113 Commits
Author SHA1 Message Date
Linus Torvalds 599bbba5a3 proc: make PROC_MEM_FORCE_PTRACE the Kconfig default
This kconfig option was introduced 18 months ago, with the historical
default of always allowing forcing memory permission overrides in order
to not change any existing behavior.

But it was documented as "for now", and this is a gentle nudge to people
that you probably _should_ be using PROC_MEM_FORCE_PTRACE.  I've had
that in my local kernel config since the option was introduced.

Anybody who just does "make oldconfig" will pick up their old
configuration with no change, so this is still meant to not change any
existing system behavior, but at least gently prod people into trying
it.

I'd love to get rid of FOLL_FORCE entirely (see commit 8ee74a91ac
"proc: try to remove use of FOLL_FORCE entirely" from roughly a decade
ago), but sadly that is likely not a realistic option (see commit
f511c0b17b "Yes, people use FOLL_FORCE ;)" three weeks later).

But at least let's make it more obvious that you have the choice to
limit it and force people to at least be a bit more conscious about
their use of FOLL_FORCE, since judging from a recent discussion people
weren't even aware of this one.

Reminded-by: Vova Tokarev <vladimirelitokarev@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-04-13 09:12:37 -07:00
Ryan FosterandSerge Hallyn 24e9b431b5 security: Add KUnit tests for kuid_root_in_ns and vfsuid_root_in_currentns
Add comprehensive KUnit tests for the namespace-related capability
functions that Serge Hallyn refactored in commit 9891d2f79a
("Clarify the rootid_owns_currentns").

The tests verify:
- Basic functionality: UID 0 in init namespace, invalid vfsuid,
  non-zero UIDs
- Actual namespace traversal: Creating user namespaces with different
  UID mappings where uid 0 maps to different kuids (e.g., 1000, 2000,
  3000)
- Hierarchy traversal: Testing multiple nested namespaces to verify
  correct namespace hierarchy traversal

This addresses the feedback to "test the actual functionality" by
creating real user namespaces with different values for the
namespace's uid 0, rather than just basic input validation.

The test file is included at the end of commoncap.c when
CONFIG_SECURITY_COMMONCAP_KUNIT_TEST is enabled, following the
standard kernel pattern (e.g., scsi_lib.c, ext4/mballoc.c). This
allows tests to access static functions in the same compilation unit
without modifying production code based on test configuration.

The tests require CONFIG_USER_NS to be enabled since they rely on user
namespace mapping functionality. The Kconfig dependency ensures the
tests only build when this requirement is met.

All 7 tests pass:
- test_vfsuid_root_in_currentns_init_ns
- test_vfsuid_root_in_currentns_invalid
- test_vfsuid_root_in_currentns_nonzero
- test_kuid_root_in_ns_init_ns_uid0
- test_kuid_root_in_ns_init_ns_nonzero
- test_kuid_root_in_ns_with_mapping
- test_kuid_root_in_ns_with_different_mappings

Updated MAINTAINER capabilities to include commoncap test

Signed-off-by: Ryan Foster <foster.ryan.r@gmail.com>
Signed-off-by: Serge Hallyn <sergeh@kernel.org>
2026-01-09 11:28:28 -06:00
Randy DunlapandPaul Moore 54d94c422f lsm: CONFIG_LSM can depend on CONFIG_SECURITY
When CONFIG_SECURITY is not set, CONFIG_LSM (builtin_lsm_order) does
not need to be visible and settable since builtin_lsm_order is defined in
security.o, which is only built when CONFIG_SECURITY=y.

So make CONFIG_LSM depend on CONFIG_SECURITY.

Fixes: 13e735c0e9 ("LSM: Introduce CONFIG_LSM")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
[PM: subj tweak]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2025-09-11 16:32:04 -04:00
Jeff XuandAndrew Morton 5796d3967c mseal sysmap: kernel config and header change
Patch series "mseal system mappings", v9.

As discussed during mseal() upstream process [1], mseal() protects the
VMAs of a given virtual memory range against modifications, such as the
read/write (RW) and no-execute (NX) bits.  For complete descriptions of
memory sealing, please see mseal.rst [2].

The mseal() is useful to mitigate memory corruption issues where a
corrupted pointer is passed to a memory management system.  For example,
such an attacker primitive can break control-flow integrity guarantees
since read-only memory that is supposed to be trusted can become writable
or .text pages can get remapped.

The system mappings are readonly only, memory sealing can protect them
from ever changing to writable or unmmap/remapped as different attributes.

