user/sven/linux.git/include/linux/security.h, branch v5.6.10

security,lockdown,selinux: implement SELinux lockdown

2019-12-09T22:53:58Z

Implement a SELinux hook for lockdown. If the lockdown module is also enabled, then a denial by the lockdown module will take precedence over SELinux, so SELinux can only further restrict lockdown decisions. The SELinux hook only distinguishes at the granularity of integrity versus confidentiality similar to the lockdown module, but includes the full lockdown reason as part of the audit record as a hint in diagnosing what triggered the denial. To support this auditing, move the lockdown_reasons[] string array from being private to the lockdown module to the security framework so that it can be used by the lsm audit code and so that it is always available even when the lockdown module is disabled. Note that the SELinux implementation allows the integrity and confidentiality reasons to be controlled independently from one another. Thus, in an SELinux policy, one could allow operations that specify an integrity reason while blocking operations that specify a confidentiality reason. The SELinux hook implementation is stricter than the lockdown module in validating the provided reason value. Sample AVC audit output from denials: avc: denied { integrity } for pid=3402 comm="fwupd" lockdown_reason="/dev/mem,kmem,port" scontext=system_u:system_r:fwupd_t:s0 tcontext=system_u:system_r:fwupd_t:s0 tclass=lockdown permissive=0 avc: denied { confidentiality } for pid=4628 comm="cp" lockdown_reason="/proc/kcore access" scontext=unconfined_u:unconfined_r:test_lockdown_integrity_t:s0-s0:c0.c1023 tcontext=unconfined_u:unconfined_r:test_lockdown_integrity_t:s0-s0:c0.c1023 tclass=lockdown permissive=0 Signed-off-by: Stephen Smalley Reviewed-by: James Morris [PM: some merge fuzz do the the perf hooks] Signed-off-by: Paul Moore

Merge tag 'powerpc-5.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2019-11-30T22:35:43Z

Pull powerpc updates from Michael Ellerman: "Highlights: - Infrastructure for secure boot on some bare metal Power9 machines. The firmware support is still in development, so the code here won't actually activate secure boot on any existing systems. - A change to xmon (our crash handler / pseudo-debugger) to restrict it to read-only mode when the kernel is lockdown'ed, otherwise it's trivial to drop into xmon and modify kernel data, such as the lockdown state. - Support for KASLR on 32-bit BookE machines (Freescale / NXP). - Fixes for our flush_icache_range() and __kernel_sync_dicache() (VDSO) to work with memory ranges >4GB. - Some reworks of the pseries CMM (Cooperative Memory Management) driver to make it behave more like other balloon drivers and enable some cleanups of generic mm code. - A series of fixes to our hardware breakpoint support to properly handle unaligned watchpoint addresses. Plus a bunch of other smaller improvements, fixes and cleanups. Thanks to: Alastair D'Silva, Andrew Donnellan, Aneesh Kumar K.V, Anthony Steinhauser, Cédric Le Goater, Chris Packham, Chris Smart, Christophe Leroy, Christopher M. Riedl, Christoph Hellwig, Claudio Carvalho, Daniel Axtens, David Hildenbrand, Deb McLemore, Diana Craciun, Eric Richter, Geert Uytterhoeven, Greg Kroah-Hartman, Greg Kurz, Gustavo L. F. Walbon, Hari Bathini, Harish, Jason Yan, Krzysztof Kozlowski, Leonardo Bras, Mathieu Malaterre, Mauro S. M. Rodrigues, Michal Suchanek, Mimi Zohar, Nathan Chancellor, Nathan Lynch, Nayna Jain, Nick Desaulniers, Oliver O'Halloran, Qian Cai, Rasmus Villemoes, Ravi Bangoria, Sam Bobroff, Santosh Sivaraj, Scott Wood, Thomas Huth, Tyrel Datwyler, Vaibhav Jain, Valentin Longchamp, YueHaibing" * tag 'powerpc-5.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (144 commits) powerpc/fixmap: fix crash with HIGHMEM x86/efi: remove unused variables powerpc: Define arch_is_kernel_initmem_freed() for lockdep powerpc/prom_init: Use -ffreestanding to avoid a reference to bcmp powerpc: Avoid clang warnings around setjmp and longjmp powerpc: Don't add -mabi= flags when building with Clang powerpc: Fix Kconfig indentation powerpc/fixmap: don't clear fixmap area in paging_init() selftests/powerpc: spectre_v2 test must be built 64-bit powerpc/powernv: Disable native PCIe port management powerpc/kexec: Move kexec files into a dedicated subdir. powerpc/32: Split kexec low level code out of misc_32.S powerpc/sysdev: drop simple gpio powerpc/83xx: map IMMR with a BAT. powerpc/32s: automatically allocate BAT in setbat() powerpc/ioremap: warn on early use of ioremap() powerpc: Add support for GENERIC_EARLY_IOREMAP powerpc/fixmap: Use __fix_to_virt() instead of fix_to_virt() powerpc/8xx: use the fixmapped IMMR in cpm_reset() powerpc/8xx: add __init to cpm1 init functions ...

