Fix NULL dereference in gfn_to_hva_prot()
gfn_to_memslot() can return NULL or invalid slot. We need to check slot
validity before accessing it.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
(cherry picked from commit a2ac07fe292ea41296049dfdbfeed203e2467ee7)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 8b47fd2..c5bc5ae 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1065,10 +1065,12 @@
unsigned long gfn_to_hva_prot(struct kvm *kvm, gfn_t gfn, bool *writable)
{
struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn);
- if (writable)
+ unsigned long hva = __gfn_to_hva_many(slot, gfn, NULL, false);
+
+ if (!kvm_is_error_hva(hva) && writable)
*writable = !memslot_is_readonly(slot);
- return __gfn_to_hva_many(gfn_to_memslot(kvm, gfn), gfn, NULL, false);
+ return hva;
}
static int kvm_read_hva(void *data, void __user *hva, int len)