To quote from the kernel documentation:
> If you say Y here, the layouts of structures that are entirely
> function pointers (and have not been manually annotated with
> __no_randomize_layout), or structures that have been explicitly
> marked with __randomize_layout, will be randomized at compile-time.
> This can introduce the requirement of an additional information
> exposure vulnerability for exploits targeting these structure
> types.
>
> Enabling this feature will introduce some performance impact,
> slightly increase memory usage, and prevent the use of forensic
> tools like Volatility against the system (unless the kernel
> source tree isn't cleaned after kernel installation).
>
> The seed used for compilation is located at
> scripts/gcc-plgins/randomize_layout_seed.h. It remains after
> a make clean to allow for external modules to be compiled with
> the existing seed and will be removed by a make mrproper or
> make distclean.
>
> Note that the implementation requires gcc 4.7 or newer.
Signed-off-by: Peter Müller <peter.mueller@ipfire.org>
Acked-by: Michael Tremer <michael.tremer@ipfire.org>
If available, the kernel will enable IOMMU (a/k/a DMA remapping) by
default on boot. To tools making use of that, particularly hypervisors,
this provides better security without any downsides.
Signed-off-by: Peter Müller <peter.mueller@ipfire.org>
This patch, which has been merged into the mainline Linux kernel, but
not yet backported to the 5.15.x tree, precisely addresses our
situation: IPFire does not use systemd, but CONFIG_DEVTMPFS_MOUNT.
The only explanation I have for bug #12889 arising _now_ is that some
component (dracut, maybe) changed its behaviour regarding remounting of
already mounted special file systems. As current dracut won't (re)mount
any file system already found to be mounted, this means that the mount
options decided by the kernel remained untouched for /dev, hence being
weak in terms of options hardening possible.
As CONFIG_DEVTMPFS_SAFE would not show up in "make menuconfig", changes
to kernel configurations have been simulated.
Fixes: #12889
Cc: Michael Tremer <michael.tremer@ipfire.org>
Signed-off-by: Peter Müller <peter.mueller@ipfire.org>
This is solely needed for debugging of NFS issues. Due to the attack
surface it introduces, grsecurity recommends to disable it; as we do not
have a strict necessity for this feature, it is best to follow that
recommendation for security reasons.
Signed-off-by: Peter Müller <peter.mueller@ipfire.org>
Reviewed-by: Michael Tremer <michael.tremer@ipfire.org>
in kernel 5.15.32 the driver for ATH9K wlan cards is unstable.
This is one of the most used cards so we need this update before
releasing core167 final.
Signed-off-by: Arne Fitzenreiter <arne_f@ipfire.org>
LSM was found to render firmware flashing unusable, and patching out LSM
functionality for all features needed (such as /dev/io, direct memory
access and probably raw PCI access for older cards), this would
effectively render much of LSM's functionality useless as well.
For the time being, we do ship LSM, but do not enforce any protection
mode. Users hence can run it in "integrity" or even "confidentiality"
mode by custom commands; hopefully, we will be able to revert this
change at a future point.
Acked-by: Arne Fitzenreiter <arne.fitzenreiter@ipfire.org>
Signed-off-by: Peter Müller <peter.mueller@ipfire.org>
Since running virtual machines is one of our legitimate use cases, it
makes sense to provide Qemu with the ability of taking advantage of
IOMMU support for safer virtuall memory allocation, if available.
Signed-off-by: Peter Müller <peter.mueller@ipfire.org>
Acked-by: Michael Tremer <michael.tremer@ipfire.org>
This is not necessary on our systems and according to the documentation
will reduce code size of the allocator which will result in better
performance.
Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>
Acked-by: Peter Müller <peter.mueller@ipfire.org>
Signed-off-by: Arne Fitzenreiter <arne_f@ipfire.org>
This is a new type of metric to find out what resource is currently a
bottleneck for the whole system. We might use this for graphs.
Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>
Acked-by: Peter Müller <peter.mueller@ipfire.org>
Signed-off-by: Arne Fitzenreiter <arne_f@ipfire.org>
This feature is now disabled (was disabled on ARM before) as we do not
need it:
"Select this option to enable fine granularity task irq time accounting.
This is done by reading a timestamp on each transitions between softirq
and hardirq state, so there can be a small performance impact."
Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>
Acked-by: Peter Müller <peter.mueller@ipfire.org>
Signed-off-by: Arne Fitzenreiter <arne_f@ipfire.org>
