Commit Graph

5343 Commits

Author SHA1 Message Date
Linus Torvalds 223b845253 Merge tag 'fs.acl.rework.prep.v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping
Pull vfs acl updates from Christian Brauner:
 "These are general fixes and preparatory changes related to the ongoing
  posix acl rework. The actual rework where we build a type safe posix
  acl api wasn't ready for this merge window but we're hopeful for the
  next merge window.

  General fixes:

   - Some filesystems like 9p and cifs have to implement custom posix
     acl handlers because they require access to the dentry in order to
     set and get posix acls while the set and get inode operations
     currently don't. But the ntfs3 filesystem has no such requirement
     and thus implemented custom posix acl xattr handlers when it really
     didn't have to. So this pr contains patch that just implements set
     and get inode operations for ntfs3 and switches it to rely on the
     generic posix acl xattr handlers. (We would've appreciated reviews
     from the ntfs3 maintainers but we didn't get any. But hey, if we
     really broke it we'll fix it. But fstests for ntfs3 said it's
     fine.)

   - The posix_acl_fix_xattr_common() helper has been adapted so it can
     be used by a few more callers and avoiding open-coding the same
     checks over and over.

  Other than the two general fixes this series introduces a new helper
  vfs_set_acl_prepare(). The reason for this helper is so that we can
  mitigate one of the source that change {g,u}id values directly in the
  uapi struct. With the vfs_set_acl_prepare() helper we can move the
  idmapped mount fixup into the generic posix acl set handler.

  The advantage of this is that it allows us to remove the
  posix_acl_setxattr_idmapped_mnt() helper which so far we had to call
  in vfs_setxattr() to account for idmapped mounts. While semantically
  correct the problem with this approach was that we had to keep the
  value parameter of the generic vfs_setxattr() call as non-const. This
  is rectified in this series.

  Ultimately, we will get rid of all the extreme kludges and type
  unsafety once we have merged the posix api - hopefully during the next
  merge window - built solely around get and set inode operations. Which
  incidentally will also improve handling of posix acls in security and
  especially in integrity modesl. While this will come with temporarily
  having two inode operation for posix acls that is nothing compared to
  the problems we have right now and so well worth it. We'll end up with
  something that we can actually reason about instead of needing to
  write novels to explain what's going on"

* tag 'fs.acl.rework.prep.v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping:
  xattr: always us is_posix_acl_xattr() helper
  acl: fix the comments of posix_acl_xattr_set
  xattr: constify value argument in vfs_setxattr()
  ovl: use vfs_set_acl_prepare()
  acl: move idmapping handling into posix_acl_xattr_set()
  acl: add vfs_set_acl_prepare()
  acl: return EOPNOTSUPP in posix_acl_fix_xattr_common()
  ntfs3: rework xattr handlers and switch to POSIX ACL VFS helpers
2022-10-03 19:48:54 -07:00
Linus Torvalds 26b84401da Merge tag 'lsm-pr-20221003' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm
Pull LSM updates from Paul Moore:
 "Seven patches for the LSM layer and we've got a mix of trivial and
  significant patches. Highlights below, starting with the smaller bits
  first so they don't get lost in the discussion of the larger items:

   - Remove some redundant NULL pointer checks in the common LSM audit
     code.

   - Ratelimit the lockdown LSM's access denial messages.

     With this change there is a chance that the last visible lockdown
     message on the console is outdated/old, but it does help preserve
     the initial series of lockdown denials that started the denial
     message flood and my gut feeling is that these might be the more
     valuable messages.

   - Open userfaultfds as readonly instead of read/write.

     While this code obviously lives outside the LSM, it does have a
     noticeable impact on the LSMs with Ondrej explaining the situation
     in the commit description. It is worth noting that this patch
     languished on the VFS list for over a year without any comments
     (objections or otherwise) so I took the liberty of pulling it into
     the LSM tree after giving fair notice. It has been in linux-next
     since the end of August without any noticeable problems.

   - Add a LSM hook for user namespace creation, with implementations
     for both the BPF LSM and SELinux.

     Even though the changes are fairly small, this is the bulk of the
     diffstat as we are also including BPF LSM selftests for the new
     hook.

