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, 63 insertions, 0 deletions

diff --git a/arch/arm/crypto/Kconfig b/arch/arm/crypto/Kconfig
new file mode 100644
index 000000000..f884b8b2f
--- /dev/null
+++ b/arch/arm/crypto/Kconfig
@@ -0,0 +1,63 @@
+# SPDX-License-Identifier: GPL-2.0
+
+menu "Accelerated Cryptographic Algorithms for CPU (arm)"
+
+config CRYPTO_GHASH_ARM_CE
+	tristate "AEAD cipher: AES in GCM mode (ARMv8 Crypto Extensions)"
+	depends on KERNEL_MODE_NEON
+	select CRYPTO_AEAD
+	select CRYPTO_LIB_AES
+	select CRYPTO_LIB_GF128MUL
+	help
+	  AEAD cipher: AES-GCM
+
+	  Architecture: arm using
+	  - ARMv8 Crypto Extensions
+
+config CRYPTO_AES_ARM_BS
+	tristate "Ciphers: AES, modes: ECB/CBC/CTR/XTS (bit-sliced NEON)"
+	depends on KERNEL_MODE_NEON
+	select CRYPTO_SKCIPHER
+	select CRYPTO_LIB_AES
+	help
+	  Length-preserving ciphers: AES cipher algorithms (FIPS-197)
+	  with block cipher modes:
+	   - ECB (Electronic Codebook) mode (NIST SP800-38A)
+	   - CBC (Cipher Block Chaining) mode (NIST SP800-38A)
+	   - CTR (Counter) mode (NIST SP800-38A)
+	   - XTS (XOR Encrypt XOR with ciphertext stealing) mode (NIST SP800-38E
+	     and IEEE 1619)
+
+	  Bit sliced AES gives around 45% speedup on Cortex-A15 for CTR mode
+	  and for XTS mode encryption, CBC and XTS mode decryption speedup is
+	  around 25%. (CBC encryption speed is not affected by this driver.)
+
+	  The bit sliced AES code does not use lookup tables, so it is believed
+	  to be invulnerable to cache timing attacks. However, since the bit
+	  sliced AES code cannot process single blocks efficiently, in certain
+	  cases table-based code with some countermeasures against cache timing
+	  attacks will still be used as a fallback method; specifically CBC
+	  encryption (not CBC decryption), the encryption of XTS tweaks, XTS
+	  ciphertext stealing when the message isn't a multiple of 16 bytes, and
+	  CTR when invoked in a context in which NEON instructions are unusable.
+
+config CRYPTO_AES_ARM_CE
+	tristate "Ciphers: AES, modes: ECB/CBC/CTS/CTR/XTS (ARMv8 Crypto Extensions)"
+	depends on KERNEL_MODE_NEON
+	select CRYPTO_SKCIPHER
+	select CRYPTO_LIB_AES
+	help
+	  Length-preserving ciphers: AES cipher algorithms (FIPS-197)
+	   with block cipher modes:
+	   - ECB (Electronic Codebook) mode (NIST SP800-38A)
+	   - CBC (Cipher Block Chaining) mode (NIST SP800-38A)
+	   - CTR (Counter) mode (NIST SP800-38A)
+	   - CTS (Cipher Text Stealing) mode (NIST SP800-38A)
+	   - XTS (XOR Encrypt XOR with ciphertext stealing) mode (NIST SP800-38E
+	     and IEEE 1619)
+
+	  Architecture: arm using:
+	  - ARMv8 Crypto Extensions
+
+endmenu
+