System mappings such as vdso, vvar, vvar_vclock, vectors (arm
compat-mode), sigpage (arm compat-mode), are created by the kernel during
program initialization, and could be sealed after creation.

Unlike the aforementioned mappings, the uprobe mapping is not established
during program startup.  However, its lifetime is the same as the
process's lifetime [3].  It could be sealed from creation.

The vsyscall on x86-64 uses a special address (0xffffffffff600000), which
is outside the mm managed range.  This means mprotect, munmap, and mremap
won't work on the vsyscall.  Since sealing doesn't enhance the vsyscall's
security, it is skipped in this patch.  If we ever seal the vsyscall, it
is probably only for decorative purpose, i.e.  showing the 'sl' flag in
the /proc/pid/smaps.  For this patch, it is ignored.

It is important to note that the CHECKPOINT_RESTORE feature (CRIU) may
alter the system mappings during restore operations.  UML(User Mode Linux)
and gVisor, rr are also known to change the vdso/vvar mappings. 
Consequently, this feature cannot be universally enabled across all
systems.  As such, CONFIG_MSEAL_SYSTEM_MAPPINGS is disabled by default.

To support mseal of system mappings, architectures must define
CONFIG_ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS and update their special
mappings calls to pass mseal flag.  Additionally, architectures must
confirm they do not unmap/remap system mappings during the process
lifetime.  The existence of this flag for an architecture implies that it
does not require the remapping of thest system mappings during process
lifetime, so sealing these mappings is safe from a kernel perspective.

This version covers x86-64 and arm64 archiecture as minimum viable feature.

While no specific CPU hardware features are required for enable this
feature on an archiecture, memory sealing requires a 64-bit kernel.  Other
architectures can choose whether or not to adopt this feature.  Currently,
I'm not aware of any instances in the kernel code that actively
munmap/mremap a system mapping without a request from userspace.  The PPC
does call munmap when _install_special_mapping fails for vdso; however,
it's uncertain if this will ever fail for PPC - this needs to be
investigated by PPC in the future [4].  The UML kernel can add this
support when KUnit tests require it [5].

In this version, we've improved the handling of system mapping sealing
from previous versions, instead of modifying the _install_special_mapping
function itself, which would affect all architectures, we now call
_install_special_mapping with a sealing flag only within the specific
architecture that requires it.  This targeted approach offers two key
advantages: 1) It limits the code change's impact to the necessary
architectures, and 2) It aligns with the software architecture by keeping
the core memory management within the mm layer, while delegating the
decision of sealing system mappings to the individual architecture, which
is particularly relevant since 32-bit architectures never require sealing.

Prior to this patch series, we explored sealing special mappings from
userspace using glibc's dynamic linker.  This approach revealed several
issues:

- The PT_LOAD header may report an incorrect length for vdso, (smaller
  than its actual size).  The dynamic linker, which relies on PT_LOAD
  information to determine mapping size, would then split and partially
  seal the vdso mapping.  Since each architecture has its own vdso/vvar
  code, fixing this in the kernel would require going through each
  archiecture.  Our initial goal was to enable sealing readonly mappings,
  e.g.  .text, across all architectures, sealing vdso from kernel since
  creation appears to be simpler than sealing vdso at glibc.

- The [vvar] mapping header only contains address information, not
  length information.  Similar issues might exist for other special
  mappings.

- Mappings like uprobe are not covered by the dynamic linker, and there
  is no effective solution for them.

This feature's security enhancements will benefit ChromeOS, Android, and
other high security systems.

Testing:
This feature was tested on ChromeOS and Android for both x86-64 and ARM64.
- Enable sealing and verify vdso/vvar, sigpage, vector are sealed properly,
  i.e. "sl" shown in the smaps for those mappings, and mremap is blocked.
- Passing various automation tests (e.g. pre-checkin) on ChromeOS and
  Android to ensure the sealing doesn't affect the functionality of
  Chromebook and Android phone.

I also tested the feature on Ubuntu on x86-64:
- With config disabled, vdso/vvar is not sealed,
- with config enabled, vdso/vvar is sealed, and booting up Ubuntu is OK,
  normal operations such as browsing the web, open/edit doc are OK.

