct(&head->track_srcu);
}
-void kvm_page_track_init(struct kvm *kvm)
+int kvm_page_track_init(struct kvm *kvm)
{
struct kvm_page_track_notifier_head *head;
head = &kvm->arch.track_notifier_head;
- init_srcu_struct(&head->track_srcu);
INIT_HLIST_HEAD(&head->track_notifier_list);
+ return init_srcu_struct(&head->track_srcu);
}
/*
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 09e01a76ab0d..6d5d6e93f5c4 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -11093,9 +11093,15 @@ void kvm_arch_free_vm(struct kvm *kvm)
int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
{
+ int ret;
+
if (type)
return -EINVAL;
+ ret = kvm_page_track_init(kvm);
+ if (ret)
+ return ret;
+
INIT_HLIST_HEAD(&kvm->arch.mask_notifier_list);
INIT_LIST_HEAD(&kvm->arch.active_mmu_pages);
INIT_LIST_HEAD(&kvm->arch.zapped_obsolete_pages);
@@ -11128,7 +11134,6 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
kvm_apicv_init(kvm);
kvm_hv_init_vm(kvm);
- kvm_page_track_init(kvm);
kvm_mmu_init_vm(kvm);
return static_call(kvm_x86_vm_init)(kvm);