We have several problems in this path: 1) There is a use-after-free when removing individual elements from the commit path. 2) We have to uninit() the data part of the element from the abort path to avoid a chain refcount leak. 3) We have to check for set->flags to see if there's a mapping, instead of the element flags. 4) We have to check for !(flags & NFT_SET_ELEM_INTERVAL_END) to skip elements that are part of the interval that have no data part, so they don't need to be uninit(). Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx> --- This fix replaces the following two patches: http://patchwork.ozlabs.org/patch/440781/ http://patchwork.ozlabs.org/patch/440782/ Thanks to Patrick for helping on discussing this fix! net/netfilter/nf_tables_api.c | 21 ++++++++++++--------- 1 file changed, 12 insertions(+), 9 deletions(-) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 199fd0f..a8c9462 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -3612,12 +3612,11 @@ static int nf_tables_commit(struct sk_buff *skb) &te->elem, NFT_MSG_DELSETELEM, 0); te->set->ops->get(te->set, &te->elem); - te->set->ops->remove(te->set, &te->elem); nft_data_uninit(&te->elem.key, NFT_DATA_VALUE); - if (te->elem.flags & NFT_SET_MAP) { - nft_data_uninit(&te->elem.data, - te->set->dtype); - } + if (te->set->flags & NFT_SET_MAP && + !(te->elem.flags & NFT_SET_ELEM_INTERVAL_END)) + nft_data_uninit(&te->elem.data, te->set->dtype); + te->set->ops->remove(te->set, &te->elem); nft_trans_destroy(trans); break; } @@ -3658,7 +3657,7 @@ static int nf_tables_abort(struct sk_buff *skb) { struct net *net = sock_net(skb->sk); struct nft_trans *trans, *next; - struct nft_set *set; + struct nft_trans_elem *te; list_for_each_entry_safe(trans, next, &net->nft.commit_list, list) { switch (trans->msg_type) { @@ -3719,9 +3718,13 @@ static int nf_tables_abort(struct sk_buff *skb) break; case NFT_MSG_NEWSETELEM: nft_trans_elem_set(trans)->nelems--; - set = nft_trans_elem_set(trans); - set->ops->get(set, &nft_trans_elem(trans)); - set->ops->remove(set, &nft_trans_elem(trans)); + te = (struct nft_trans_elem *)trans->data; + te->set->ops->get(te->set, &te->elem); + nft_data_uninit(&te->elem.key, NFT_DATA_VALUE); + if (te->set->flags & NFT_SET_MAP && + !(te->elem.flags & NFT_SET_ELEM_INTERVAL_END)) + nft_data_uninit(&te->elem.data, te->set->dtype); + te->set->ops->remove(te->set, &te->elem); nft_trans_destroy(trans); break; case NFT_MSG_DELSETELEM: -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