Link: https://lore.kernel.org/all/20240415163527.626541-1-jeffxu@chromium.org/ [1]
Link: Documentation/userspace-api/mseal.rst [2]
Link: https://lore.kernel.org/all/CABi2SkU9BRUnqf70-nksuMCQ+yyiWjo3fM4XkRkL-NrCZxYAyg@mail.gmail.com/ [3]
Link: https://lore.kernel.org/all/CABi2SkV6JJwJeviDLsq9N4ONvQ=EFANsiWkgiEOjyT9TQSt+HA@mail.gmail.com/ [4]
Link: https://lore.kernel.org/all/202502251035.239B85A93@keescook/ [5]


This patch (of 7):

Provide infrastructure to mseal system mappings.  Establish two kernel
configs (CONFIG_MSEAL_SYSTEM_MAPPINGS,
ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS) and VM_SEALED_SYSMAP macro for future
patches.

Link: https://lkml.kernel.org/r/20250305021711.3867874-1-jeffxu@google.com
Link: https://lkml.kernel.org/r/20250305021711.3867874-2-jeffxu@google.com
Signed-off-by: Jeff Xu <jeffxu@chromium.org>
Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Cc: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Anna-Maria Behnsen <anna-maria@linutronix.de>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Benjamin Berg <benjamin@sipsolutions.net>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Elliot Hughes <enh@google.com>
Cc: Florian Faineli <f.fainelli@gmail.com>
Cc: Greg Ungerer <gerg@kernel.org>
Cc: Guenter Roeck <groeck@chromium.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: Jason A. Donenfeld <jason@zx2c4.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Jorge Lucangeli Obes <jorgelo@chromium.org>
Cc: Linus Waleij <linus.walleij@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcow (Oracle) <willy@infradead.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Mike Rapoport <mike.rapoport@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Pedro Falcato <pedro.falcato@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Stephen Röttger <sroettger@google.com>
Cc: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-04-01 15:17:14 -07:00
Mel GormanandKees Cook ca758b147e fortify: Move FORTIFY_SOURCE under 'Kernel hardening options'
FORTIFY_SOURCE is a hardening option both at build and runtime. Move
it under 'Kernel hardening options'.

Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Paul Moore <paul@paul-moore.com>
Link: https://lore.kernel.org/r/20250123221115.19722-5-mgorman@techsingularity.net
Signed-off-by: Kees Cook <kees@kernel.org>
2025-02-28 11:51:31 -08:00
Mel GormanandKees Cook f4d4e8b9d6 mm: security: Move hardened usercopy under 'Kernel hardening options'
There is a submenu for 'Kernel hardening options' under "Security".
Move HARDENED_USERCOPY under the hardening options as it is clearly
related.

Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Paul Moore <paul@paul-moore.com>
Link: https://lore.kernel.org/r/20250123221115.19722-2-mgorman@techsingularity.net
Signed-off-by: Kees Cook <kees@kernel.org>
2025-02-28 11:51:31 -08:00
Mickaël SalaünandPaul Moore 7ccbe076d9 lsm: Only build lsm_audit.c if CONFIG_SECURITY and CONFIG_AUDIT are set
When CONFIG_AUDIT is set, its CONFIG_NET dependency is also set, and the
dev_get_by_index and init_net symbols (used by dump_common_audit_data)
are found by the linker.  dump_common_audit_data() should then failed to
build when CONFIG_NET is not set. However, because the compiler is
smart, it knows that audit_log_start() always return NULL when
!CONFIG_AUDIT, and it doesn't build the body of common_lsm_audit().  As
a side effect, dump_common_audit_data() is not built and the linker
doesn't error out because of missing symbols.

Let's only build lsm_audit.o when CONFIG_SECURITY and CONFIG_AUDIT are
both set, which is checked with the new CONFIG_HAS_SECURITY_AUDIT.

ipv4_skb_to_auditdata() and ipv6_skb_to_auditdata() are only used by
Smack if CONFIG_AUDIT is set, so they don't need fake implementations.

Because common_lsm_audit() is used in multiple places without
CONFIG_AUDIT checks, add a fake implementation.

Link: https://lore.kernel.org/r/20241122143353.59367-2-mic@digikod.net
Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: James Morris <jmorris@namei.org>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Serge E. Hallyn <serge@hallyn.com>
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2025-01-04 11:50:44 -05:00
Linus Torvalds a430d95c5e Merge tag 'lsm-pr-20240911' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm
Pull lsm updates from Paul Moore:

 - Move the LSM framework to static calls

   This transitions the vast majority of the LSM callbacks into static
   calls. Those callbacks which haven't been converted were left as-is
   due to the general ugliness of the changes required to support the
   static call conversion; we can revisit those callbacks at a future
   date.

