Taehee Yoo 4c541a5aec netfilter: nf_tables: fix leaking object reference count
[ Upstream commit b91d903688 ]

There is no code that decreases the reference count of stateful objects
in error path of the nft_add_set_elem(). this causes a leak of reference
count of stateful objects.

Test commands:
   $nft add table ip filter
   $nft add counter ip filter c1
   $nft add map ip filter m1 { type ipv4_addr : counter \;}
   $nft add element ip filter m1 { 1 : c1 }
   $nft add element ip filter m1 { 1 : c1 }
   $nft delete element ip filter m1 { 1 }
   $nft delete counter ip filter c1

Result:
   Error: Could not process rule: Device or resource busy
   delete counter ip filter c1
   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^

At the second 'nft add element ip filter m1 { 1 : c1 }', the reference
count of the 'c1' is increased then it tries to insert into the 'm1'. but
the 'm1' already has same element so it returns -EEXIST.
But it doesn't decrease the reference count of the 'c1' in the error path.
Due to a leak of the reference count of the 'c1', the 'c1' can't be
removed by 'nft delete counter ip filter c1'.

Fixes: 8aeff920dc ("netfilter: nf_tables: add stateful object reference to set elements")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-02-27 10:08:04 +01:00
2019-02-20 10:20:44 +01:00
2019-02-23 09:06:44 +01:00

Linux kernel
============

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
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