From: Gleb Natapov <gleb@redhat.com>
To: kvm@vger.kernel.org
Cc: pbonzini@redhat.com
Subject: [PATCH] Fix NULL dereference in gfn_to_hva_prot()
Date: Tue, 1 Oct 2013 19:58:36 +0300 [thread overview]
Message-ID: <20131001165836.GX11993@redhat.com> (raw)
gfn_to_memslot() can return NULL or invalid slot. We need to check slot
validity before accessing it.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 979bff4..a9dd682 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1064,10 +1064,12 @@ EXPORT_SYMBOL_GPL(gfn_to_hva);
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)
--
Gleb.
next reply other threads:[~2013-10-01 16:58 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-01 16:58 Gleb Natapov [this message]
2013-10-01 17:03 ` [PATCH] Fix NULL dereference in gfn_to_hva_prot() Paolo Bonzini
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