 - Add the Integrity Policy Enforcement (IPE) LSM

   This adds a new LSM, Integrity Policy Enforcement (IPE). There is
   plenty of documentation about IPE in this patches, so I'll refrain
   from going into too much detail here, but the basic motivation behind
   IPE is to provide a mechanism such that administrators can restrict
   execution to only those binaries which come from integrity protected
   storage, e.g. a dm-verity protected filesystem. You will notice that
   IPE requires additional LSM hooks in the initramfs, dm-verity, and
   fs-verity code, with the associated patches carrying ACK/review tags
   from the associated maintainers. We couldn't find an obvious
   maintainer for the initramfs code, but the IPE patchset has been
   widely posted over several years.

   Both Deven Bowers and Fan Wu have contributed to IPE's development
   over the past several years, with Fan Wu agreeing to serve as the IPE
   maintainer moving forward. Once IPE is accepted into your tree, I'll
   start working with Fan to ensure he has the necessary accounts, keys,
   etc. so that he can start submitting IPE pull requests to you
   directly during the next merge window.

 - Move the lifecycle management of the LSM blobs to the LSM framework

   Management of the LSM blobs (the LSM state buffers attached to
   various kernel structs, typically via a void pointer named "security"
   or similar) has been mixed, some blobs were allocated/managed by
   individual LSMs, others were managed by the LSM framework itself.

   Starting with this pull we move management of all the LSM blobs,
   minus the XFRM blob, into the framework itself, improving consistency
   across LSMs, and reducing the amount of duplicated code across LSMs.
   Due to some additional work required to migrate the XFRM blob, it has
   been left as a todo item for a later date; from a practical
   standpoint this omission should have little impact as only SELinux
   provides a XFRM LSM implementation.

 - Fix problems with the LSM's handling of F_SETOWN

   The LSM hook for the fcntl(F_SETOWN) operation had a couple of
   problems: it was racy with itself, and it was disconnected from the
   associated DAC related logic in such a way that the LSM state could
   be updated in cases where the DAC state would not. We fix both of
   these problems by moving the security_file_set_fowner() hook into the
   same section of code where the DAC attributes are updated. Not only
   does this resolve the DAC/LSM synchronization issue, but as that code
   block is protected by a lock, it also resolve the race condition.

 - Fix potential problems with the security_inode_free() LSM hook

   Due to use of RCU to protect inodes and the placement of the LSM hook
   associated with freeing the inode, there is a bit of a challenge when
   it comes to managing any LSM state associated with an inode. The VFS
   folks are not open to relocating the LSM hook so we have to get
   creative when it comes to releasing an inode's LSM state.
   Traditionally we have used a single LSM callback within the hook that
   is triggered when the inode is "marked for death", but not actually
   released due to RCU.

   Unfortunately, this causes problems for LSMs which want to take an
   action when the inode's associated LSM state is actually released; so
   we add an additional LSM callback, inode_free_security_rcu(), that is
   called when the inode's LSM state is released in the RCU free
   callback.

 - Refactor two LSM hooks to better fit the LSM return value patterns

   The vast majority of the LSM hooks follow the "return 0 on success,
   negative values on failure" pattern, however, there are a small
   handful that have unique return value behaviors which has caused
   confusion in the past and makes it difficult for the BPF verifier to
   properly vet BPF LSM programs. This includes patches to
   convert two of these"special" LSM hooks to the common 0/-ERRNO pattern.

 - Various cleanups and improvements

   A handful of patches to remove redundant code, better leverage the
   IS_ERR_OR_NULL() helper, add missing "static" markings, and do some
   minor style fixups.

* tag 'lsm-pr-20240911' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm: (40 commits)
  security: Update file_set_fowner documentation
  fs: Fix file_set_fowner LSM hook inconsistencies
  lsm: Use IS_ERR_OR_NULL() helper function
  lsm: remove LSM_COUNT and LSM_CONFIG_COUNT
  ipe: Remove duplicated include in ipe.c
  lsm: replace indirect LSM hook calls with static calls
  lsm: count the LSMs enabled at compile time
  kernel: Add helper macros for loop unrolling
  init/main.c: Initialize early LSMs after arch code, static keys and calls.
  MAINTAINERS: add IPE entry with Fan Wu as maintainer
  documentation: add IPE documentation
  ipe: kunit test for parser
  scripts: add boot policy generation program
  ipe: enable support for fs-verity as a trust provider
  fsverity: expose verified fsverity built-in signatures to LSMs
  lsm: add security_inode_setintegrity() hook
  ipe: add support for dm-verity as a trust provider
  dm-verity: expose root hash digest and signature data to LSMs
  block,lsm: add LSM blob and new LSM hooks for block devices
  ipe: add permissive toggle
  ...
2024-09-16 18:19:47 +02:00
Adrian RatiuandChristian Brauner 41e8149c88 proc: add config & param to block forcing mem writes
This adds a Kconfig option and boot param to allow removing
the FOLL_FORCE flag from /proc/pid/mem write calls because
it can be abused.

