mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-11-30 09:06:44 +07:00
1404d6f13e
Page mappings with full RWX permissions are a security risk. x86
has an option to walk the page tables and dump any bad pages.
(See e1a58320a3 ("x86/mm: Warn on W^X mappings")). Add a similar
implementation for arm64.
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Laura Abbott <labbott@redhat.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
[catalin.marinas@arm.com: folded fix for KASan out of bounds from Mark Rutland]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
101 lines
3.4 KiB
Plaintext
101 lines
3.4 KiB
Plaintext
menu "Kernel hacking"
|
|
|
|
source "lib/Kconfig.debug"
|
|
|
|
config ARM64_PTDUMP_CORE
|
|
def_bool n
|
|
|
|
config ARM64_PTDUMP_DEBUGFS
|
|
bool "Export kernel pagetable layout to userspace via debugfs"
|
|
depends on DEBUG_KERNEL
|
|
select ARM64_PTDUMP_CORE
|
|
select DEBUG_FS
|
|
help
|
|
Say Y here if you want to show the kernel pagetable layout in a
|
|
debugfs file. This information is only useful for kernel developers
|
|
who are working in architecture specific areas of the kernel.
|
|
It is probably not a good idea to enable this feature in a production
|
|
kernel.
|
|
|
|
If in doubt, say N.
|
|
|
|
config PID_IN_CONTEXTIDR
|
|
bool "Write the current PID to the CONTEXTIDR register"
|
|
help
|
|
Enabling this option causes the kernel to write the current PID to
|
|
the CONTEXTIDR register, at the expense of some additional
|
|
instructions during context switch. Say Y here only if you are
|
|
planning to use hardware trace tools with this kernel.
|
|
|
|
config ARM64_RANDOMIZE_TEXT_OFFSET
|
|
bool "Randomize TEXT_OFFSET at build time"
|
|
help
|
|
Say Y here if you want the image load offset (AKA TEXT_OFFSET)
|
|
of the kernel to be randomized at build-time. When selected,
|
|
this option will cause TEXT_OFFSET to be randomized upon any
|
|
build of the kernel, and the offset will be reflected in the
|
|
text_offset field of the resulting Image. This can be used to
|
|
fuzz-test bootloaders which respect text_offset.
|
|
|
|
This option is intended for bootloader and/or kernel testing
|
|
only. Bootloaders must make no assumptions regarding the value
|
|
of TEXT_OFFSET and platforms must not require a specific
|
|
value.
|
|
|
|
config DEBUG_WX
|
|
bool "Warn on W+X mappings at boot"
|
|
select ARM64_PTDUMP_CORE
|
|
---help---
|
|
Generate a warning if any W+X mappings are found at boot.
|
|
|
|
This is useful for discovering cases where the kernel is leaving
|
|
W+X mappings after applying NX, as such mappings are a security risk.
|
|
This check also includes UXN, which should be set on all kernel
|
|
mappings.
|
|
|
|
Look for a message in dmesg output like this:
|
|
|
|
arm64/mm: Checked W+X mappings: passed, no W+X pages found.
|
|
|
|
or like this, if the check failed:
|
|
|
|
arm64/mm: Checked W+X mappings: FAILED, <N> W+X pages found.
|
|
|
|
Note that even if the check fails, your kernel is possibly
|
|
still fine, as W+X mappings are not a security hole in
|
|
themselves, what they do is that they make the exploitation
|
|
of other unfixed kernel bugs easier.
|
|
|
|
There is no runtime or memory usage effect of this option
|
|
once the kernel has booted up - it's a one time check.
|
|
|
|
If in doubt, say "Y".
|
|
|
|
config DEBUG_SET_MODULE_RONX
|
|
bool "Set loadable kernel module data as NX and text as RO"
|
|
depends on MODULES
|
|
default y
|
|
help
|
|
Is this is set, kernel module text and rodata will be made read-only.
|
|
This is to help catch accidental or malicious attempts to change the
|
|
kernel's executable code.
|
|
|
|
If in doubt, say Y.
|
|
|
|
config DEBUG_ALIGN_RODATA
|
|
depends on DEBUG_RODATA
|
|
bool "Align linker sections up to SECTION_SIZE"
|
|
help
|
|
If this option is enabled, sections that may potentially be marked as
|
|
read only or non-executable will be aligned up to the section size of
|
|
the kernel. This prevents sections from being split into pages and
|
|
avoids a potential TLB penalty. The downside is an increase in
|
|
alignment and potentially wasted space. Turn on this option if
|
|
performance is more important than memory pressure.
|
|
|
|
If in doubt, say N.
|
|
|
|
source "drivers/hwtracing/coresight/Kconfig"
|
|
|
|
endmenu
|