Merge tag 'v5.4-rc7' into perf/core, to pick up fixes

2019-11-11T06:59:06Z

Signed-off-by: Ingo Molnar

efi/efi_test: Lock down /dev/efi_test and require CAP_SYS_ADMIN

2019-10-31T08:40:21Z

The driver exposes EFI runtime services to user-space through an IOCTL interface, calling the EFI services function pointers directly without using the efivar API. Disallow access to the /dev/efi_test character device when the kernel is locked down to prevent arbitrary user-space to call EFI runtime services. Also require CAP_SYS_ADMIN to open the chardev to prevent unprivileged users to call the EFI runtime services, instead of just relying on the chardev file mode bits for this. The main user of this driver is the fwts [0] tool that already checks if the effective user ID is 0 and fails otherwise. So this change shouldn't cause any regression to this tool. [0]: https://wiki.ubuntu.com/FirmwareTestSuite/Reference/uefivarinfo Signed-off-by: Javier Martinez Canillas Signed-off-by: Ard Biesheuvel Acked-by: Laszlo Ersek Acked-by: Matthew Garrett Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-efi@vger.kernel.org Link: https://lkml.kernel.org/r/20191029173755.27149-7-ardb@kernel.org Signed-off-by: Ingo Molnar

powerpc/xmon: Restrict when kernel is locked down

2019-10-28T10:54:15Z

Xmon should be either fully or partially disabled depending on the kernel lockdown state. Put xmon into read-only mode for lockdown=integrity and prevent user entry into xmon when lockdown=confidentiality. Xmon checks the lockdown state on every attempted entry: (1) during early xmon'ing (2) when triggered via sysrq (3) when toggled via debugfs (4) when triggered via a previously enabled breakpoint The following lockdown state transitions are handled: (1) lockdown=none -> lockdown=integrity set xmon read-only mode (2) lockdown=none -> lockdown=confidentiality clear all breakpoints, set xmon read-only mode, prevent user re-entry into xmon (3) lockdown=integrity -> lockdown=confidentiality clear all breakpoints, set xmon read-only mode, prevent user re-entry into xmon Suggested-by: Andrew Donnellan Signed-off-by: Christopher M. Riedl Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20190907061124.1947-3-cmr@informatik.wtf

perf/core: Fix !CONFIG_PERF_EVENTS build warnings and failures

2019-10-19T07:15:27Z

sparc64 runs into this warning: include/linux/security.h:1913:52: warning: 'struct perf_event' declared inside parameter list will not be visible outside of this definition or declaration which is escalated to a build error in some of the .c files due to -Werror. Fix it via a forward declaration, like we do for perf_event_attr, the stub inlines don't actually need to know the structure of this struct. Fixes: da97e18458fb: ("perf_event: Add support for LSM and SELinux checks") Cc: "Joel Fernandes (Google)" Cc: linux-kernel@vger.kernel.org Cc: Peter Zijlstra Cc: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Alexander Shishkin Cc: Mark Rutland Cc: Namhyung Kim Signed-off-by: Ingo Molnar

