[PATCH 4.16 067/272] genirq/affinity: Dont return with empty affinity masks on error

Greg Kroah-Hartman
2018-05-28T11:07:07Z

From: Thomas Gleixner <tglx@linutronix.de>

[ Upstream commit 0211e12dd0a5385ecffd3557bc570dbad7fcf245 ]

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>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
kernel/irq/affinity.c | 15 ++++++++-------
1 file changed, 8 insertions(+), 7 deletions(-)

--- a/kernel/irq/affinity.c
+++ b/kernel/irq/affinity.c
@@ -108,7 +108,7 @@ irq_create_affinity_masks(int nvecs, con
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, con
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;
}