The traditional forcing behavior is kept as default because
it can break GDB and some other use cases.

Previously we tried a more sophisticated approach allowing
distributions to fine-tune /proc/pid/mem behavior, however
that got NAK-ed by Linus [1], who prefers this simpler
approach with semantics also easier to understand for users.

Link: https://lore.kernel.org/lkml/CAHk-=wiGWLChxYmUA5HrT5aopZrB7_2VTa0NLZcxORgkUe5tEQ@mail.gmail.com/ [1]
Cc: Doug Anderson <dianders@chromium.org>
Cc: Jeff Xu <jeffxu@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Adrian Ratiu <adrian.ratiu@collabora.com>
Link: https://lore.kernel.org/r/20240802080225.89408-1-adrian.ratiu@collabora.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-08-30 08:19:43 +02:00
Deven BowersandPaul Moore 0311507792 lsm: add IPE lsm
Integrity Policy Enforcement (IPE) is an LSM that provides an
complimentary approach to Mandatory Access Control than existing LSMs
today.

Existing LSMs have centered around the concept of access to a resource
should be controlled by the current user's credentials. IPE's approach,
is that access to a resource should be controlled by the system's trust
of a current resource.

The basis of this approach is defining a global policy to specify which
resource can be trusted.

Signed-off-by: Deven Bowers <deven.desai@linux.microsoft.com>
Signed-off-by: Fan Wu <wufan@linux.microsoft.com>
[PM: subject line tweak]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2024-08-19 22:36:26 -04:00
Nathan ChancellorandAndrew Morton 7d354f49b8 fortify: drop Clang version check for 12.0.1 or newer
Now that the minimum supported version of LLVM for building the kernel has
been bumped to 13.0.1, this condition is always true, as the build will
fail during the configuration stage for older LLVM versions.  Remove it.

Link: https://lkml.kernel.org/r/20240125-bump-min-llvm-ver-to-13-0-1-v1-9-f5ff9bda41c5@kernel.org
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: "Aneesh Kumar K.V (IBM)" <aneesh.kumar@kernel.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Conor Dooley <conor@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Nicolas Schier <nicolas@fjasle.eu>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-22 15:38:54 -08:00
Nathan ChancellorandAndrew Morton 2947a4567f treewide: update LLVM Bugzilla links
LLVM moved their issue tracker from their own Bugzilla instance to GitHub
issues.  While all of the links are still valid, they may not necessarily
show the most up to date information around the issues, as all updates
will occur on GitHub, not Bugzilla.

Another complication is that the Bugzilla issue number is not always the
same as the GitHub issue number.  Thankfully, LLVM maintains this mapping
through two shortlinks:

  https://llvm.org/bz<num> -> https://bugs.llvm.org/show_bug.cgi?id=<num>
  https://llvm.org/pr<num> -> https://github.com/llvm/llvm-project/issues/<mapped_num>

Switch all "https://bugs.llvm.org/show_bug.cgi?id=<num>" links to the
"https://llvm.org/pr<num>" shortlink so that the links show the most up to
date information.  Each migrated issue links back to the Bugzilla entry,
so there should be no loss of fidelity of information here.

Link: https://lkml.kernel.org/r/20240109-update-llvm-links-v1-3-eb09b59db071@kernel.org
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Fangrui Song <maskray@google.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Mykola Lysenko <mykolal@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-22 15:38:51 -08:00
Vlastimil Babka d2e527f0d8 mm/slab: remove HAVE_HARDENED_USERCOPY_ALLOCATOR
With SLOB removed, both remaining allocators support hardened usercopy,
so remove the config and associated #ifdef.

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
2023-05-24 15:38:17 +02:00
Linus Torvalds c23f28975a Merge tag 'docs-6.4' of git://git.lwn.net/linux
Pull documentation updates from Jonathan Corbet:
 "Commit volume in documentation is relatively low this time, but there
  is still a fair amount going on, including:

   - Reorganize the architecture-specific documentation under
     Documentation/arch

     This makes the structure match the source directory and helps to
     clean up the mess that is the top-level Documentation directory a
     bit. This work creates the new directory and moves x86 and most of
     the less-active architectures there.

     The current plan is to move the rest of the architectures in 6.5,
     with the patches going through the appropriate subsystem trees.