perf_event: Add support for LSM and SELinux checks

2019-10-17T19:31:55Z

In current mainline, the degree of access to perf_event_open(2) system call depends on the perf_event_paranoid sysctl. This has a number of limitations: 1. The sysctl is only a single value. Many types of accesses are controlled based on the single value thus making the control very limited and coarse grained. 2. The sysctl is global, so if the sysctl is changed, then that means all processes get access to perf_event_open(2) opening the door to security issues. This patch adds LSM and SELinux access checking which will be used in Android to access perf_event_open(2) for the purposes of attaching BPF programs to tracepoints, perf profiling and other operations from userspace. These operations are intended for production systems. 5 new LSM hooks are added: 1. perf_event_open: This controls access during the perf_event_open(2) syscall itself. The hook is called from all the places that the perf_event_paranoid sysctl is checked to keep it consistent with the systctl. The hook gets passed a 'type' argument which controls CPU, kernel and tracepoint accesses (in this context, CPU, kernel and tracepoint have the same semantics as the perf_event_paranoid sysctl). Additionally, I added an 'open' type which is similar to perf_event_paranoid sysctl == 3 patch carried in Android and several other distros but was rejected in mainline [1] in 2016. 2. perf_event_alloc: This allocates a new security object for the event which stores the current SID within the event. It will be useful when the perf event's FD is passed through IPC to another process which may try to read the FD. Appropriate security checks will limit access. 3. perf_event_free: Called when the event is closed. 4. perf_event_read: Called from the read(2) and mmap(2) syscalls for the event. 5. perf_event_write: Called from the ioctl(2) syscalls for the event. [1] https://lwn.net/Articles/696240/ Since Peter had suggest LSM hooks in 2016 [1], I am adding his Suggested-by tag below. To use this patch, we set the perf_event_paranoid sysctl to -1 and then apply selinux checking as appropriate (default deny everything, and then add policy rules to give access to domains that need it). In the future we can remove the perf_event_paranoid sysctl altogether. Suggested-by: Peter Zijlstra Co-developed-by: Peter Zijlstra Signed-off-by: Joel Fernandes (Google) Signed-off-by: Peter Zijlstra (Intel) Acked-by: James Morris Cc: Arnaldo Carvalho de Melo Cc: rostedt@goodmis.org Cc: Yonghong Song Cc: Kees Cook Cc: Ingo Molnar Cc: Alexei Starovoitov Cc: jeffv@google.com Cc: Jiri Olsa Cc: Daniel Borkmann Cc: primiano@google.com Cc: Song Liu Cc: rsavitski@google.com Cc: Namhyung Kim Cc: Matthew Garrett Link: https://lkml.kernel.org/r/20191014170308.70668-1-joel@joelfernandes.org

Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security

2019-09-28T15:14:15Z

Pull kernel lockdown mode from James Morris: "This is the latest iteration of the kernel lockdown patchset, from Matthew Garrett, David Howells and others. From the original description: This patchset introduces an optional kernel lockdown feature, intended to strengthen the boundary between UID 0 and the kernel. When enabled, various pieces of kernel functionality are restricted. Applications that rely on low-level access to either hardware or the kernel may cease working as a result - therefore this should not be enabled without appropriate evaluation beforehand. The majority of mainstream distributions have been carrying variants of this patchset for many years now, so there's value in providing a doesn't meet every distribution requirement, but gets us much closer to not requiring external patches. There are two major changes since this was last proposed for mainline: - Separating lockdown from EFI secure boot. Background discussion is covered here: https://lwn.net/Articles/751061/ - Implementation as an LSM, with a default stackable lockdown LSM module. This allows the lockdown feature to be policy-driven, rather than encoding an implicit policy within the mechanism. The new locked_down LSM hook is provided to allow LSMs to make a policy decision around whether kernel functionality that would allow tampering with or examining the runtime state of the kernel should be permitted. The included lockdown LSM provides an implementation with a simple policy intended for general purpose use. This policy provides a coarse level of granularity, controllable via the kernel command line: lockdown={integrity|confidentiality} Enable the kernel lockdown feature. If set to integrity, kernel features that allow userland to modify the running kernel are disabled. If set to confidentiality, kernel features that allow userland to extract confidential information from the kernel are also disabled. This may also be controlled via /sys/kernel/security/lockdown and overriden by kernel configuration. New or existing LSMs may implement finer-grained controls of the lockdown features. Refer to the lockdown_reason documentation in include/linux/security.h for details. The lockdown feature has had signficant design feedback and review across many subsystems. This code has been in linux-next for some weeks, with a few fixes applied along the way. Stephen Rothwell noted that commit 9d1f8be5cf42 ("bpf: Restrict bpf when kernel lockdown is in confidentiality mode") is missing a Signed-off-by from its author. Matthew responded that he is providing this under category (c) of the DCO" * 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (31 commits) kexec: Fix file verification on S390 security: constify some arrays in lockdown LSM lockdown: Print current->comm in restriction messages efi: Restrict efivar_ssdt_load when the kernel is locked down tracefs: Restrict tracefs when the kernel is locked down debugfs: Restrict debugfs when the kernel is locked down kexec: Allow kexec_file() with appropriate IMA policy when locked down lockdown: Lock down perf when in confidentiality mode bpf: Restrict bpf when kernel lockdown is in confidentiality mode lockdown: Lock down tracing and perf kprobes when in confidentiality mode lockdown: Lock down /proc/kcore x86/mmiotrace: Lock down the testmmiotrace module lockdown: Lock down module params that specify hardware parameters (eg. ioport) lockdown: Lock down TIOCSSERIAL lockdown: Prohibit PCMCIA CIS storage when the kernel is locked down acpi: Disable ACPI table override if the kernel is locked down acpi: Ignore acpi_rsdp kernel param when the kernel has been locked down ACPI: Limit access to custom_method when the kernel is locked down x86/msr: Restrict MSR access when the kernel is locked down x86: Lock down IO port access when the kernel is locked down ...

Merge tag 'selinux-pr-20190917' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux

2019-09-23T18:21:04Z

Pull selinux updates from Paul Moore: - Add LSM hooks, and SELinux access control hooks, for dnotify, fanotify, and inotify watches. This has been discussed with both the LSM and fs/notify folks and everybody is good with these new hooks. - The LSM stacking changes missed a few calls to current_security() in the SELinux code; we fix those and remove current_security() for good. - Improve our network object labeling cache so that we always return the object's label, even when under memory pressure. Previously we would return an error if we couldn't allocate a new cache entry, now we always return the label even if we can't create a new cache entry for it. - Convert the sidtab atomic_t counter to a normal u32 with READ/WRITE_ONCE() and memory barrier protection. - A few patches to policydb.c to clean things up (remove forward declarations, long lines, bad variable names, etc) * tag 'selinux-pr-20190917' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux: lsm: remove current_security() selinux: fix residual uses of current_security() for the SELinux blob selinux: avoid atomic_t usage in sidtab fanotify, inotify, dnotify, security: add security hook for fs notifications selinux: always return a secid from the network caches if we find one selinux: policydb - rename type_val_to_struct_array selinux: policydb - fix some checkpatch.pl warnings selinux: shuffle around policydb.c to get rid of forward declarations

tracefs: Restrict tracefs when the kernel is locked down

2019-08-20T04:54:17Z

Tracefs may release more information about the kernel than desirable, so restrict it when the kernel is locked down in confidentiality mode by preventing open(). (Fixed by Ben Hutchings to avoid a null dereference in default_file_open()) Signed-off-by: Matthew Garrett Reviewed-by: Steven Rostedt (VMware) Cc: Ben Hutchings Signed-off-by: James Morris