genirq/affinity: Don't return with empty affinity masks on error

When the allocation of node_to_possible_cpumask fails, then
irq_create_affinity_masks() returns with a pointer to the empty affinity
masks array, which will cause malfunction.

Reorder the allocations so the masks array allocation comes last and every
failure path returns NULL.

Fixes: 9a0ef98e186d ("genirq/affinity: Assign vectors to all present CPUs")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Ming Lei <ming.lei@redhat.com>

1 files changed, 8 insertions, 7 deletions

diff --git a/kernel/irq/affinity.c b/kernel/irq/affinity.c
index a37a3b4b6342..e0665549af59 100644
--- a/kernel/irq/affinity.c
+++ b/kernel/irq/affinity.c
@@ -108,7 +108,7 @@ irq_create_affinity_masks(int nvecs, const struct irq_affinity *affd)
         int affv = nvecs - affd->pre_vectors - affd->post_vectors;
         int last_affv = affv + affd->pre_vectors;
         nodemask_t nodemsk = NODE_MASK_NONE;
-        struct cpumask *masks;
+        struct cpumask *masks = NULL;
         cpumask_var_t nmsk, *node_to_possible_cpumask;
 
         /*
@@ -121,13 +121,13 @@ irq_create_affinity_masks(int nvecs, const struct irq_affinity *affd)
         if (!zalloc_cpumask_var(&nmsk, GFP_KERNEL))
                 return NULL;
 
-        masks = kcalloc(nvecs, sizeof(*masks), GFP_KERNEL);
-        if (!masks)
-                goto out;
-
         node_to_possible_cpumask = alloc_node_to_possible_cpumask();
         if (!node_to_possible_cpumask)
-                goto out;
+                goto outcpumsk;
+
+        masks = kcalloc(nvecs, sizeof(*masks), GFP_KERNEL);
+        if (!masks)
+                goto outnodemsk;
 
         /* Fill out vectors at the beginning that don't need affinity */
         for (curvec = 0; curvec < affd->pre_vectors; curvec++)
@@ -192,8 +192,9 @@ done:
         /* Fill out vectors at the end that don't need affinity */
         for (; curvec < nvecs; curvec++)
                 cpumask_copy(masks + curvec, irq_default_affinity);
+outnodemsk:
         free_node_to_possible_cpumask(node_to_possible_cpumask);
-out:
+outcpumsk:
         free_cpumask_var(nmsk);
         return masks;
 }