   - Some more Spanish translations and maintenance of the Italian
     translation

   - A new "Kernel contribution maturity model" document from Ted

   - A new tutorial on quickly building a trimmed kernel from Thorsten

  Plus the usual set of updates and fixes"

* tag 'docs-6.4' of git://git.lwn.net/linux: (47 commits)
  media: Adjust column width for pdfdocs
  media: Fix building pdfdocs
  docs: clk: add documentation to log which clocks have been disabled
  docs: trace: Fix typo in ftrace.rst
  Documentation/process: always CC responsible lists
  docs: kmemleak: adjust to config renaming
  ELF: document some de-facto PT_* ABI quirks
  Documentation: arm: remove stih415/stih416 related entries
  docs: turn off "smart quotes" in the HTML build
  Documentation: firmware: Clarify firmware path usage
  docs/mm: Physical Memory: Fix grammar
  Documentation: Add document for false sharing
  dma-api-howto: typo fix
  docs: move m68k architecture documentation under Documentation/arch/
  docs: move parisc documentation under Documentation/arch/
  docs: move ia64 architecture docs under Documentation/arch/
  docs: Move arc architecture docs under Documentation/arch/
  docs: move nios2 documentation under Documentation/arch/
  docs: move openrisc documentation under Documentation/arch/
  docs: move superh documentation under Documentation/arch/
  ...
2023-04-24 12:35:49 -07:00
Linus Torvalds 08e30833f8 Merge tag 'lsm-pr-20230420' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm
Pull lsm updates from Paul Moore:

 - Move the LSM hook comment blocks into security/security.c

   For many years the LSM hook comment blocks were located in a very odd
   place, include/linux/lsm_hooks.h, where they lived on their own,
   disconnected from both the function prototypes and definitions.

   In keeping with current kernel conventions, this moves all of these
   comment blocks to the top of the function definitions, transforming
   them into the kdoc format in the process. This should make it much
   easier to maintain these comments, which are the main source of LSM
   hook documentation.

   For the most part the comment contents were left as-is, although some
   glaring errors were corrected. Expect additional edits in the future
   as we slowly update and correct the comment blocks.

   This is the bulk of the diffstat.

 - Introduce LSM_ORDER_LAST

   Similar to how LSM_ORDER_FIRST is used to specify LSMs which should
   be ordered before "normal" LSMs, the LSM_ORDER_LAST is used to
   specify LSMs which should be ordered after "normal" LSMs.

   This is one of the prerequisites for transitioning IMA/EVM to a
   proper LSM.

 - Remove the security_old_inode_init_security() hook

   The security_old_inode_init_security() LSM hook only allows for a
   single xattr which is problematic both for LSM stacking and the
   IMA/EVM-as-a-LSM effort. This finishes the conversion over to the
   security_inode_init_security() hook and removes the single-xattr LSM
   hook.

 - Fix a reiserfs problem with security xattrs

   During the security_old_inode_init_security() removal work it became
   clear that reiserfs wasn't handling security xattrs properly so we
   fixed it.

* tag 'lsm-pr-20230420' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm: (32 commits)
  reiserfs: Add security prefix to xattr name in reiserfs_security_write()
  security: Remove security_old_inode_init_security()
  ocfs2: Switch to security_inode_init_security()
  reiserfs: Switch to security_inode_init_security()
  security: Remove integrity from the LSM list in Kconfig
  Revert "integrity: double check iint_cache was initialized"
  security: Introduce LSM_ORDER_LAST and set it for the integrity LSM
  device_cgroup: Fix typo in devcgroup_css_alloc description
  lsm: fix a badly named parameter in security_get_getsecurity()
  lsm: fix doc warnings in the LSM hook comments
  lsm: styling fixes to security/security.c
  lsm: move the remaining LSM hook comments to security/security.c
  lsm: move the io_uring hook comments to security/security.c
  lsm: move the perf hook comments to security/security.c
  lsm: move the bpf hook comments to security/security.c
  lsm: move the audit hook comments to security/security.c
  lsm: move the binder hook comments to security/security.c
  lsm: move the sysv hook comments to security/security.c
  lsm: move the key hook comments to security/security.c
  lsm: move the xfrm hook comments to security/security.c
  ...
2023-04-24 11:21:50 -07:00
Jonathan Corbet ff61f0791c docs: move x86 documentation into Documentation/arch/
Move the x86 documentation under Documentation/arch/ as a way of cleaning
up the top-level directory and making the structure of our docs more
closely match the structure of the source directories it describes.

