From: Florian Westphal fw@strlen.de
commit dad3bdeef45f81a6e90204bcc85360bb76eccec7 upstream.
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@riseup.net Signed-off-by: Florian Westphal fw@strlen.de Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/netfilter/nf_tables_api.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-)
--- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -6535,12 +6535,15 @@ static int nf_tables_updobj(const struct { 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)) { @@ -6557,6 +6560,8 @@ static int nf_tables_updobj(const struct
err_free_trans: kfree(trans); +err_trans: + module_put(type->owner); return err; }
@@ -8169,7 +8174,7 @@ static void nft_obj_commit_update(struct 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) @@ -8914,7 +8919,7 @@ static int __nf_tables_abort(struct net 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--;