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

commit 0211e12dd0a5385ecffd3557bc570dbad7fcf245 upstream.

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>
Cc: Mihai Carabas <mihai.carabas@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/kernel/irq/affinity.c b/kernel/irq/affinity.c
index a37a3b4..e066554 100644 (file)
--- 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;
 }