From 6d07a289504a246aa97cdac0fec61a15834801b7 Mon Sep 17 00:00:00 2001 From: Phil Sutter Date: Wed, 21 May 2025 22:44:32 +0200 Subject: [PATCH] netfilter: nf_tables: Support wildcard netdev hook specs User space may pass non-nul-terminated NFTA_DEVICE_NAME attribute values to indicate a suffix wildcard. Expect for multiple devices to match the given prefix in nft_netdev_hook_alloc() and populate 'ops_list' with them all. When checking for duplicate hooks, compare the shortest prefix so a device may never match more than a single hook spec. Finally respect the stored prefix length when hooking into new devices from event handlers. Signed-off-by: Phil Sutter Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_tables_api.c | 29 ++++++++++++++--------------- net/netfilter/nft_chain_filter.c | 2 +- 2 files changed, 15 insertions(+), 16 deletions(-) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index fabc82c98871..a7240736f98e 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -2330,24 +2330,22 @@ static struct nft_hook *nft_netdev_hook_alloc(struct net *net, * indirectly serializing all the other holders of the commit_mutex with * the rtnl_mutex. */ - dev = __dev_get_by_name(net, hook->ifname); - if (!dev) { - err = -ENOENT; - goto err_hook_free; - } + for_each_netdev(net, dev) { + if (strncmp(dev->name, hook->ifname, hook->ifnamelen)) + continue; - ops = kzalloc(sizeof(struct nf_hook_ops), GFP_KERNEL_ACCOUNT); - if (!ops) { - err = -ENOMEM; - goto err_hook_free; + ops = kzalloc(sizeof(struct nf_hook_ops), GFP_KERNEL_ACCOUNT); + if (!ops) { + err = -ENOMEM; + goto err_hook_free; + } + ops->dev = dev; + list_add_tail(&ops->list, &hook->ops_list); } - ops->dev = dev; - list_add_tail(&ops->list, &hook->ops_list); - return hook; err_hook_free: - kfree(hook); + nft_netdev_hook_free(hook); return ERR_PTR(err); } @@ -2357,7 +2355,8 @@ static struct nft_hook *nft_hook_list_find(struct list_head *hook_list, struct nft_hook *hook; list_for_each_entry(hook, hook_list, list) { - if (!strcmp(hook->ifname, this->ifname)) + if (!strncmp(hook->ifname, this->ifname, + min(hook->ifnamelen, this->ifnamelen))) return hook; } @@ -9696,7 +9695,7 @@ static int nft_flowtable_event(unsigned long event, struct net_device *dev, list_for_each_entry(hook, &flowtable->hook_list, list) { ops = nft_hook_find_ops(hook, dev); - match = !strcmp(hook->ifname, dev->name); + match = !strncmp(hook->ifname, dev->name, hook->ifnamelen); switch (event) { case NETDEV_UNREGISTER: diff --git a/net/netfilter/nft_chain_filter.c b/net/netfilter/nft_chain_filter.c index b59f8be6370e..b16185e9a6dd 100644 --- a/net/netfilter/nft_chain_filter.c +++ b/net/netfilter/nft_chain_filter.c @@ -328,7 +328,7 @@ static int nft_netdev_event(unsigned long event, struct net_device *dev, list_for_each_entry(hook, &basechain->hook_list, list) { ops = nft_hook_find_ops(hook, dev); - match = !strcmp(hook->ifname, dev->name); + match = !strncmp(hook->ifname, dev->name, hook->ifnamelen); switch (event) { case NETDEV_UNREGISTER: -- 2.25.1