KVM: fix irq_source_id size verification

commit cd5a2685de4a642fd0bd763e8c19711ef08dbe27 upstream.

find_first_zero_bit works with bit numbers, not bytes.

Fixes

https://sourceforge.net/tracker/?func=detail&aid=2847560&group_id=180599&atid=893831

Reported-by: "Xu, Jiajun" <jiajun.xu@intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/virt/kvm/irq_comm.c b/virt/kvm/irq_comm.c
index 001663ff401a42ca5de902eb72ed13cf03b63218..03e5b217e88b9f640e9c3c3c4b1b50a96303b6f4 100644 (file)
--- a/virt/kvm/irq_comm.c
+++ b/virt/kvm/irq_comm.c
@@ -205,10 +205,9 @@ int kvm_request_irq_source_id(struct kvm *kvm)
        int irq_source_id;
 
        mutex_lock(&kvm->irq_lock);
-       irq_source_id = find_first_zero_bit(bitmap,
-                               sizeof(kvm->arch.irq_sources_bitmap));
+       irq_source_id = find_first_zero_bit(bitmap, BITS_PER_LONG);
 
-       if (irq_source_id >= sizeof(kvm->arch.irq_sources_bitmap)) {
+       if (irq_source_id >= BITS_PER_LONG) {
                printk(KERN_WARNING "kvm: exhaust allocatable IRQ sources!\n");
                return -EFAULT;
        }
@@ -228,7 +227,7 @@ void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
 
        mutex_lock(&kvm->irq_lock);
        if (irq_source_id < 0 ||
-           irq_source_id >= sizeof(kvm->arch.irq_sources_bitmap)) {
+           irq_source_id >= BITS_PER_LONG) {
                printk(KERN_ERR "kvm: IRQ source ID out of range!\n");
                return;
        }