[PATCH 11/11] KVM: fix vcpu freeing bug

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



From: Ingo Molnar <[email protected]>

vcpu_load() can return NULL and it sometimes does in failure paths (for 
example when the userspace ABI version is too old) - causing a 
preemption count underflow in the ->vcpu_free() later on. So check for 
NULL.

Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Avi Kivity <[email protected]>

Index: linux-2.6/drivers/kvm/kvm_main.c
===================================================================
--- linux-2.6.orig/drivers/kvm/kvm_main.c
+++ linux-2.6/drivers/kvm/kvm_main.c
@@ -272,7 +272,9 @@ static void kvm_free_physmem(struct kvm 
 
 static void kvm_free_vcpu(struct kvm_vcpu *vcpu)
 {
-	vcpu_load(vcpu->kvm, vcpu_slot(vcpu));
+	if (!vcpu_load(vcpu->kvm, vcpu_slot(vcpu)))
+		return;
+
 	kvm_mmu_destroy(vcpu);
 	vcpu_put(vcpu);
 	kvm_arch_ops->vcpu_free(vcpu);
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Stuff]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]     [Linux Resources]
  Powered by Linux