Linux kernel modifications for the Kernel Hacking exam
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Florian Westphal a4e6a1031e netfilter: conntrack: add clash resolution for reverse collisions
Given existing entry:
ORIGIN: a:b -> c:d
REPLY:  c:d -> a:b

And colliding entry:
ORIGIN: c:d -> a:b
REPLY:  a:b -> c:d

The colliding ct (and the associated skb) get dropped on insert.
Permit this by checking if the colliding entry matches the reply
direction.

Happens when both ends send packets at same time, both requests are picked
up as NEW, rather than NEW for the 'first' and 'ESTABLISHED' for the
second packet.

This is an esoteric condition, as ruleset must permit NEW connections
in either direction and both peers must already have a bidirectional
traffic flow at the time conntrack gets enabled.

Allow the 'reverse' skb to pass and assign the existing (clashing)
entry.

While at it, also drop the extra 'dying' check, this is already
tested earlier by the calling function.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2024-09-26 13:01:54 +02:00
arch Networking changes for 6.12. 2024-09-16 06:02:27 +02:00
block block: Prevent deadlocks when switching elevators 2024-09-10 13:43:42 -06:00
certs kbuild: use $(src) instead of $(srctree)/$(src) for source directory 2024-05-10 04:34:52 +09:00
crypto crypto: testmgr - generate power-of-2 lengths more often 2024-07-13 11:50:28 +12:00
Documentation Documentation: networking: Fix missing PSE documentation and grammar issues 2024-09-13 19:59:53 -07:00
drivers Networking changes for 6.12. 2024-09-16 06:02:27 +02:00
fs fix for packet signing of write 2024-09-14 11:43:24 +02:00
include MIPS: Remove the obsoleted code for include/linux/mv643xx.h 2024-09-13 21:18:42 -07:00
init Rust fixes for v6.11 2024-08-16 11:24:06 -07:00
io_uring io_uring/kbuf: return correct iovec count from classic buffer peek 2024-08-30 10:45:54 -06:00
ipc sysctl: treewide: constify the ctl_table argument of proc_handlers 2024-07-24 20:59:29 +02:00
kernel Networking changes for 6.12. 2024-09-16 06:02:27 +02:00
lib Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2024-09-05 20:37:20 -07:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm mm: avoid leaving partial pfn mappings around in error case 2024-09-12 12:10:00 -07:00
net netfilter: conntrack: add clash resolution for reverse collisions 2024-09-26 13:01:54 +02:00
rust Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2024-09-05 20:37:20 -07:00
samples treewide: remove unnecessary <linux/version.h> inclusion 2024-08-12 18:36:44 +09:00
scripts scripts: fix gfp-translate after ___GFP_*_BITS conversion to an enum 2024-09-01 17:59:01 -07:00
security Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging 2024-09-01 09:18:48 +12:00
sound sound fixes for 6.11 2024-09-14 11:54:24 +02:00
tools selftests: fib_rule_tests: Add DSCP selector connect tests 2024-09-13 21:15:45 -07:00
usr initramfs: shorten cmd_initfs in usr/Makefile 2024-07-16 01:07:52 +09:00
virt KVM: x86: Disallow read-only memslots for SEV-ES and SEV-SNP (and TDX) 2024-08-14 12:28:24 -04:00
.clang-format Docs: Move clang-format from process/ to dev-tools/ 2024-06-26 16:36:00 -06:00
.cocciconfig
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore Add Jeff Kirsher to .get_maintainer.ignore 2024-03-08 11:36:54 +00:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore .gitignore: add .gcda files 2024-08-09 13:18:46 +01:00
.mailmap sound fixes for 6.11 2024-09-14 11:54:24 +02:00
.rustfmt.toml
COPYING
CREDITS tracing: Update of MAINTAINERS and CREDITS file 2024-07-18 14:08:42 -07:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig
MAINTAINERS Networking changes for 6.12. 2024-09-16 06:02:27 +02:00
Makefile Linux 6.11 2024-09-15 16:57:56 +02:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

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.