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/ecdh.h | 83 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 83 insertions(+) create mode 100644 include/crypto/ecdh.h (limited to 'include/crypto/ecdh.h') diff --git a/include/crypto/ecdh.h b/include/crypto/ecdh.h new file mode 100644 index 000000000..9784ecdd2 --- /dev/null +++ b/include/crypto/ecdh.h @@ -0,0 +1,83 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * ECDH params to be used with kpp API + * + * Copyright (c) 2016, Intel Corporation + * Authors: Salvatore Benedetto + */ +#ifndef _CRYPTO_ECDH_ +#define _CRYPTO_ECDH_ + +/** + * DOC: ECDH Helper Functions + * + * To use ECDH with the KPP cipher API, the following data structure and + * functions should be used. + * + * The ECC curves known to the ECDH implementation are specified in this + * header file. + * + * To use ECDH with KPP, the following functions should be used to operate on + * an ECDH private key. The packet private key that can be set with + * the KPP API function call of crypto_kpp_set_secret. + */ + +/* Curves IDs */ +#define ECC_CURVE_NIST_P192 0x0001 +#define ECC_CURVE_NIST_P256 0x0002 +#define ECC_CURVE_NIST_P384 0x0003 +#define ECC_CURVE_NIST_P521 0x0004 + +/** + * struct ecdh - define an ECDH private key + * + * @key: Private ECDH key + * @key_size: Size of the private ECDH key + */ +struct ecdh { + char *key; + unsigned short key_size; +}; + +/** + * crypto_ecdh_key_len() - Obtain the size of the private ECDH key + * @params: private ECDH key + * + * This function returns the packet ECDH key size. A caller can use that + * with the provided ECDH private key reference to obtain the required + * memory size to hold a packet key. + * + * Return: size of the key in bytes + */ +unsigned int crypto_ecdh_key_len(const struct ecdh *params); + +/** + * crypto_ecdh_encode_key() - encode the private key + * @buf: Buffer allocated by the caller to hold the packet ECDH + * private key. The buffer should be at least crypto_ecdh_key_len + * bytes in size. + * @len: Length of the packet private key buffer + * @p: Buffer with the caller-specified private key + * + * The ECDH implementations operate on a packet representation of the private + * key. + * + * Return: -EINVAL if buffer has insufficient size, 0 on success + */ +int crypto_ecdh_encode_key(char *buf, unsigned int len, const struct ecdh *p); + +/** + * crypto_ecdh_decode_key() - decode a private key + * @buf: Buffer holding a packet key that should be decoded + * @len: Length of the packet private key buffer + * @p: Buffer allocated by the caller that is filled with the + * unpacked ECDH private key. + * + * The unpacking obtains the private key by pointing @p to the correct location + * in @buf. Thus, both pointers refer to the same memory. + * + * Return: -EINVAL if buffer has insufficient size, 0 on success + */ +int crypto_ecdh_decode_key(const char *buf, unsigned int len, struct ecdh *p); + +#endif -- cgit v1.3.1