tree c56c46d3886e47a13d39a505733ac46eb44c36fe
parent f68a45776a62fce560e4e28f89c5009895066ae1
author Pablo Neira Ayuso <pablo@netfilter.org> 1485215492 +0100
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1497674517 +0200

netfilter: nf_tables: fix set->nelems counting with no NLM_F_EXCL


[ Upstream commit 35d0ac9070ef619e3bf44324375878a1c540387b ]

If the element exists and no NLM_F_EXCL is specified, do not bump
set->nelems, otherwise we leak one set element slot. This problem
amplifies if the set is full since the abort path always decrements the
counter for the -ENFILE case too, giving one spare extra slot.

Fix this by moving set->nelems update to nft_add_set_elem() after
successful element insertion. Moreover, remove the element if the set is
full so there is no need to rely on the abort path to undo things
anymore.

Fixes: c016c7e45ddf ("netfilter: nf_tables: honor NLM_F_EXCL flag in set element insertion")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>