[net PATCH] net-sysfs: Fix memory leak in XPS configuration

[net PATCH] net-sysfs: Fix memory leak in XPS configuration

[Alexander Duyck]

This patch reorders the error cases in showing the XPS configuration so
that we hold off on memory allocation until after we have verified that we
can support XPS on a given ring.

Fixes: 184c449f91fe ("net: Add support for XPS with QoS via traffic classes")
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
---
 net/core/net-sysfs.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index c476f07..bb7e80f 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -1214,9 +1214,6 @@ static ssize_t xps_cpus_show(struct netdev_queue *queue,
 	cpumask_var_t mask;
 	unsigned long index;
 
-	if (!zalloc_cpumask_var(&mask, GFP_KERNEL))
-		return -ENOMEM;
-
 	index = get_netdev_queue_index(queue);
 
 	if (dev->num_tc) {
@@ -1226,6 +1223,9 @@ static ssize_t xps_cpus_show(struct netdev_queue *queue,
 			return -EINVAL;
 	}
 
+	if (!zalloc_cpumask_var(&mask, GFP_KERNEL))
+		return -ENOMEM;
+
 	rcu_read_lock();
 	dev_maps = rcu_dereference(dev->xps_maps);
 	if (dev_maps) {

Re: [net PATCH] net-sysfs: Fix memory leak in XPS configuration

[David Miller]

From: Alexander Duyck <alexander.h.duyck@intel.com>
Date: Thu, 31 May 2018 15:59:46 -0400

> This patch reorders the error cases in showing the XPS configuration so
> that we hold off on memory allocation until after we have verified that we
> can support XPS on a given ring.
> 
> Fixes: 184c449f91fe ("net: Add support for XPS with QoS via traffic classes")
> Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>

Applied and queued up for -stable.