From: Antoine Tenart atenart@kernel.org
[ Upstream commit 4ae2bb81649dc03dfc95875f02126b14b773f7ab ]
Accesses to dev->xps_rxqs_map (when using dev->num_tc) should be protected by the rtnl lock, like we do for netif_set_xps_queue. I didn't see an actual bug being triggered, but let's be safe here and take the rtnl lock while accessing the map in sysfs.
Fixes: 8af2c06ff4b1 ("net-sysfs: Add interface for Rx queue(s) map per Tx queue") Signed-off-by: Antoine Tenart atenart@kernel.org Reviewed-by: Alexander Duyck alexanderduyck@fb.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/core/net-sysfs.c | 23 ++++++++++++++++++----- 1 file changed, 18 insertions(+), 5 deletions(-)
--- a/net/core/net-sysfs.c +++ b/net/core/net-sysfs.c @@ -1356,23 +1356,30 @@ static struct netdev_queue_attribute xps
static ssize_t xps_rxqs_show(struct netdev_queue *queue, char *buf) { + int j, len, ret, num_tc = 1, tc = 0; struct net_device *dev = queue->dev; struct xps_dev_maps *dev_maps; unsigned long *mask, index; - int j, len, num_tc = 1, tc = 0;
index = get_netdev_queue_index(queue);
+ if (!rtnl_trylock()) + return restart_syscall(); + if (dev->num_tc) { num_tc = dev->num_tc; tc = netdev_txq_to_tc(dev, index); - if (tc < 0) - return -EINVAL; + if (tc < 0) { + ret = -EINVAL; + goto err_rtnl_unlock; + } } mask = kcalloc(BITS_TO_LONGS(dev->num_rx_queues), sizeof(long), GFP_KERNEL); - if (!mask) - return -ENOMEM; + if (!mask) { + ret = -ENOMEM; + goto err_rtnl_unlock; + }
rcu_read_lock(); dev_maps = rcu_dereference(dev->xps_rxqs_map); @@ -1398,10 +1405,16 @@ static ssize_t xps_rxqs_show(struct netd out_no_maps: rcu_read_unlock();
+ rtnl_unlock(); + len = bitmap_print_to_pagebuf(false, buf, mask, dev->num_rx_queues); kfree(mask);
return len < PAGE_SIZE ? len : -EINVAL; + +err_rtnl_unlock: + rtnl_unlock(); + return ret; }
static ssize_t xps_rxqs_store(struct netdev_queue *queue, const char *buf,