path: root/include/linux/netfilter/nfnetlink.h
diff options
authorPablo Neira Ayuso <pablo@netfilter.org>2020-01-21 16:48:03 +0100
committerPablo Neira Ayuso <pablo@netfilter.org>2020-01-24 20:54:29 +0100
commiteb014de4fd418de1a277913cba244e47274fe392 (patch)
tree28f951dc135f9ff7d7363d314590582069792abe /include/linux/netfilter/nfnetlink.h
parentnetfilter: nf_tables: add __nft_chain_type_get() (diff)
netfilter: nf_tables: autoload modules from the abort path
This patch introduces a list of pending module requests. This new module list is composed of nft_module_request objects that contain the module name and one status field that tells if the module has been already loaded (the 'done' field). In the first pass, from the preparation phase, the netlink command finds that a module is missing on this list. Then, a module request is allocated and added to this list and nft_request_module() returns -EAGAIN. This triggers the abort path with the autoload parameter set on from nfnetlink, request_module() is called and the module request enters the 'done' state. Since the mutex is released when loading modules from the abort phase, the module list is zapped so this is iteration occurs over a local list. Therefore, the request_module() calls happen when object lists are in consistent state (after fulling aborting the transaction) and the commit list is empty. On the second pass, the netlink command will find that it already tried to load the module, so it does not request it again and nft_request_module() returns 0. Then, there is a look up to find the object that the command was missing. If the module was successfully loaded, the command proceeds normally since it finds the missing object in place, otherwise -ENOENT is reported to userspace. This patch also updates nfnetlink to include the reason to enter the abort phase, which is required for this new autoload module rationale. Fixes: ec7470b834fe ("netfilter: nf_tables: store transaction list locally while requesting module") Reported-by: syzbot+29125d208b3dae9a7019@syzkaller.appspotmail.com Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'include/linux/netfilter/nfnetlink.h')
1 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/netfilter/nfnetlink.h b/include/linux/netfilter/nfnetlink.h
index cf09ab37b45b..851425c3178f 100644
--- a/include/linux/netfilter/nfnetlink.h
+++ b/include/linux/netfilter/nfnetlink.h
@@ -31,7 +31,7 @@ struct nfnetlink_subsystem {
const struct nfnl_callback *cb; /* callback for individual types */
struct module *owner;
int (*commit)(struct net *net, struct sk_buff *skb);
- int (*abort)(struct net *net, struct sk_buff *skb);
+ int (*abort)(struct net *net, struct sk_buff *skb, bool autoload);
void (*cleanup)(struct net *net);
bool (*valid_genid)(struct net *net, u32 genid);