linux/security, branch v6.0

Merge tag 'landlock-6.0-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/mic/linux

2022-09-02T22:24:08Z

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

landlock: Fix file reparenting without explicit LANDLOCK_ACCESS_FS_REFER

2022-09-02T13:29:08Z

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 b91c3e4ea756 ("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: b91c3e4ea756 ("landlock: Add support for file reparenting with LANDLOCK_ACCESS_FS_REFER") Reviewed-by: Paul Moore Reviewed-by: Günther Noack 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

Merge tag 'lsm-pr-20220829' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm

2022-08-31T16:23:16Z

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

Smack: Provide read control for io_uring_cmd

2022-08-26T18:56:35Z

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: ee692a21e9bf ("fs,io_uring: add infrastructure for uring-cmd") Signed-off-by: Casey Schaufler Signed-off-by: Paul Moore

selinux: implement the security_uring_cmd() LSM hook

2022-08-26T15:19:43Z

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 :io_uring { cmd }; Cc: stable@vger.kernel.org Fixes: ee692a21e9bf ("fs,io_uring: add infrastructure for uring-cmd") Signed-off-by: Paul Moore

lsm,io_uring: add LSM hooks for the new uring_cmd file op

2022-08-26T15:19:43Z

io-uring cmd support was added through ee692a21e9bf ("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: ee692a21e9bf ("fs,io_uring: add infrastructure for uring-cmd") Signed-off-by: Luis Chamberlain Acked-by: Jens Axboe Signed-off-by: Paul Moore

Merge tag 'hardening-v6.0-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

2022-08-19T20:56:14Z

Pull hardening fixes from Kees Cook: - Also undef LATENT_ENTROPY_PLUGIN for per-file disabling (Andrew Donnellan) - Return EFAULT on copy_from_user() failures in LoadPin (Kees Cook) * tag 'hardening-v6.0-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: gcc-plugins: Undefine LATENT_ENTROPY_PLUGIN when plugin disabled for a file LoadPin: Return EFAULT on copy_from_user() failures

LoadPin: Return EFAULT on copy_from_user() failures

2022-08-16T19:17:18Z

The copy_from_user() function returns the number of bytes remaining to be copied on a failure. Such failures should return -EFAULT to high levels. Reported-by: kernel test robot Reported-by: Dan Carpenter Fixes: 3f805f8cc23b ("LoadPin: Enable loading from trusted dm-verity devices") Cc: Matthias Kaehlcke Cc: James Morris Cc: "Serge E. Hallyn" Cc: linux-security-module@vger.kernel.org Signed-off-by: Kees Cook

Merge tag 'apparmor-pr-2022-08-08' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor

2022-08-10T17:53:22Z

Pull AppArmor updates from John Johansen: "This is mostly cleanups and bug fixes with the one bigger change being Mathew Wilcox's patch to use XArrays instead of the IDR from the thread around the locking weirdness. Features: - Convert secid mapping to XArrays instead of IDR - Add a kernel label to use on kernel objects - Extend policydb permission set by making use of the xbits - Make export of raw binary profile to userspace optional - Enable tuning of policy paranoid load for embedded systems - Don't create raw_sha1 symlink if sha1 hashing is disabled - Allow labels to carry debug flags Cleanups: - Update MAINTAINERS file - Use struct_size() helper in kmalloc() - Move ptrace mediation to more logical task.{h,c} - Resolve uninitialized symbol warnings - Remove redundant ret variable - Mark alloc_unconfined() as static - Update help description of policy hash for introspection - Remove some casts which are no-longer required Bug Fixes: - Fix aa_label_asxprint return check - Fix reference count leak in aa_pivotroot() - Fix memleak in aa_simple_write_to_buffer() - Fix kernel doc comments - Fix absroot causing audited secids to begin with = - Fix quiet_denied for file rules - Fix failed mount permission check error message - Disable showing the mode as part of a secid to secctx - Fix setting unconfined mode on a loaded profile - Fix overlapping attachment computation - Fix undefined reference to `zlib_deflate_workspacesize'" * tag 'apparmor-pr-2022-08-08' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor: (34 commits) apparmor: Update MAINTAINERS file with new email address apparmor: correct config reference to intended one apparmor: move ptrace mediation to more logical task.{h,c} apparmor: extend policydb permission set by making use of the xbits apparmor: allow label to carry debug flags apparmor: fix overlapping attachment computation apparmor: fix setting unconfined mode on a loaded profile apparmor: Fix some kernel-doc comments apparmor: Mark alloc_unconfined() as static apparmor: disable showing the mode as part of a secid to secctx apparmor: Convert secid mapping to XArrays instead of IDR apparmor: add a kernel label to use on kernel objects apparmor: test: Remove some casts which are no-longer required apparmor: Fix memleak in aa_simple_write_to_buffer() apparmor: fix reference count leak in aa_pivotroot() apparmor: Fix some kernel-doc comments apparmor: Fix undefined reference to `zlib_deflate_workspacesize' apparmor: fix aa_label_asxprint return check apparmor: Fix some kernel-doc comments apparmor: Fix some kernel-doc comments ...

Merge tag 'linux-kselftest-kunit-5.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

2022-08-03T02:34:45Z

Pull KUnit updates from Shuah Khan: "This consists of several fixes and an important feature to discourage running KUnit tests on production systems. Running tests on a production system could leave the system in a bad state. Summary: - Add a new taint type, TAINT_TEST to signal that a test has been run. This should discourage people from running these tests on production systems, and to make it easier to tell if tests have been run accidentally (by loading the wrong configuration, etc) - Several documentation and tool enhancements and fixes" * tag 'linux-kselftest-kunit-5.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: (29 commits) Documentation: KUnit: Fix example with compilation error Documentation: kunit: Add CLI args for kunit_tool kcsan: test: Add a .kunitconfig to run KCSAN tests kunit: executor: Fix a memory leak on failure in kunit_filter_tests clk: explicitly disable CONFIG_UML_PCI_OVER_VIRTIO in .kunitconfig mmc: sdhci-of-aspeed: test: Use kunit_test_suite() macro nitro_enclaves: test: Use kunit_test_suite() macro thunderbolt: test: Use kunit_test_suite() macro kunit: flatten kunit_suite*** to kunit_suite** in .kunit_test_suites kunit: unify module and builtin suite definitions selftest: Taint kernel when test module loaded module: panic: Taint the kernel when selftest modules load Documentation: kunit: fix example run_kunit func to allow spaces in args Documentation: kunit: Cleanup run_wrapper, fix x-ref kunit: test.h: fix a kernel-doc markup kunit: tool: Enable virtio/PCI by default on UML kunit: tool: make --kunitconfig repeatable, blindly concat kunit: add coverage_uml.config to enable GCOV on UML kunit: tool: refactor internal kconfig handling, allow overriding kunit: tool: introduce --qemu_args ...