[PATCH 5.4 58/91] gtp: Use for_each_netdev_rcu() in gtp_genl_dump_pdp().

5.4-stable review patch. If anyone has any objections, please let me know.

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From: Kuniyuki Iwashima kuniyu@amazon.com

[ Upstream commit 46841c7053e6d25fb33e0534ef023833bf03e382 ]

gtp_newlink() links the gtp device to a list in dev_net(dev).

However, even after the gtp device is moved to another netns, it stays on the list but should be invisible.

Let's use for_each_netdev_rcu() for netdev traversal in gtp_genl_dump_pdp().

Note that gtp_dev_list is no longer used under RCU, so list helpers are converted to the non-RCU variant.

Fixes: 459aa660eb1d ("gtp: add initial driver for datapath of GPRS Tunneling Protocol (GTP-U)") Reported-by: Xiao Liang shaw.leon@gmail.com Closes: https://lore.kernel.org/netdev/CABAhCOQdBL6h9M2C+kd+bGivRJ9Q72JUxW+-gur0nub_... Signed-off-by: Kuniyuki Iwashima kuniyu@amazon.com Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/gtp.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c index fd5d3f58b5c10..e08cd4b1be6c1 100644 --- a/drivers/net/gtp.c +++ b/drivers/net/gtp.c @@ -691,7 +691,7 @@ static int gtp_newlink(struct net *src_net, struct net_device *dev, }

gn = net_generic(dev_net(dev), gtp_net_id); - list_add_rcu(&gtp->list, &gn->gtp_dev_list); + list_add(&gtp->list, &gn->gtp_dev_list); dev->priv_destructor = gtp_destructor;

netdev_dbg(dev, "registered new GTP interface\n"); @@ -717,7 +717,7 @@ static void gtp_dellink(struct net_device *dev, struct list_head *head) hlist_for_each_entry_safe(pctx, next, &gtp->tid_hash[i], hlist_tid) pdp_context_delete(pctx);

- list_del_rcu(&gtp->list); + list_del(&gtp->list); unregister_netdevice_queue(dev, head); }

@@ -1259,16 +1259,19 @@ static int gtp_genl_dump_pdp(struct sk_buff *skb, struct gtp_dev *last_gtp = (struct gtp_dev *)cb->args[2], *gtp; int i, j, bucket = cb->args[0], skip = cb->args[1]; struct net *net = sock_net(skb->sk); + struct net_device *dev; struct pdp_ctx *pctx; - struct gtp_net *gn; - - gn = net_generic(net, gtp_net_id);

if (cb->args[4]) return 0;

rcu_read_lock(); - list_for_each_entry_rcu(gtp, &gn->gtp_dev_list, list) { + for_each_netdev_rcu(net, dev) { + if (dev->rtnl_link_ops != &gtp_link_ops) + continue; + + gtp = netdev_priv(dev); + if (last_gtp && last_gtp != gtp) continue; else @@ -1362,9 +1365,9 @@ static void __net_exit gtp_net_exit_batch_rtnl(struct list_head *net_list,

list_for_each_entry(net, net_list, exit_list) { struct gtp_net *gn = net_generic(net, gtp_net_id); - struct gtp_dev *gtp; + struct gtp_dev *gtp, *gtp_next;

- list_for_each_entry(gtp, &gn->gtp_dev_list, list) + list_for_each_entry_safe(gtp, gtp_next, &gn->gtp_dev_list, list) gtp_dellink(gtp->dev, dev_to_kill); } }