From: Florian Westphal <fw@xxxxxxxxx>
stateful objects can be updated from the control plane.
The transaction logic allocates a temporary object for this purpose.
The ->init function was called for this object, so plain kfree() leaks
resources. We must call ->destroy function of the object.
nft_obj_destroy does this, but it also decrements the module refcount,
but the update path doesn't increment it.
To avoid special-casing the update object release, do module_get for
the update case too and release it via nft_obj_destroy().
Fixes: d62d0ba97b58 ("netfilter: nf_tables: Introduce stateful object update operation")
Cc: Fernando Fernandez Mancera <ffmancera@xxxxxxxxxx>
Signed-off-by: Florian Westphal <fw@xxxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
net/netfilter/nf_tables_api.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 3081c4399f10..9cd1d7a62804 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -6551,12 +6551,15 @@ static int nf_tables_updobj(const struct nft_ctx *ctx,
{
struct nft_object *newobj;
struct nft_trans *trans;
- int err;
+ int err = -ENOMEM;
+
+ if (!try_module_get(type->owner))
+ return -ENOENT;
trans = nft_trans_alloc(ctx, NFT_MSG_NEWOBJ,
sizeof(struct nft_trans_obj));
if (!trans)
- return -ENOMEM;
+ goto err_trans;
newobj = nft_obj_init(ctx, type, attr);
if (IS_ERR(newobj)) {
@@ -6573,6 +6576,8 @@ static int nf_tables_updobj(const struct nft_ctx *ctx,
err_free_trans:
kfree(trans);
+err_trans:
+ module_put(type->owner);
return err;
}
@@ -8185,7 +8190,7 @@ static void nft_obj_commit_update(struct nft_trans *trans)
if (obj->ops->update)
obj->ops->update(obj, newobj);
- kfree(newobj);
+ nft_obj_destroy(&trans->ctx, newobj);
}
static void nft_commit_release(struct nft_trans *trans)
@@ -8976,7 +8981,7 @@ static int __nf_tables_abort(struct net *net, enum nfnl_abort_action action)
break;
case NFT_MSG_NEWOBJ:
if (nft_trans_obj_update(trans)) {
- kfree(nft_trans_obj_newobj(trans));
+ nft_obj_destroy(&trans->ctx, nft_trans_obj_newobj(trans));
nft_trans_destroy(trans);
} else {
trans->ctx.table->use--;
--
2.30.2
