No description
  • C 96.8%
  • Assembly 0.9%
  • Rust 0.7%
  • Shell 0.6%
  • Python 0.5%
  • Other 0.3%
Find a file
Fernando Fernandez Mancera 95d9748cc9 netfilter: nf_conncount: fix tracking of connections from localhost
[ Upstream commit de8a70cefc ]

Since commit be102eb6a0 ("netfilter: nf_conncount: rework API to use
sk_buff directly"), we skip the adding and trigger a GC when the ct is
confirmed. For connections originated from local to local it doesn't
work because the connection is confirmed on POSTROUTING, therefore
tracking on the INPUT hook is always skipped.

In order to fix this, we check whether skb input ifindex is set to
loopback ifindex. If it is then we fallback on a GC plus track operation
skipping the optimization. This fallback is necessary to avoid
duplicated tracking of a packet train e.g 10 UDP datagrams sent on a
burst when initiating the connection.

Tested with xt_connlimit/nft_connlimit and OVS limit and with a HTTP
server and iperf3 on UDP mode.

Fixes: be102eb6a0 ("netfilter: nf_conncount: rework API to use sk_buff directly")
Reported-by: Michal Slabihoudek <michal.slabihoudek@gooddata.com>
Closes: https://lore.kernel.org/netfilter/6989BD9F-8C24-4397-9AD7-4613B28BF0DB@gooddata.com/
Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
History 2026-03-04 07:20:02 -05:00
arch
block
certs
crypto
Documentation
drivers
fs
include
init
io_uring
ipc
kernel
lib
LICENSES
mm
net
rust
samples
scripts
security
sound
tools
usr
virt
.clang-format
.clippy.toml
.cocciconfig
.editorconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
.rustfmt.toml
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS
Makefile
README

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

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.

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.