All in-kernel references to the old paths have been updated.

Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: linux-arch@vger.kernel.org
Cc: x86@kernel.org
Cc: Borislav Petkov <bp@alien8.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/lkml/20230315211523.108836-1-corbet@lwn.net/
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2023-03-30 12:58:51 -06:00
Paul Moore f22f9aaf6c selinux: remove the runtime disable functionality
After working with the larger SELinux-based distros for several
years, we're finally at a place where we can disable the SELinux
runtime disable functionality.  The existing kernel deprecation
notice explains the functionality and why we want to remove it:

  The selinuxfs "disable" node allows SELinux to be disabled at
  runtime prior to a policy being loaded into the kernel.  If
  disabled via this mechanism, SELinux will remain disabled until
  the system is rebooted.

  The preferred method of disabling SELinux is via the "selinux=0"
  boot parameter, but the selinuxfs "disable" node was created to
  make it easier for systems with primitive bootloaders that did not
  allow for easy modification of the kernel command line.
  Unfortunately, allowing for SELinux to be disabled at runtime makes
  it difficult to secure the kernel's LSM hooks using the
  "__ro_after_init" feature.

It is that last sentence, mentioning the '__ro_after_init' hardening,
which is the real motivation for this change, and if you look at the
diffstat you'll see that the impact of this patch reaches across all
the different LSMs, helping prevent tampering at the LSM hook level.

From a SELinux perspective, it is important to note that if you
continue to disable SELinux via "/etc/selinux/config" it may appear
that SELinux is disabled, but it is simply in an uninitialized state.
If you load a policy with `load_policy -i`, you will see SELinux
come alive just as if you had loaded the policy during early-boot.

It is also worth noting that the "/sys/fs/selinux/disable" file is
always writable now, regardless of the Kconfig settings, but writing
to the file has no effect on the system, other than to display an
error on the console if a non-zero/true value is written.

Finally, in the several years where we have been working on
deprecating this functionality, there has only been one instance of
someone mentioning any user visible breakage.  In this particular
case it was an individual's kernel test system, and the workaround
documented in the deprecation notice ("selinux=0" on the kernel
command line) resolved the issue without problem.

Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2023-03-20 12:34:23 -04:00
Roberto SassuandPaul Moore b9b8701b43 security: Remove integrity from the LSM list in Kconfig
Remove 'integrity' from the list of LSMs in Kconfig, as it is no longer
necessary. Since the recent change (set order to LSM_ORDER_LAST), the
'integrity' LSM is always enabled (if selected in the kernel
configuration).

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Acked-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2023-03-10 18:34:33 -05:00
Peter ZijlstraandBorislav Petkov f43b9876e8 x86/retbleed: Add fine grained Kconfig knobs
Do fine-grained Kconfig for all the various retbleed parts.

NOTE: if your compiler doesn't support return thunks this will
silently 'upgrade' your mitigation to IBPB, you might not like this.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
2022-06-29 17:43:41 +02:00
Matthew Wilcox (Oracle)andKees Cook 1109a5d907 usercopy: Remove HARDENED_USERCOPY_PAGESPAN
There isn't enough information to make this a useful check any more;
the useful parts of it were moved in earlier patches, so remove this
set of checks now.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Kees Cook <keescook@chromium.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220110231530.665970-5-willy@infradead.org
2022-04-13 12:15:52 -07:00
Linus Torvalds f87cbd0565 Merge tag 'hardening-v5.18-rc1-fix1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull hardening updates from Kees Cook:
 "This addresses an -Warray-bounds warning found under a few ARM
  defconfigs, and disables long-broken HARDENED_USERCOPY_PAGESPAN"

* tag 'hardening-v5.18-rc1-fix1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  ARM/dma-mapping: Remove CMA code when not built with CMA
  usercopy: Disable CONFIG_HARDENED_USERCOPY_PAGESPAN
2022-03-31 11:43:01 -07:00
Kees Cook ef3e787c21 usercopy: Disable CONFIG_HARDENED_USERCOPY_PAGESPAN
CONFIG_HARDENED_USERCOPY_PAGESPAN has been mostly broken for a while,
and it has become hard to ignore with some recent scsi changes[1].
While there is a more complete series to replace it with better checks[2],
it should have more soak time in -next. Instead, disable the config now,
with the expectation that it will be fully replaced in the next kernel
release.