     It's also the most contentious of the changes in this pull request
     with Eric Biederman NACK'ing the LSM hook multiple times during its
     development and discussion upstream. While I've never taken NACK's
     lightly, I'm sending these patches to you because it is my belief
     that they are of good quality, satisfy a long-standing need of
     users and distros, and are in keeping with the existing nature of
     the LSM layer and the Linux Kernel as a whole.

     The patches in implement a LSM hook for user namespace creation
     that allows for a granular approach, configurable at runtime, which
     enables both monitoring and control of user namespaces. The general
     consensus has been that this is far preferable to the other
     solutions that have been adopted downstream including outright
     removal from the kernel, disabling via system wide sysctls, or
     various other out-of-tree mechanisms that users have been forced to
     adopt since we haven't been able to provide them an upstream
     solution for their requests. Eric has been steadfast in his
     objections to this LSM hook, explaining that any restrictions on
     the user namespace could have significant impact on userspace.
     While there is the possibility of impacting userspace, it is
     important to note that this solution only impacts userspace when it
     is requested based on the runtime configuration supplied by the
     distro/admin/user. Frederick (the pathset author), the LSM/security
     community, and myself have tried to work with Eric during
     development of this patchset to find a mutually acceptable
     solution, but Eric's approach and unwillingness to engage in a
     meaningful way have made this impossible. I have CC'd Eric directly
     on this pull request so he has a chance to provide his side of the
     story; there have been no objections outside of Eric's"

* tag 'lsm-pr-20221003' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm:
  lockdown: ratelimit denial messages
  userfaultfd: open userfaultfds with O_RDONLY
  selinux: Implement userns_create hook
  selftests/bpf: Add tests verifying bpf lsm userns_create hook
  bpf-lsm: Make bpf_lsm_userns_create() sleepable
  security, lsm: Introduce security_create_user_ns()
  lsm: clean up redundant NULL pointer check
2022-10-03 17:51:52 -07:00
Linus Torvalds e816da29bc Merge tag 'selinux-pr-20221003' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux
Pull SELinux updates from Paul Moore:
 "Six SELinux patches, all are simple and easily understood, but a list
  of the highlights is below:

   - Use 'grep -E' instead of 'egrep' in the SELinux policy install
     script.

     Fun fact, this seems to be GregKH's *second* dedicated SELinux
     patch since we transitioned to git (ignoring merges, the SPDX
     stuff, and a trivial fs reference removal when lustre was yanked);
     the first was back in 2011 when selinuxfs was placed in
     /sys/fs/selinux. Oh, the memories ...

   - Convert the SELinux policy boolean values to use signed integer
     types throughout the SELinux kernel code.

     Prior to this we were using a mix of signed and unsigned integers
     which was probably okay in this particular case, but it is
     definitely not a good idea in general.

   - Remove a reference to the SELinux runtime disable functionality in
     /etc/selinux/config as we are in the process of deprecating that.

     See [1] for more background on this if you missed the previous
     notes on the deprecation.

   - Minor cleanups: remove unneeded variables and function parameter
     constification"

Link: https://github.com/SELinuxProject/selinux-kernel/wiki/DEPRECATE-runtime-disable [1]

* tag 'selinux-pr-20221003' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
  selinux: remove runtime disable message in the install_policy.sh script
  selinux: use "grep -E" instead of "egrep"
  selinux: remove the unneeded result variable
  selinux: declare read-only parameters const
  selinux: use int arrays for boolean values
  selinux: remove an unneeded variable in sel_make_class_dir_entries()
2022-10-03 17:45:15 -07:00
Linus Torvalds eafb121ec0 Merge tag 'integrity-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity
Pull integrity updates from Mimi Zohar:
 "Just two bug fixes"

* tag 'integrity-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
  efi: Correct Macmini DMI match in uefi cert quirk
  ima: fix blocking of security.ima xattrs of unsupported algorithms
2022-10-03 17:42:12 -07:00
Linus Torvalds 74a0f84590 Merge tag 'Smack-for-6.1' of https://github.com/cschaufler/smack-next
Pull smack updates from Casey Schaufler:
 "Two minor code clean-ups: one removes constants left over from the old
  mount API, while the other gets rid of an unneeded variable.

  The other change fixes a flaw in handling IPv6 labeling"

* tag 'Smack-for-6.1' of https://github.com/cschaufler/smack-next:
  smack: cleanup obsolete mount option flags
  smack: lsm: remove the unneeded result variable
  SMACK: Add sk_clone_security LSM hook
2022-10-03 17:38:09 -07:00
Linus Torvalds d0989d01c6 Merge tag 'hardening-v6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull kernel hardening updates from Kees Cook:
 "Most of the collected changes here are fixes across the tree for
  various hardening features (details noted below).

