Minimal supplement to upstream Kernel Self Protection Project changes. Features already provided by SELinux + Yama and archs other than multiarch arm64 / x86_64 aren't in scope. Only tags have stable history. Shared IRC channel with KSPP: irc.libera.chat #linux-hardening
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The incl_srcpt setting makes the switch mangle the destination MACs of multicast frames trapped to the CPU - a primitive tagging mechanism that works even when we cannot use the 802.1Q software features. The downside is that the two multicast MAC addresses that the switch traps for L2 PTP (01-80-C2-00-00-0E and 01-1B-19-00-00-00) quickly turn into a lot more, as the switch encodes the source port and switch id into bytes 3 and 4 of the MAC. The resulting range of MAC addresses would need to be installed manually into the DSA master port's multicast MAC filter, and even then, most devices might not have a large enough MAC filtering table. As a result, only limit use of incl_srcpt to when it's strictly necessary: when under a VLAN filtering bridge. This fixes PTP in non-bridged mode (standalone ports). Otherwise, PTP frames, as well as metadata follow-up frames holding RX timestamps won't be received because they will be blocked by the master port's MAC filter. Linuxptp doesn't help, because it only requests the addition of the unmodified PTP MACs to the multicast filter. This issue is not seen in bridged mode because the master port is put in promiscuous mode when the slave ports are enslaved to a bridge. Therefore, there is no downside to having the incl_srcpt mechanism active there. Signed-off-by: Vladimir Oltean <olteanv@gmail.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> |
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| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| 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 Restructured Text 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.