selftests/bpf: Reject graph kptr use after RCU unlockgrafted

Add a sleepable verifier test that loads a graph-node local kptr in an
explicit RCU read-side critical section, then passes its node to
bpf_rbtree_remove() after the section ends.

Before the verifier fix, the stale NON_OWN_REF flag makes the node look like
a live borrowed reference and the program is accepted. After the fix, the
pointer is demoted without NON_OWN_REF and the graph kfunc argument is
rejected.

Also exercise a graph kptr loaded while a spin lock provides implicit RCU
protection. The pointer must be invalidated when the lock is released, which
guards the required ordering between non-owning-reference invalidation and
RCU demotion.

Update the existing fault-protected load test state description. The
post-unlock pointer no longer carries NON_OWN_REF, but remains readable
because the load is rewritten to use BPF_PROBE_MEM.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260904084325.52250-7-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 122 insertions, 0 deletions

diff --git a/security/apparmor/Kconfig b/security/apparmor/Kconfig
new file mode 100644
index 000000000..1e3bd4464
--- /dev/null
+++ b/security/apparmor/Kconfig
@@ -0,0 +1,122 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config SECURITY_APPARMOR
+	bool "AppArmor support"
+	depends on SECURITY && NET
+	select AUDIT
+	select SECURITY_PATH
+	select SECURITYFS
+	select SECURITY_NETWORK
+	default n
+	help
+	  This enables the AppArmor security module.
+	  Required userspace tools (if they are not included in your
+	  distribution) and further information may be found at
+	  http://apparmor.wiki.kernel.org
+
+	  If you are unsure how to answer this question, answer N.
+
+config SECURITY_APPARMOR_DEBUG
+	bool "Build AppArmor with debug code"
+	depends on SECURITY_APPARMOR
+	default n
+	help
+	  Build apparmor with debugging logic in apparmor. Not all
+	  debugging logic will necessarily be enabled. A submenu will
+	  provide fine grained control of the debug options that are
+	  available.
+
+config SECURITY_APPARMOR_DEBUG_ASSERTS
+	bool "Build AppArmor with debugging asserts"
+	depends on SECURITY_APPARMOR_DEBUG
+	default y
+	help
+	  Enable code assertions made with AA_BUG. These are primarily
+	  function entry preconditions but also exist at other key
+	  points. If the assert is triggered it will trigger a WARN
+	  message.
+
+config SECURITY_APPARMOR_DEBUG_MESSAGES
+	bool "Debug messages enabled by default"
+	depends on SECURITY_APPARMOR_DEBUG
+	default n
+	help
+	  Set the default value of the apparmor.debug kernel parameter.
+	  When enabled, various debug messages will be logged to
+	  the kernel message buffer.
+
+config SECURITY_APPARMOR_INTROSPECT_POLICY
+	bool "Allow loaded policy to be introspected"
+	depends on SECURITY_APPARMOR
+	default y
+	help
+	  This option selects whether introspection of loaded policy
+	  is available to userspace via the apparmor filesystem. This
+	  adds to kernel memory usage. It is required for introspection
+	  of loaded policy, and check point and restore support. It
+	  can be disabled for embedded systems where reducing memory and
+	  cpu is paramount.
+
+config SECURITY_APPARMOR_HASH
+	bool "Enable introspection of sha256 hashes for loaded profiles"
+	depends on SECURITY_APPARMOR_INTROSPECT_POLICY
+	select CRYPTO_LIB_SHA256
+	default y
+	help
+	  This option selects whether introspection of loaded policy
+	  hashes is available to userspace via the apparmor
+	  filesystem. This option provides a light weight means of
+	  checking loaded policy.  This option adds to policy load
+	  time and can be disabled for small embedded systems.
+
+config SECURITY_APPARMOR_HASH_DEFAULT
+       bool "Enable policy hash introspection by default"
+       depends on SECURITY_APPARMOR_HASH
+       default y
+       help
+	 This option selects whether sha256 hashing of loaded policy
+	 is enabled by default. The generation of sha256 hashes for
+	 loaded policy provide system administrators a quick way to
+	 verify that policy in the kernel matches what is expected,
+	 however it can slow down policy load on some devices. In
+	 these cases policy hashing can be disabled by default and
+	 enabled only if needed.
+
+config SECURITY_APPARMOR_EXPORT_BINARY
+	bool "Allow exporting the raw binary policy"
+	depends on SECURITY_APPARMOR_INTROSPECT_POLICY
+	select ZSTD_COMPRESS
+	select ZSTD_DECOMPRESS
+	default y
+	help
+	  This option allows reading back binary policy as it was loaded.
+	  It increases the amount of kernel memory needed by policy and
+	  also increases policy load time. This option is required for
+	  checkpoint and restore support, and debugging of loaded policy.
+
+config SECURITY_APPARMOR_PARANOID_LOAD
+	bool "Perform full verification of loaded policy"
+	depends on SECURITY_APPARMOR
+	default y
+	help
+	  This options allows controlling whether apparmor does a full
+	  verification of loaded policy. This should not be disabled
+	  except for embedded systems where the image is read only,
+	  includes policy, and has some form of integrity check.
+	  Disabling the check will speed up policy loads.
+
+config SECURITY_APPARMOR_KUNIT_TEST
+	tristate "Build KUnit tests for policy_unpack.c" if !KUNIT_ALL_TESTS
+	depends on KUNIT && SECURITY_APPARMOR
+	default KUNIT_ALL_TESTS
+	help
+	  This builds the AppArmor KUnit tests.
+
+	  KUnit tests run during boot and output the results to the debug log
+	  in TAP format (https://testanything.org/). Only useful for kernel devs
+	  running KUnit test harness and are not for inclusion into a
+	  production build.
+
+	  For more information on KUnit and unit tests in general please refer
+	  to the KUnit documentation in Documentation/dev-tools/kunit/.
+
+	  If unsure, say N.