  The most notable new feature here is the addition of the memcpy()
  overflow warning (under CONFIG_FORTIFY_SOURCE), which is the next step
  on the path to killing the common class of "trivially detectable"
  buffer overflow conditions (i.e. on arrays with sizes known at compile
  time) that have resulted in many exploitable vulnerabilities over the
  years (e.g. BleedingTooth).

  This feature is expected to still have some undiscovered false
  positives. It's been in -next for a full development cycle and all the
  reported false positives have been fixed in their respective trees.
  All the known-bad code patterns we could find with Coccinelle are also
  either fixed in their respective trees or in flight.

  The commit message in commit 54d9469bc5 ("fortify: Add run-time WARN
  for cross-field memcpy()") for the feature has extensive details, but
  I'll repeat here that this is a warning _only_, and is not intended to
  actually block overflows (yet). The many patches fixing array sizes
  and struct members have been landing for several years now, and we're
  finally able to turn this on to find any remaining stragglers.

  Summary:

  Various fixes across several hardening areas:

   - loadpin: Fix verity target enforcement (Matthias Kaehlcke).

   - zero-call-used-regs: Add missing clobbers in paravirt (Bill
     Wendling).

   - CFI: clean up sparc function pointer type mismatches (Bart Van
     Assche).

   - Clang: Adjust compiler flag detection for various Clang changes
     (Sami Tolvanen, Kees Cook).

   - fortify: Fix warnings in arch-specific code in sh, ARM, and xen.

  Improvements to existing features:

   - testing: improve overflow KUnit test, introduce fortify KUnit test,
     add more coverage to LKDTM tests (Bart Van Assche, Kees Cook).

   - overflow: Relax overflow type checking for wider utility.

  New features:

   - string: Introduce strtomem() and strtomem_pad() to fill a gap in
     strncpy() replacement needs.

   - um: Enable FORTIFY_SOURCE support.

   - fortify: Enable run-time struct member memcpy() overflow warning"

* tag 'hardening-v6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (27 commits)
  Makefile.extrawarn: Move -Wcast-function-type-strict to W=1
  hardening: Remove Clang's enable flag for -ftrivial-auto-var-init=zero
  sparc: Unbreak the build
  x86/paravirt: add extra clobbers with ZERO_CALL_USED_REGS enabled
  x86/paravirt: clean up typos and grammaros
  fortify: Convert to struct vs member helpers
  fortify: Explicitly check bounds are compile-time constants
  x86/entry: Work around Clang __bdos() bug
  ARM: decompressor: Include .data.rel.ro.local
  fortify: Adjust KUnit test for modular build
  sh: machvec: Use char[] for section boundaries
  kunit/memcpy: Avoid pathological compile-time string size
  lib: Improve the is_signed_type() kunit test
  LoadPin: Require file with verity root digests to have a header
  dm: verity-loadpin: Only trust verity targets with enforcement
  LoadPin: Fix Kconfig doc about format of file with verity digests
  um: Enable FORTIFY_SOURCE
  lkdtm: Update tests for memcpy() run-time warnings
  fortify: Add run-time WARN for cross-field memcpy()
  fortify: Use SIZE_MAX instead of (size_t)-1
  ...
2022-10-03 17:24:22 -07:00
Orlando Chamberlain bab715bdaa efi: Correct Macmini DMI match in uefi cert quirk
It turns out Apple doesn't capitalise the "mini" in "Macmini" in DMI, which
is inconsistent with other model line names.

Correct the capitalisation of Macmini in the quirk for skipping loading
platform certs on T2 Macs.