[1] https://lore.kernel.org/lkml/20220324064846.GA12961@lst.de/
[2] https://lore.kernel.org/linux-hardening/20220110231530.665970-1-willy@infradead.org/

Suggested-by: Christoph Hellwig <hch@lst.de>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
2022-03-24 15:57:25 -07:00
Kees Cook 281d0c9627 fortify: Add Clang support
Enable FORTIFY_SOURCE support for Clang:

Use the new __pass_object_size and __overloadable attributes so that
Clang will have appropriate visibility into argument sizes such that
__builtin_object_size(p, 1) will behave correctly. Additional details
available here:
    https://github.com/llvm/llvm-project/issues/53516
    https://github.com/ClangBuiltLinux/linux/issues/1401

A bug with __builtin_constant_p() of globally defined variables was
fixed in Clang 13 (and backported to 12.0.1), so FORTIFY support must
depend on that version or later. Additional details here:
    https://bugs.llvm.org/show_bug.cgi?id=41459
    commit a52f8a59ae ("fortify: Explicitly disable Clang support")

A bug with Clang's -mregparm=3 and -m32 makes some builtins unusable,
so removing -ffreestanding (to gain the needed libcall optimizations
with Clang) cannot be done. Without the libcall optimizations, Clang
cannot provide appropriate FORTIFY coverage, so it must be disabled
for CONFIG_X86_32. Additional details here;
    https://github.com/llvm/llvm-project/issues/53645

Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: George Burgess IV <gbiv@google.com>
Cc: llvm@lists.linux.dev
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/r/20220208225350.1331628-9-keescook@chromium.org
2022-02-13 16:50:07 -08:00
Linus Torvalds 512b7931ad Merge branch 'akpm' (patches from Andrew)
Merge misc updates from Andrew Morton:
 "257 patches.

  Subsystems affected by this patch series: scripts, ocfs2, vfs, and
  mm (slab-generic, slab, slub, kconfig, dax, kasan, debug, pagecache,
  gup, swap, memcg, pagemap, mprotect, mremap, iomap, tracing, vmalloc,
  pagealloc, memory-failure, hugetlb, userfaultfd, vmscan, tools,
  memblock, oom-kill, hugetlbfs, migration, thp, readahead, nommu, ksm,
  vmstat, madvise, memory-hotplug, rmap, zsmalloc, highmem, zram,
  cleanups, kfence, and damon)"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (257 commits)
  mm/damon: remove return value from before_terminate callback
  mm/damon: fix a few spelling mistakes in comments and a pr_debug message
  mm/damon: simplify stop mechanism
  Docs/admin-guide/mm/pagemap: wordsmith page flags descriptions
  Docs/admin-guide/mm/damon/start: simplify the content
  Docs/admin-guide/mm/damon/start: fix a wrong link
  Docs/admin-guide/mm/damon/start: fix wrong example commands
  mm/damon/dbgfs: add adaptive_targets list check before enable monitor_on
  mm/damon: remove unnecessary variable initialization
  Documentation/admin-guide/mm/damon: add a document for DAMON_RECLAIM
  mm/damon: introduce DAMON-based Reclamation (DAMON_RECLAIM)
  selftests/damon: support watermarks
  mm/damon/dbgfs: support watermarks
  mm/damon/schemes: activate schemes based on a watermarks mechanism
  tools/selftests/damon: update for regions prioritization of schemes
  mm/damon/dbgfs: support prioritization weights
  mm/damon/vaddr,paddr: support pageout prioritization
  mm/damon/schemes: prioritize regions within the quotas
  mm/damon/selftests: support schemes quotas
  mm/damon/dbgfs: support quotas of schemes
  ...
2021-11-06 14:08:17 -07:00
Stephen KittandLinus Torvalds 53944f171a mm: remove HARDENED_USERCOPY_FALLBACK
This has served its purpose and is no longer used.  All usercopy
violations appear to have been handled by now, any remaining instances
(or new bugs) will cause copies to be rejected.

This isn't a direct revert of commit 2d891fbc3b ("usercopy: Allow
strict enforcement of whitelists"); since usercopy_fallback is
effectively 0, the fallback handling is removed too.

This also removes the usercopy_fallback module parameter on slab_common.

Link: https://github.com/KSPP/linux/issues/153
Link: https://lkml.kernel.org/r/20210921061149.1091163-1-steve@sk2.org
Signed-off-by: Stephen Kitt <steve@sk2.org>
Suggested-by: Kees Cook <keescook@chromium.org>
Acked-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>	[defconfig change]
Acked-by: David Rientjes <rientjes@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: James Morris <jmorris@namei.org>
Cc: "Serge E . Hallyn" <serge@hallyn.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:43 -07:00