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authorJakub Kicinski <kuba@kernel.org>2024-01-19 03:58:59 +0300
committerDavid S. Miller <davem@davemloft.net>2024-01-22 04:09:30 +0300
commitd09486a04f5da0a812c26217213b89a3b1acf836 (patch)
treee567450ae2501328105b5ebfc530f0b8b62f44f1 /net
parent359724fa3ab79fbe9f42c6263cddc2afae32eef3 (diff)
downloadlinux-d09486a04f5da0a812c26217213b89a3b1acf836.tar.xz
net: fix removing a namespace with conflicting altnames
Mark reports a BUG() when a net namespace is removed. kernel BUG at net/core/dev.c:11520! Physical interfaces moved outside of init_net get "refunded" to init_net when that namespace disappears. The main interface name may get overwritten in the process if it would have conflicted. We need to also discard all conflicting altnames. Recent fixes addressed ensuring that altnames get moved with the main interface, which surfaced this problem. Reported-by: Марк Коренберг <socketpair@gmail.com> Link: https://lore.kernel.org/all/CAEmTpZFZ4Sv3KwqFOY2WKDHeZYdi0O7N5H1nTvcGp=SAEavtDg@mail.gmail.com/ Fixes: 7663d522099e ("net: check for altname conflicts when changing netdev's netns") Signed-off-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Reviewed-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/core/dev.c9
-rw-r--r--net/core/dev.h3
2 files changed, 12 insertions, 0 deletions
diff --git a/net/core/dev.c b/net/core/dev.c
index f01a9b858347..cb2dab0feee0 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -11551,6 +11551,7 @@ static struct pernet_operations __net_initdata netdev_net_ops = {
static void __net_exit default_device_exit_net(struct net *net)
{
+ struct netdev_name_node *name_node, *tmp;
struct net_device *dev, *aux;
/*
* Push all migratable network devices back to the
@@ -11573,6 +11574,14 @@ static void __net_exit default_device_exit_net(struct net *net)
snprintf(fb_name, IFNAMSIZ, "dev%d", dev->ifindex);
if (netdev_name_in_use(&init_net, fb_name))
snprintf(fb_name, IFNAMSIZ, "dev%%d");
+
+ netdev_for_each_altname_safe(dev, name_node, tmp)
+ if (netdev_name_in_use(&init_net, name_node->name)) {
+ netdev_name_node_del(name_node);
+ synchronize_rcu();
+ __netdev_name_node_alt_destroy(name_node);
+ }
+
err = dev_change_net_namespace(dev, &init_net, fb_name);
if (err) {
pr_emerg("%s: failed to move %s to init_net: %d\n",
diff --git a/net/core/dev.h b/net/core/dev.h
index cf93e188785b..7480b4c84298 100644
--- a/net/core/dev.h
+++ b/net/core/dev.h
@@ -63,6 +63,9 @@ int dev_change_name(struct net_device *dev, const char *newname);
#define netdev_for_each_altname(dev, namenode) \
list_for_each_entry((namenode), &(dev)->name_node->list, list)
+#define netdev_for_each_altname_safe(dev, namenode, next) \
+ list_for_each_entry_safe((namenode), (next), &(dev)->name_node->list, \
+ list)
int netdev_name_node_alt_create(struct net_device *dev, const char *name);
int netdev_name_node_alt_destroy(struct net_device *dev, const char *name);