Currently users get:

------------[ cut here ]------------
[Firmware Bug]: Page fault caused by firmware at PA: 0xffffa30640054000
WARNING: CPU: 1 PID: 8 at arch/x86/platform/efi/quirks.c:735 efi_crash_gracefully_on_page_fault+0x55/0xe0
Modules linked in:
CPU: 1 PID: 8 Comm: kworker/u12:0 Not tainted 5.18.14-arch1-2-t2 #1 4535eb3fc40fd08edab32a509fbf4c9bc52d111e
Hardware name: Apple Inc. Macmini8,1/Mac-7BA5B2DFE22DDD8C, BIOS 1731.120.10.0.0 (iBridge: 19.16.15071.0.0,0) 04/24/2022
Workqueue: efi_rts_wq efi_call_rts
...
---[ end trace 0000000000000000 ]---
efi: Froze efi_rts_wq and disabled EFI Runtime Services
integrity: Couldn't get size: 0x8000000000000015
integrity: MODSIGN: Couldn't get UEFI db list
efi: EFI Runtime Services are disabled!
integrity: Couldn't get size: 0x8000000000000015
integrity: Couldn't get UEFI dbx list

Fixes: 155ca952c7 ("efi: Do not import certificates from UEFI Secure Boot for T2 Macs")
Cc: stable@vger.kernel.org
Cc: Aditya Garg <gargaditya08@live.com>
Tested-by: Samuel Jiang <chyishian.jiang@gmail.com>
Signed-off-by: Orlando Chamberlain <redecorating@protonmail.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2022-09-30 13:47:27 -04:00
Kees Cook 607e57c6c6 hardening: Remove Clang's enable flag for -ftrivial-auto-var-init=zero
Now that Clang's -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang
option is no longer required, remove it from the command line. Clang 16
and later will warn when it is used, which will cause Kconfig to think
it can't use -ftrivial-auto-var-init=zero at all. Check for whether it
is required and only use it when so.

Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: linux-kbuild@vger.kernel.org
Cc: llvm@lists.linux.dev
Cc: stable@vger.kernel.org
Fixes: f02003c860 ("hardening: Avoid harmless Clang option under CONFIG_INIT_STACK_ALL_ZERO")
Signed-off-by: Kees Cook <keescook@chromium.org>
2022-09-29 23:05:00 -07:00
Xiu Jianfeng cc71271f5b smack: cleanup obsolete mount option flags
These mount option flags are obsolete since commit 12085b14a4 ("smack:
switch to private smack_mnt_opts"), remove them.

Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2022-09-27 10:33:03 -07:00
Xu Panda d3f84f5c96 smack: lsm: remove the unneeded result variable
Return the value smk_ptrace_rule_check() directly instead of storing it
in another redundant variable.

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Xu Panda <xu.panda@zte.com.cn>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2022-09-27 10:33:03 -07:00
Lontke Michael 4ca165fc6c SMACK: Add sk_clone_security LSM hook
Using smk_of_current() during sk_alloc_security hook leads in
rare cases to a faulty initialization of the security context
of the created socket.

By adding the LSM hook sk_clone_security to SMACK this initialization
fault is corrected by copying the security context of the old socket
pointer to the newly cloned one.

Co-authored-by: Martin Ostertag: <martin.ostertag@elektrobit.com>
Signed-off-by: Lontke Michael <michael.lontke@elektrobit.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2022-09-27 10:33:03 -07:00
Xu Panda 09b71adab0 selinux: remove the unneeded result variable
Return the value avc_has_perm() directly instead of storing it in
another redundant variable.

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Xu Panda <xu.panda@zte.com.cn>
[PM: subject line tweak]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2022-09-14 07:47:27 -04:00
Nathan Lynch 1e7d8bcbe3 lockdown: ratelimit denial messages
User space can flood the log with lockdown denial messages:

[  662.555584] Lockdown: bash: debugfs access is restricted; see man kernel_lockdown.7
[  662.563237] Lockdown: bash: debugfs access is restricted; see man kernel_lockdown.7
[  662.571134] Lockdown: bash: debugfs access is restricted; see man kernel_lockdown.7
[  662.578668] Lockdown: bash: debugfs access is restricted; see man kernel_lockdown.7
[  662.586021] Lockdown: bash: debugfs access is restricted; see man kernel_lockdown.7
[  662.593398] Lockdown: bash: debugfs access is restricted; see man kernel_lockdown.7

Ratelimiting these shouldn't meaningfully degrade the quality of the
information logged.

Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2022-09-14 07:37:50 -04:00
Matthias Kaehlcke 6e42aec7c7 LoadPin: Require file with verity root digests to have a header
LoadPin expects the file with trusted verity root digests to be
an ASCII file with one digest (hex value) per line. A pinned
root could contain files that meet these format requirements,
even though the hex values don't represent trusted root
digests.

