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| author | Florian Westphal <fw@strlen.de> | 2022-02-21 15:31:49 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-03-02 13:41:09 +0300 |
| commit | 53026346a94c43f35c32b18804041bc483271d87 (patch) | |
| tree | 4bcfa116a34565a8ef16166c2325e0b594366c4a /net | |
| parent | 5ad5886f85b6bd893e3ed19013765fb0c243c069 (diff) | |
| download | linux-53026346a94c43f35c32b18804041bc483271d87.tar.xz | |
netfilter: nf_tables: fix memory leak during stateful obj update
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>
Diffstat (limited to 'net')
| -rw-r--r-- | net/netfilter/nf_tables_api.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 373ea0e49f12..545da270e802 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -5184,12 +5184,15 @@ 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)) { @@ -5206,6 +5209,8 @@ static int nf_tables_updobj(const struct nft_ctx *ctx, err_free_trans: kfree(trans); +err_trans: + module_put(type->owner); return err; } @@ -6544,7 +6549,7 @@ 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) @@ -7109,7 +7114,7 @@ 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--; |