Hello Peter, Thank you. So for the sensors, we can keep LSM on. Cool. -Michael > On 14 Apr 2022, at 07:16, Peter Müller wrote: > > For the records: I spoke to Arne regarding this on the phone the other day. He confirmed to > me that this is by no means a severe issue from his point of view, and will check whether > firmware flashing continues to work with the hardened kernel. > >> Could you please check with Arne how severe this is for the sensors? >> >>> On 13 Apr 2022, at 10:18, Peter Müller wrote: >>> >>> Hello Michael, >>> >>> thanks for your e-mail. >>> >>> This is caused by the kernel lockdown patch, since /dev/ports apparently can be used to alter >>> the running kernel, hence it is no longer available if LSM runs in "integrity" mode. >>> >>> On my testing machine, sensors and sensors-detect continue to work, but any sensor that requires >>> /dev/ports access is no longer available. On my testing hardware, that does not make a difference, >>> but I presume it will on other hardware with more or different sensors. >>> >>> sensors-detect does not implement any option to probe non-/dev/ports-sensors only, so I guess >>> there is nothing we can do besides a "> /dev/null 2>&1". I will change the collectd initscript >>> to reflect that. >>> >>> Thanks, and best regards, >>> Peter Müller >>> >>> >>>> Hello, >>>> >>>> I don’t know exactly which patch is responsible for this, but /dev/port is no longer accessible by sensors-detect. >>>> >>>> This leads to ugly messages when the system is booting up for the first time. Please see the attached screenshot. >>>> >>>> At least the message needs to be silenced, but you should investigate whether sensors will still work and is able to access readings for its hardware sensors. >>>> >>>> >>>> >>>> -Michael >>>> >>>>> On 19 Mar 2022, at 21:08, Peter Müller wrote: >>>>> >>>>> This patchset improves hardening of our Linux kernel configurations for all >>>>> architectures. Most importantly, it features the activation of the "Linux >>>>> Security Module", also known as "kernel lockdown" (a phrase coined before the >>>>> pandemic), or LSM for short. >>>>> >>>>> Being set to "integrity" mode for a start, LSM prevents the kernel from being >>>>> modified by various mechanisms, of which we have some already covered. However, >>>>> it comes as a more holistic approach, which is why enabling it is desirable >>>>> for our userbase. >>>>> >>>>> Most of this patchset is based on recommendations by the "kconfig-hardened-check" >>>>> tool (https://github.com/a13xp0p0v/kconfig-hardened-check/), with some inspiration >>>>> taken directly from KSPP and grsecurity. >>>>> >>>>> Being unable to cross-compile IPFire for non-x86_64-architectures on my own, >>>>> and my VM on the Mustang currently being offline, this patchset does not come >>>>> with aligned kernel rootfiles for other architectures than x86_64. I am sorry >>>>> for any inconvenience and extra workload caused by this. >>>>> >>>>> Also, for the sake of completeness, the effect of LSM on virtualisation has not >>>>> been tested due to time constraints, and a lack of oversight _which_ virtualisation >>>>> features we officially support and which we don't. In doubt, however, I believe >>>>> the security benefit gained from LSM outweighs a partial functional loss of >>>>> virtualisation - but that is a highly biased opinion. :-) >>>>> >>>>> Peter Müller (11): >>>>> Kernel: Set CONFIG_ARCH_MMAP_RND_BITS to 32 bits >>>>> Kernel: Disable support for tracing block I/O actions >>>>> Kernel: Pin loading kernel files to one filesystem >>>>> Kernel: Enable undefined behaviour sanity checker >>>>> Kernel: Gate SETID transitions to limit CAP_SET(G|U)ID capabilities >>>>> Kernel: Enable LSM support and set security level to "integrity" >>>>> Kernel: Trigger BUG if data corruption is detected >>>>> Kernel: Do not automatically load TTY line disciplines, only if >>>>> necessary >>>>> Kernel: Enable SVA support for both Intel and AMD CPUs >>>>> Kernel: Disable function and stack tracers >>>>> Kernel: Update rootfile for x86_64 >>>>> >>>>> config/kernel/kernel.config.aarch64-ipfire | 47 ++++++++++-------- >>>>> config/kernel/kernel.config.armv6l-ipfire | 47 ++++++++++-------- >>>>> config/kernel/kernel.config.riscv64-ipfire | 47 ++++++++++-------- >>>>> config/kernel/kernel.config.x86_64-ipfire | 57 ++++++++++++---------- >>>>> config/rootfiles/common/x86_64/linux | 33 +++++++------ >>>>> 5 files changed, 131 insertions(+), 100 deletions(-) >>>>> >>>>> -- >>>>> 2.34.1 >>>> >>>> >>