Add a new requirement to the file format which consists in
the first line containing a fixed string. This prevents
attackers from feeding files with an otherwise valid format
to LoadPin.

Suggested-by: Sarthak Kukreti <sarthakkukreti@chromium.org>
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220906181725.1.I3f51d1bb0014e5a5951be4ad3c5ad7c7ca1dfc32@changeid
2022-09-07 16:37:27 -07:00
Matthias Kaehlcke aafc203bba LoadPin: Fix Kconfig doc about format of file with verity digests
The doc for CONFIG_SECURITY_LOADPIN_VERITY says that the file with verity
digests must contain a comma separated list of digests. That was the case
at some stage of the development, but was changed during the review
process to one digest per line. Update the Kconfig doc accordingly.

Reported-by: Jae Hoon Kim <kimjae@chromium.org>
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Fixes: 3f805f8cc2 ("LoadPin: Enable loading from trusted dm-verity devices")
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220829174557.1.I5d202d1344212a3800d9828f936df6511eb2d0d1@changeid
2022-09-07 16:37:27 -07:00
Linus Torvalds 0c95f02269 Merge tag 'landlock-6.0-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/mic/linux
Pull landlock fix from Mickaël Salaün:
 "This fixes a mis-handling of the LANDLOCK_ACCESS_FS_REFER right when
  multiple rulesets/domains are stacked.

  The expected behaviour was that an additional ruleset can only
  restrict the set of permitted operations, but in this particular case,
  it was potentially possible to re-gain the LANDLOCK_ACCESS_FS_REFER
  right"

* tag 'landlock-6.0-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/mic/linux:
  landlock: Fix file reparenting without explicit LANDLOCK_ACCESS_FS_REFER
2022-09-02 15:24:08 -07:00
Mickaël Salaün 55e55920bb landlock: Fix file reparenting without explicit LANDLOCK_ACCESS_FS_REFER
This change fixes a mis-handling of the LANDLOCK_ACCESS_FS_REFER right
when multiple rulesets/domains are stacked. The expected behaviour was
that an additional ruleset can only restrict the set of permitted
operations, but in this particular case, it was potentially possible to
re-gain the LANDLOCK_ACCESS_FS_REFER right.

With the introduction of LANDLOCK_ACCESS_FS_REFER, we added the first
globally denied-by-default access right.  Indeed, this lifted an initial
Landlock limitation to rename and link files, which was initially always
denied when the source or the destination were different directories.

This led to an inconsistent backward compatibility behavior which was
only taken into account if no domain layer were using the new
LANDLOCK_ACCESS_FS_REFER right. However, when restricting a thread with
a new ruleset handling LANDLOCK_ACCESS_FS_REFER, all inherited parent
rulesets/layers not explicitly handling LANDLOCK_ACCESS_FS_REFER would
behave as if they were handling this access right and with all their
rules allowing it. This means that renaming and linking files could
became allowed by these parent layers, but all the other required
accesses must also be granted: all layers must allow file removal or
creation, and renaming and linking operations cannot lead to privilege
escalation according to the Landlock policy.  See detailed explanation
in commit b91c3e4ea7 ("landlock: Add support for file reparenting with
LANDLOCK_ACCESS_FS_REFER").

To say it another way, this bug may lift the renaming and linking
limitations of the initial Landlock version, and a same ruleset can
enforce different restrictions depending on previous or next enforced
ruleset (i.e. inconsistent behavior). The LANDLOCK_ACCESS_FS_REFER right
cannot give access to data not already allowed, but this doesn't follow
the contract of the first Landlock ABI. This fix puts back the
limitation for sandboxes that didn't opt-in for this additional right.

For instance, if a first ruleset allows LANDLOCK_ACCESS_FS_MAKE_REG on
/dst and LANDLOCK_ACCESS_FS_REMOVE_FILE on /src, renaming /src/file to
/dst/file is denied. However, without this fix, stacking a new ruleset
which allows LANDLOCK_ACCESS_FS_REFER on / would now permit the
sandboxed thread to rename /src/file to /dst/file .

This change fixes the (absolute) rule access rights, which now always
forbid LANDLOCK_ACCESS_FS_REFER except when it is explicitly allowed
when creating a rule.

