RFC 2516 Section 7 states that Protocol Field Compression (PFC) is NOT
RECOMMENDED for PPPoE. In practice, pppd does not support negotiating
PFC for PPPoE sessions, and the current PPPoE driver assumes an
uncompressed (2-byte) protocol field. However, the generic PPP layer
function ppp_input() is not aware of the negotiation result, and still
accepts PFC frames.

If a peer with a broken implementation or an attacker sends a frame with
a compressed (1-byte) protocol field, the subsequent PPP payload is
shifted by one byte. This causes the network header to be 4-byte
misaligned, which may trigger unaligned access exceptions on some
architectures.

To reduce the attack surface, drop PPPoE PFC frames. Introduce
ppp_skb_is_compressed_proto() helper function to be used in both
ppp_generic.c and pppoe.c to avoid open-coding.

Fixes: 7fb1b8ca8fa1 ("ppp: Move PFC decompression to PPP generic layer")
Signed-off-by: Qingfang Deng <qingfang.deng@linux.dev>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20260415022456.141758-2-qingfang.deng@linux.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Allow to dissect PPPoE specific fields which are:
- session ID (16 bits)
- ppp protocol (16 bits)
- type (16 bits) - this is PPPoE ethertype, for now only
  ETH_P_PPP_SES is supported, possible ETH_P_PPP_DISC
  in the future

The goal is to make the following TC command possible:

  # tc filter add dev ens6f0 ingress prio 1 protocol ppp_ses \
      flower \
        pppoe_sid 12 \
        ppp_proto ip \
      action drop

Note that only PPPoE Session is supported.

Signed-off-by: Wojciech Drewek <wojciech.drewek@intel.com>
Acked-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

Based on 2 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Michael Kerrisk <mtk.manpages@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Dave Jones <davej@redhat.com>

This changes the copyright notices on the PPP code that I developed
in the late 1990s from being copyright The Australian National
University to copyright Paul Mackerras.  I can do this as I have an
acknowledgement in writing from the Head of the Computer Science
Department at ANU (where I worked then) that ANU does not claim any
intellectual property in this code.

While I'm at it, change the copyright notice from BSD-style to
GNU GPL like the rest of the kernel.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

A number of standard posix types are used in exported headers, which
is not allowed if __STRICT_KERNEL_NAMES is defined. In order to
get rid of the non-__STRICT_KERNEL_NAMES part and to make sane headers
the default, we have to change them all to safe types.

There are also still some leftovers in reiserfs_fs.h, elfcore.h
and coda.h, but these files have not compiled in user space for
a long time.

This leaves out the various integer types ({u_,u,}int{8,16,32,64}_t),
which we take care of separately.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Cc: netdev@vger.kernel.org
Cc: linux-ppp@vger.kernel.org
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

fix the following 'make headers_check' warning:

  usr/include/linux/ppp_defs.h:50: found __[us]{8,16,32,64} type without #include <linux/types.h>

Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>

This patch removes CVS keywords that weren't updated for a long time
from comments.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: David Woodhouse <dwmw2@infradead.org>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!