diff options
| author | Jakub Kicinski | 2023-10-17 18:38:15 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman | 2023-10-25 12:03:08 +0200 |
| commit | b92433493bcc81674851fd9869ba1d474fa6f032 (patch) | |
| tree | ac2538536a10b1d9f4e3004c1e94f59a8ec4f9dc /net/core | |
| parent | 1cf912054a08a548ff229fc6225a34e46bd02786 (diff) | |
net: avoid UAF on deleted altname
commit 1a83f4a7c156fa6bbd6b530e89fa3270bf3d9d1b upstream.
Altnames are accessed under RCU (dev_get_by_name_rcu())
but freed by kfree() with no synchronization point.
Each node has one or two allocations (node and a variable-size
name, sometimes the name is netdev->name). Adding rcu_heads
here is a bit tedious. Besides most code which unlists the names
already has rcu barriers - so take the simpler approach of adding
synchronize_rcu(). Note that the one on the unregistration path
(which matters more) is removed by the next fix.
Fixes: ff92741270bf ("net: introduce name_node struct to be used in hashlist")
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/core')
| -rw-r--r-- | net/core/dev.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index 5374761f5af2..a9777f33c6bf 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -345,7 +345,6 @@ int netdev_name_node_alt_create(struct net_device *dev, const char *name) static void __netdev_name_node_alt_destroy(struct netdev_name_node *name_node) { list_del(&name_node->list); - netdev_name_node_del(name_node); kfree(name_node->name); netdev_name_node_free(name_node); } @@ -364,6 +363,8 @@ int netdev_name_node_alt_destroy(struct net_device *dev, const char *name) if (name_node == dev->name_node || name_node->dev != dev) return -EINVAL; + netdev_name_node_del(name_node); + synchronize_rcu(); __netdev_name_node_alt_destroy(name_node); return 0; @@ -10835,6 +10836,7 @@ void unregister_netdevice_many(struct list_head *head) synchronize_net(); list_for_each_entry(dev, head, unreg_list) { + struct netdev_name_node *name_node; struct sk_buff *skb = NULL; /* Shutdown queueing discipline. */ @@ -10860,6 +10862,9 @@ void unregister_netdevice_many(struct list_head *head) dev_uc_flush(dev); dev_mc_flush(dev); + netdev_for_each_altname(dev, name_node) + netdev_name_node_del(name_node); + synchronize_rcu(); netdev_name_node_alt_flush(dev); netdev_name_node_free(dev->name_node); |