To quote from the kernel documentation:
> Historically the kernel has allowed TIOCSTI, which will push
> characters into a controlling TTY. This continues to be used
> as a malicious privilege escalation mechanism, and provides no
> meaningful real-world utility any more. Its use is considered
> a dangerous legacy operation, and can be disabled on most
> systems.
>
> Say Y here only if you have confirmed that your system's
> userspace depends on this functionality to continue operating
> normally.
>
> Processes which run with CAP_SYS_ADMIN, such as BRLTTY, can
> use TIOCSTI even when this is set to N.
>
> This functionality can be changed at runtime with the
> dev.tty.legacy_tiocsti sysctl. This configuration option sets
> the default value of the sysctl.
This patch therefore proposes to no longer allow legacy TIOCSTI usage
in IPFire, given its security implications and the apparent lack of
legitimate usage.
Signed-off-by: Peter Müller <peter.mueller@ipfire.org>
Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>
This subsystem has been a frequent source of security vulnerabilities
affecting the Linux kernel; as a result, Google announced on June 14,
2023, that they would disable it in their environment as widely as
possible.
IPFire does not depend on the availability of io_uring. Therefore,
disable this subsystem as well in order to preemptively cut attack
surface.
See also: https://security.googleblog.com/2023/06/learnings-from-kctf-vrps-42-linux.html
Signed-off-by: Peter Müller <peter.mueller@ipfire.org>
Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>
From the kernel documentation:
> Driver for the internal USB role switch for switching the USB data
> lines between the xHCI host controller and the dwc3 gadget controller
> found on various Intel SoCs. [...]
This may unblock USB-LAN-adaptor usage on certain boards, as reported
once in #12750. Overall affected devices seem to be scanty;
nevertheless, enabling this as a module only is highly unlikely to cause
any harm, so let's give it a try.
Signed-off-by: Peter Müller <peter.mueller@ipfire.org>
Compiling the kernel has automatically introduced
CONFIG_INIT_STACK_ALL_ZERO=y and removed GCC's structleak plugin (not to
be confused with its stackleak counterpart). However, according to
related documentation, this neither introduces a security nor
performance disadvantage.
Signed-off-by: Peter Müller <peter.mueller@ipfire.org>
Reviewed-by: Michael Tremer <michael.tremer@ipfire.org>
It does not generate cryptographically secure entropy.
Backported from IPFire 3.x as 6aea180b26906f001611dcc0c54f494818069d8c.
Signed-off-by: Peter Müller <peter.mueller@ipfire.org>
Acked-by: Michael Tremer <michael.tremer@ipfire.org>
This patch also compiles all sorts of device mapper stuff as modules.
Backported from IPFire 3.x as 6fe31a44d07d8705ca7713c449ccbb3dbb9684a0.
Signed-off-by: Peter Müller <peter.mueller@ipfire.org>
Acked-by: Michael Tremer <michael.tremer@ipfire.org>
This is disabled in IPFire 3.x, and projects such as grsecurity
recommend doing so for security reasons as well. Also, skimming through
our source code, there is no point where this ACPI configfs would have
been explicitly mounted, which leads to the assumption that we never
used it anyway.
Signed-off-by: Peter Müller <peter.mueller@ipfire.org>
Acked-by: Michael Tremer <michael.tremer@ipfire.org>