Making all domain handle LANDLOCK_ACCESS_FS_REFER was an initial
approach but there is two downsides:
* it makes the code more complex because we still want to check that a
  rule allowing LANDLOCK_ACCESS_FS_REFER is legitimate according to the
  ruleset's handled access rights (i.e. ABI v1 != ABI v2);
* it would not allow to identify if the user created a ruleset
  explicitly handling LANDLOCK_ACCESS_FS_REFER or not, which will be an
  issue to audit Landlock.

Instead, this change adds an ACCESS_INITIALLY_DENIED list of
denied-by-default rights, which (only) contains
LANDLOCK_ACCESS_FS_REFER.  All domains are treated as if they are also
handling this list, but without modifying their fs_access_masks field.

A side effect is that the errno code returned by rename(2) or link(2)
*may* be changed from EXDEV to EACCES according to the enforced
restrictions.  Indeed, we now have the mechanic to identify if an access
is denied because of a required right (e.g. LANDLOCK_ACCESS_FS_MAKE_REG,
LANDLOCK_ACCESS_FS_REMOVE_FILE) or if it is denied because of missing
LANDLOCK_ACCESS_FS_REFER rights.  This may result in different errno
codes than for the initial Landlock version, but this approach is more
consistent and better for rename/link compatibility reasons, and it
wasn't possible before (hence no backport to ABI v1).  The
layout1.rename_file test reflects this change.

Add 4 layout1.refer_denied_by_default* test suites to check that the
behavior of a ruleset not handling LANDLOCK_ACCESS_FS_REFER (ABI v1) is
unchanged even if another layer handles LANDLOCK_ACCESS_FS_REFER (i.e.
ABI v1 precedence).  Make sure rule's absolute access rights are correct
by testing with and without a matching path.  Add test_rename() and
test_exchange() helpers.

Extend layout1.inval tests to check that a denied-by-default access
right is not necessarily part of a domain's handled access rights.

Test coverage for security/landlock is 95.3% of 599 lines according to
gcc/gcov-11.

Fixes: b91c3e4ea7 ("landlock: Add support for file reparenting with LANDLOCK_ACCESS_FS_REFER")
Reviewed-by: Paul Moore <paul@paul-moore.com>
Reviewed-by: Günther Noack <gnoack3000@gmail.com>
Link: https://lore.kernel.org/r/20220831203840.1370732-1-mic@digikod.net
Cc: stable@vger.kernel.org
[mic: Constify and slightly simplify test helpers]
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2022-09-02 15:29:08 +02:00
Linus Torvalds 9c9d1896fa Merge tag 'lsm-pr-20220829' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm
Pull LSM support for IORING_OP_URING_CMD from Paul Moore:
 "Add SELinux and Smack controls to the io_uring IORING_OP_URING_CMD.

  These are necessary as without them the IORING_OP_URING_CMD remains
  outside the purview of the LSMs (Luis' LSM patch, Casey's Smack patch,
  and my SELinux patch). They have been discussed at length with the
  io_uring folks, and Jens has given his thumbs-up on the relevant
  patches (see the commit descriptions).

  There is one patch that is not strictly necessary, but it makes
  testing much easier and is very trivial: the /dev/null
  IORING_OP_URING_CMD patch."

* tag 'lsm-pr-20220829' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm:
  Smack: Provide read control for io_uring_cmd
  /dev/null: add IORING_OP_URING_CMD support
  selinux: implement the security_uring_cmd() LSM hook
  lsm,io_uring: add LSM hooks for the new uring_cmd file op
2022-08-31 09:23:16 -07:00
Christian Brauner 52edb4080e acl: move idmapping handling into posix_acl_xattr_set()
The uapi POSIX ACL struct passed through the value argument during
setxattr() contains {g,u}id values encoded via ACL_{GROUP,USER} entries
that should actually be stored in the form of k{g,u}id_t (See [1] for a
long explanation of the issue.).

In 0c5fd887d2 ("acl: move idmapped mount fixup into vfs_{g,s}etxattr()")
we took the mount's idmapping into account in order to let overlayfs
handle POSIX ACLs on idmapped layers correctly. The fixup is currently
performed directly in vfs_setxattr() which piles on top of the earlier
hackiness by handling the mount's idmapping and stuff the vfs{g,u}id_t
values into the uapi struct as well. While that is all correct and works
fine it's just ugly.

Now that we have introduced vfs_make_posix_acl() earlier move handling
idmapped mounts out of vfs_setxattr() and into the POSIX ACL handler
where it belongs.

