From 78004e9a87f240df03e2f73120d291763c32e0a7 Mon Sep 17 00:00:00 2001 From: Ali Ahmet Memis Date: Fri, 21 Aug 2026 01:45:27 +0000 Subject: openrisc: fix arbitrary kernel memory access via or1k_atomic syscall sys_or1k_atomic() (syscall 244 in the "or1k" ABI) takes two user pointers, v1 and v2, and swaps the words they point to in hand-written assembly. l.lwz r29,0(r4) l.lwz r27,0(r5) l.sw 0(r4),r27 l.sw 0(r5),r29 The pointers are not checked with access_ok(). The four memory accesses also have no exception table entries. A caller passes a kernel address as either pointer, and the syscall reads from and writes to it directly. This gives an unprivileged process a kernel read/write primitive. It overwrites kernel data such as the sys_call_table, gaining code execution in kernel context. Check both pointers before entering the critical section. Add fixups for the four memory accesses so faults on valid but unmapped user addresses return -EFAULT. [shorne@gmail.com: fix comment style] Fixes: 9d02a4283e9c ("OpenRISC: Boot code") Cc: stable@vger.kernel.org Signed-off-by: Ali Ahmet Memis Signed-off-by: Stafford Horne --- 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