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 >>> >>> >