IB/hfi1: Fix memory leak in exception path in get_irq_affinity()

When IRQ affinity is set and the interrupt type is unknown, a cpu
mask allocated within the function is never freed. Fix this memory
leak by allocating memory within the scope where it is used.
Reviewed-by: NMike Marciniszyn <mike.marciniszyn@intel.com>
Reviewed-by: NMichael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: NSebastian Sanchez <sebastian.sanchez@intel.com>
Signed-off-by: NDennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

drivers/infiniband/hw/hfi1/affinity.c

@@ -412,7 +412,6 @@ static void hfi1_cleanup_sdma_notifier(struct hfi1_msix_entry *msix)
 static int get_irq_affinity(struct hfi1_devdata *dd,
 			    struct hfi1_msix_entry *msix)
 {
-	int ret;
 	cpumask_var_t diff;
 	struct hfi1_affinity_node *entry;
 	struct cpu_mask_set *set = NULL;
@@ -424,10 +423,6 @@ static int get_irq_affinity(struct hfi1_devdata *dd,
 	extra[0] = '\0';
 	cpumask_clear(&msix->mask);
 
-	ret = zalloc_cpumask_var(&diff, GFP_KERNEL);
-	if (!ret)
-		return -ENOMEM;
-
 	entry = node_affinity_lookup(dd->node);
 
 	switch (msix->type) {
@@ -458,6 +453,9 @@ static int get_irq_affinity(struct hfi1_devdata *dd,
 	 * finds its CPU here.
 	 */
 	if (cpu == -1 && set) {
+		if (!zalloc_cpumask_var(&diff, GFP_KERNEL))
+			return -ENOMEM;
+
 		if (cpumask_equal(&set->mask, &set->used)) {
 			/*
 			 * We've used up all the CPUs, bump up the generation
@@ -469,6 +467,8 @@ static int get_irq_affinity(struct hfi1_devdata *dd,
 		cpumask_andnot(diff, &set->mask, &set->used);
 		cpu = cpumask_first(diff);
 		cpumask_set_cpu(cpu, &set->used);
+
+		free_cpumask_var(diff);
 	}
 
 	cpumask_set_cpu(cpu, &msix->mask);
@@ -482,7 +482,6 @@ static int get_irq_affinity(struct hfi1_devdata *dd,
 		hfi1_setup_sdma_notifier(msix);
 	}
 
-	free_cpumask_var(diff);
 	return 0;
 }