[PATCH v3 1/6] KVM: fix missing check for memslot flags

[Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>]

Check flags when memslot is registered from userspace as Avi's suggestion

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
---
 virt/kvm/kvm_main.c |   12 ++++++++++++
 1 files changed, 12 insertions(+), 0 deletions(-)

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 02cb440..6a7756c 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -686,6 +686,14 @@ void update_memslots(struct kvm_memslots *slots, struct kvm_memory_slot *new)
 	slots->generation++;
 }

+static int check_memory_region_flags(struct kvm_userspace_memory_region *mem)
+{
+	if (mem->flags & ~KVM_MEM_LOG_DIRTY_PAGES)
+		return -EINVAL;
+
+	return 0;
+}
+
 /*
  * Allocate some memory and give it an address in the guest physical address
  * space.
@@ -706,6 +714,10 @@ int __kvm_set_memory_region(struct kvm *kvm,
 	struct kvm_memory_slot old, new;
 	struct kvm_memslots *slots, *old_memslots;

+	r = check_memory_region_flags(mem);
+	if (r)
+		goto out;
+
 	r = -EINVAL;
 	/* General sanity checks */
 	if (mem->memory_size & (PAGE_SIZE - 1))
-- 
1.7.7.6