Note that we also need to call vfs_make_posix_acl() for EVM which
interpretes POSIX ACLs during security_inode_setxattr(). Leave them a
longer comment for future reference.

All filesystems that support idmapped mounts via FS_ALLOW_IDMAP use the
standard POSIX ACL xattr handlers and are covered by this change. This
includes overlayfs which simply calls vfs_{g,s}etxattr().

The following filesystems use custom POSIX ACL xattr handlers: 9p, cifs,
ecryptfs, and ntfs3 (and overlayfs but we've covered that in the paragraph
above) and none of them support idmapped mounts yet.

Link: https://lore.kernel.org/all/20220801145520.1532837-1-brauner@kernel.org/ [1]
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Reviewed-by: Seth Forshee (DigitalOcean) <sforshee@kernel.org>
2022-08-31 16:37:58 +02:00
Christian Göttsche 6354324d8a selinux: declare read-only parameters const
Declare ebitmap, mls_level and mls_context parameters const where they
are only read from.  This allows callers to supply pointers to const
as arguments and increases readability.

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2022-08-30 17:14:36 -04:00
Christian Göttsche c3fae2b2e6 selinux: use int arrays for boolean values
Do not cast pointers of signed integers to pointers of unsigned integers
and vice versa.

It should currently not be an issue since they hold SELinux boolean
values which should only contain either 0's or 1's, which should have
the same representation.

Reported by sparse:

  .../selinuxfs.c:1485:30: warning: incorrect type in assignment
                                    (different signedness)
  .../selinuxfs.c:1485:30:    expected unsigned int *
  .../selinuxfs.c:1485:30:    got int *[addressable] values
  .../selinuxfs.c:1402:48: warning: incorrect type in argument 3
                                    (different signedness)
  .../selinuxfs.c:1402:48:    expected int *values
  .../selinuxfs.c:1402:48:    got unsigned int *bool_pending_values

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
[PM: minor whitespace fixes, sparse output cleanup]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2022-08-30 17:03:33 -04:00
ye xingchen 5698f08169 selinux: remove an unneeded variable in sel_make_class_dir_entries()
Return the value sel_make_perm_files() directly instead of storing it
in another redundant variable.

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: ye xingchen <ye.xingchen@zte.com.cn>
[PM: subject line tweak]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2022-08-30 16:26:01 -04:00
Casey Schaufler dd93734022 Smack: Provide read control for io_uring_cmd
Limit io_uring "cmd" options to files for which the caller has
Smack read access. There may be cases where the cmd option may
be closer to a write access than a read, but there is no way
to make that determination.

Cc: stable@vger.kernel.org
Fixes: ee692a21e9 ("fs,io_uring: add infrastructure for uring-cmd")
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2022-08-26 14:56:35 -04:00
Paul Moore f4d653dcaa selinux: implement the security_uring_cmd() LSM hook
Add a SELinux access control for the iouring IORING_OP_URING_CMD
command.  This includes the addition of a new permission in the
existing "io_uring" object class: "cmd".  The subject of the new
permission check is the domain of the process requesting access, the
object is the open file which points to the device/file that is the
target of the IORING_OP_URING_CMD operation.  A sample policy rule
is shown below:

  allow <domain> <file>:io_uring { cmd };

Cc: stable@vger.kernel.org
Fixes: ee692a21e9 ("fs,io_uring: add infrastructure for uring-cmd")
Signed-off-by: Paul Moore <paul@paul-moore.com>
2022-08-26 11:19:43 -04:00
Luis Chamberlain 2a58401240 lsm,io_uring: add LSM hooks for the new uring_cmd file op
io-uring cmd support was added through ee692a21e9 ("fs,io_uring:
add infrastructure for uring-cmd"), this extended the struct
file_operations to allow a new command which each subsystem can use
to enable command passthrough. Add an LSM specific for the command
passthrough which enables LSMs to inspect the command details.

This was discussed long ago without no clear pointer for something
conclusive, so this enables LSMs to at least reject this new file
operation.

[0] https://lkml.kernel.org/r/8adf55db-7bab-f59d-d612-ed906b948d19@schaufler-ca.com

Cc: stable@vger.kernel.org
Fixes: ee692a21e9 ("fs,io_uring: add infrastructure for uring-cmd")
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Acked-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2022-08-26 11:19:43 -04:00