From 6668ed271eaefaa63e686bdfbedaeb7b8e492722 Mon Sep 17 00:00:00 2001 From: Kumar Kartikeya Dwivedi Date: Fri, 4 Sep 2026 10:43:19 +0200 Subject: selftests/bpf: Reject graph kptr use after RCU unlock 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 Link: https://lore.kernel.org/r/20260904084325.52250-7-memxor@gmail.com Signed-off-by: Alexei Starovoitov --- include/crypto/mldsa.h | 62 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 62 insertions(+) create mode 100644 include/crypto/mldsa.h (limited to 'include/crypto/mldsa.h') diff --git a/include/crypto/mldsa.h b/include/crypto/mldsa.h new file mode 100644 index 000000000..3ef267678 --- /dev/null +++ b/include/crypto/mldsa.h @@ -0,0 +1,62 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Support for verifying ML-DSA signatures + * + * Copyright 2025 Google LLC + */ +#ifndef _CRYPTO_MLDSA_H +#define _CRYPTO_MLDSA_H + +#include + +/* Identifier for an ML-DSA parameter set */ +enum mldsa_alg { + MLDSA44, /* ML-DSA-44 */ + MLDSA65, /* ML-DSA-65 */ + MLDSA87, /* ML-DSA-87 */ +}; + +/* Lengths of ML-DSA public keys and signatures in bytes */ +#define MLDSA44_PUBLIC_KEY_SIZE 1312 +#define MLDSA65_PUBLIC_KEY_SIZE 1952 +#define MLDSA87_PUBLIC_KEY_SIZE 2592 +#define MLDSA44_SIGNATURE_SIZE 2420 +#define MLDSA65_SIGNATURE_SIZE 3309 +#define MLDSA87_SIGNATURE_SIZE 4627 + +/** + * mldsa_verify() - Verify an ML-DSA signature + * @alg: The ML-DSA parameter set to use + * @sig: The signature + * @sig_len: Length of the signature in bytes. Should match the + * MLDSA*_SIGNATURE_SIZE constant associated with @alg, + * otherwise -EBADMSG will be returned. + * @msg: The message + * @msg_len: Length of the message in bytes + * @pk: The public key + * @pk_len: Length of the public key in bytes. Should match the + * MLDSA*_PUBLIC_KEY_SIZE constant associated with @alg, + * otherwise -EBADMSG will be returned. + * + * This verifies a signature using pure ML-DSA with the specified parameter set. + * The context string is assumed to be empty. This corresponds to FIPS 204 + * Algorithm 3 "ML-DSA.Verify" with the ctx parameter set to the empty string + * and the lengths of the signature and key given explicitly by the caller. + * + * Context: Might sleep + * + * Return: + * * 0 if the signature is valid + * * -EBADMSG if the signature and/or public key is malformed + * * -EKEYREJECTED if the signature is invalid but otherwise well-formed + * * -ENOMEM if out of memory so the validity of the signature is unknown + */ +int mldsa_verify(enum mldsa_alg alg, const u8 *sig, size_t sig_len, + const u8 *msg, size_t msg_len, const u8 *pk, size_t pk_len); + +#if IS_ENABLED(CONFIG_CRYPTO_LIB_MLDSA_KUNIT_TEST) +/* Internal function, exposed only for unit testing */ +s32 mldsa_use_hint(u8 h, s32 r, s32 gamma2); +#endif + +#endif /* _CRYPTO_MLDSA_H */ -- cgit v1.3.1