diff options
| author | Eric Dumazet <edumazet@google.com> | 2024-02-09 19:12:48 +0100 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2024-02-13 02:38:52 +0100 |
| commit | 9f30831390ede02d9fcd54fd9ea5a585ab649f4a (patch) | |
| tree | 70b567aaec747d3817da0e850aacc8967d2e9ae8 /net | |
| parent | pds_core: no health-thread in VF path (diff) | |
| download | linux-9f30831390ede02d9fcd54fd9ea5a585ab649f4a.tar.xz linux-9f30831390ede02d9fcd54fd9ea5a585ab649f4a.zip | |
net: add rcu safety to rtnl_prop_list_size()
rtnl_prop_list_size() can be called while alternative names
are added or removed concurrently.
if_nlmsg_size() / rtnl_calcit() can indeed be called
without RTNL held.
Use explicit RCU protection to avoid UAF.
Fixes: 88f4fb0c7496 ("net: rtnetlink: put alternative names to getlink message")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/20240209181248.96637-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/core/dev.c | 2 | ||||
| -rw-r--r-- | net/core/rtnetlink.c | 15 |
2 files changed, 10 insertions, 7 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index 9bb792cecc16..73a021973007 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -336,7 +336,7 @@ int netdev_name_node_alt_create(struct net_device *dev, const char *name) return -ENOMEM; netdev_name_node_add(net, name_node); /* The node that holds dev->name acts as a head of per-device list. */ - list_add_tail(&name_node->list, &dev->name_node->list); + list_add_tail_rcu(&name_node->list, &dev->name_node->list); return 0; } diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index f6f29eb03ec2..9c4f427f3a50 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -1020,14 +1020,17 @@ static size_t rtnl_xdp_size(void) static size_t rtnl_prop_list_size(const struct net_device *dev) { struct netdev_name_node *name_node; - size_t size; + unsigned int cnt = 0; + + rcu_read_lock(); + list_for_each_entry_rcu(name_node, &dev->name_node->list, list) + cnt++; + rcu_read_unlock(); - if (list_empty(&dev->name_node->list)) + if (!cnt) return 0; - size = nla_total_size(0); - list_for_each_entry(name_node, &dev->name_node->list, list) - size += nla_total_size(ALTIFNAMSIZ); - return size; + + return nla_total_size(0) + cnt * nla_total_size(ALTIFNAMSIZ); } static size_t rtnl_proto_down_size(const struct net_device *dev) |