From 61f9e2924f4981d626b3a931fed935f2fa3cb4de Mon Sep 17 00:00:00 2001 From: Liping Zhang Date: Sat, 22 Oct 2016 18:51:25 +0800 Subject: [PATCH] netfilter: nf_tables: fix *leak* when expr clone fail When nft_expr_clone failed, a series of problems will happen: 1. module refcnt will leak, we call __module_get at the beginning but we forget to put it back if ops->clone returns fail 2. memory will be leaked, if clone fail, we just return NULL and forget to free the alloced element 3. set->nelems will become incorrect when set->size is specified. If clone fail, we should decrease the set->nelems Now this patch fixes these problems. And fortunately, clone fail will only happen on counter expression when memory is exhausted. Fixes: 086f332167d6 ("netfilter: nf_tables: add clone interface to expression operations") Signed-off-by: Liping Zhang Signed-off-by: Pablo Neira Ayuso --- include/net/netfilter/nf_tables.h | 6 ++++-- net/netfilter/nf_tables_api.c | 11 ++++++----- net/netfilter/nft_dynset.c | 16 ++++++++++------ net/netfilter/nft_set_hash.c | 4 ++-- net/netfilter/nft_set_rbtree.c | 2 +- 5 files changed, 23 insertions(+), 16 deletions(-) diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h index 5031e072567b..741dcded5b4f 100644 --- a/include/net/netfilter/nf_tables.h +++ b/include/net/netfilter/nf_tables.h @@ -542,7 +542,8 @@ void *nft_set_elem_init(const struct nft_set *set, const struct nft_set_ext_tmpl *tmpl, const u32 *key, const u32 *data, u64 timeout, gfp_t gfp); -void nft_set_elem_destroy(const struct nft_set *set, void *elem); +void nft_set_elem_destroy(const struct nft_set *set, void *elem, + bool destroy_expr); /** * struct nft_set_gc_batch_head - nf_tables set garbage collection batch @@ -693,7 +694,6 @@ static inline int nft_expr_clone(struct nft_expr *dst, struct nft_expr *src) { int err; - __module_get(src->ops->type->owner); if (src->ops->clone) { dst->ops = src->ops; err = src->ops->clone(dst, src); @@ -702,6 +702,8 @@ static inline int nft_expr_clone(struct nft_expr *dst, struct nft_expr *src) } else { memcpy(dst, src, src->ops->size); } + + __module_get(src->ops->type->owner); return 0; } diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 24db22257586..86e48aeb20be 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -3452,14 +3452,15 @@ void *nft_set_elem_init(const struct nft_set *set, return elem; } -void nft_set_elem_destroy(const struct nft_set *set, void *elem) +void nft_set_elem_destroy(const struct nft_set *set, void *elem, + bool destroy_expr) { struct nft_set_ext *ext = nft_set_elem_ext(set, elem); nft_data_uninit(nft_set_ext_key(ext), NFT_DATA_VALUE); if (nft_set_ext_exists(ext, NFT_SET_EXT_DATA)) nft_data_uninit(nft_set_ext_data(ext), set->dtype); - if (nft_set_ext_exists(ext, NFT_SET_EXT_EXPR)) + if (destroy_expr && nft_set_ext_exists(ext, NFT_SET_EXT_EXPR)) nf_tables_expr_destroy(NULL, nft_set_ext_expr(ext)); kfree(elem); @@ -3812,7 +3813,7 @@ void nft_set_gc_batch_release(struct rcu_head *rcu) gcb = container_of(rcu, struct nft_set_gc_batch, head.rcu); for (i = 0; i < gcb->head.cnt; i++) - nft_set_elem_destroy(gcb->head.set, gcb->elems[i]); + nft_set_elem_destroy(gcb->head.set, gcb->elems[i], true); kfree(gcb); } EXPORT_SYMBOL_GPL(nft_set_gc_batch_release); @@ -4030,7 +4031,7 @@ static void nf_tables_commit_release(struct nft_trans *trans) break; case NFT_MSG_DELSETELEM: nft_set_elem_destroy(nft_trans_elem_set(trans), - nft_trans_elem(trans).priv); + nft_trans_elem(trans).priv, true); break; } kfree(trans); @@ -4171,7 +4172,7 @@ static void nf_tables_abort_release(struct nft_trans *trans) break; case NFT_MSG_NEWSETELEM: nft_set_elem_destroy(nft_trans_elem_set(trans), - nft_trans_elem(trans).priv); + nft_trans_elem(trans).priv, true); break; } kfree(trans); diff --git a/net/netfilter/nft_dynset.c b/net/netfilter/nft_dynset.c index bfdb689664b0..31ca94793aa9 100644 --- a/net/netfilter/nft_dynset.c +++ b/net/netfilter/nft_dynset.c @@ -44,18 +44,22 @@ static void *nft_dynset_new(struct nft_set *set, const struct nft_expr *expr, ®s->data[priv->sreg_key], ®s->data[priv->sreg_data], timeout, GFP_ATOMIC); - if (elem == NULL) { - if (set->size) - atomic_dec(&set->nelems); - return NULL; - } + if (elem == NULL) + goto err1; ext = nft_set_elem_ext(set, elem); if (priv->expr != NULL && nft_expr_clone(nft_set_ext_expr(ext), priv->expr) < 0) - return NULL; + goto err2; return elem; + +err2: + nft_set_elem_destroy(set, elem, false); +err1: + if (set->size) + atomic_dec(&set->nelems); + return NULL; } static void nft_dynset_eval(const struct nft_expr *expr, diff --git a/net/netfilter/nft_set_hash.c b/net/netfilter/nft_set_hash.c index 3794cb2fc788..88d9fc8343e7 100644 --- a/net/netfilter/nft_set_hash.c +++ b/net/netfilter/nft_set_hash.c @@ -120,7 +120,7 @@ out: return true; err2: - nft_set_elem_destroy(set, he); + nft_set_elem_destroy(set, he, true); err1: return false; } @@ -332,7 +332,7 @@ static int nft_hash_init(const struct nft_set *set, static void nft_hash_elem_destroy(void *ptr, void *arg) { - nft_set_elem_destroy((const struct nft_set *)arg, ptr); + nft_set_elem_destroy((const struct nft_set *)arg, ptr, true); } static void nft_hash_destroy(const struct nft_set *set) diff --git a/net/netfilter/nft_set_rbtree.c b/net/netfilter/nft_set_rbtree.c index 38b5bda242f8..36493a7cae88 100644 --- a/net/netfilter/nft_set_rbtree.c +++ b/net/netfilter/nft_set_rbtree.c @@ -266,7 +266,7 @@ static void nft_rbtree_destroy(const struct nft_set *set) while ((node = priv->root.rb_node) != NULL) { rb_erase(node, &priv->root); rbe = rb_entry(node, struct nft_rbtree_elem, node); - nft_set_elem_destroy(set, rbe); + nft_set_elem_destroy(set, rbe, true); } }