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/internal/rsa.h | 86 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 86 insertions(+) create mode 100644 include/crypto/internal/rsa.h (limited to 'include/crypto/internal/rsa.h') diff --git a/include/crypto/internal/rsa.h b/include/crypto/internal/rsa.h new file mode 100644 index 000000000..071a1951b --- /dev/null +++ b/include/crypto/internal/rsa.h @@ -0,0 +1,86 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * RSA internal helpers + * + * Copyright (c) 2015, Intel Corporation + * Authors: Tadeusz Struk + */ +#ifndef _RSA_HELPER_ +#define _RSA_HELPER_ +#include +#include + +/** + * rsa_key - RSA key structure + * @n : RSA modulus raw byte stream + * @e : RSA public exponent raw byte stream + * @d : RSA private exponent raw byte stream + * @p : RSA prime factor p of n raw byte stream + * @q : RSA prime factor q of n raw byte stream + * @dp : RSA exponent d mod (p - 1) raw byte stream + * @dq : RSA exponent d mod (q - 1) raw byte stream + * @qinv : RSA CRT coefficient q^(-1) mod p raw byte stream + * @n_sz : length in bytes of RSA modulus n + * @e_sz : length in bytes of RSA public exponent + * @d_sz : length in bytes of RSA private exponent + * @p_sz : length in bytes of p field + * @q_sz : length in bytes of q field + * @dp_sz : length in bytes of dp field + * @dq_sz : length in bytes of dq field + * @qinv_sz : length in bytes of qinv field + */ +struct rsa_key { + const u8 *n; + const u8 *e; + const u8 *d; + const u8 *p; + const u8 *q; + const u8 *dp; + const u8 *dq; + const u8 *qinv; + size_t n_sz; + size_t e_sz; + size_t d_sz; + size_t p_sz; + size_t q_sz; + size_t dp_sz; + size_t dq_sz; + size_t qinv_sz; +}; + +int rsa_parse_pub_key(struct rsa_key *rsa_key, const void *key, + unsigned int key_len); + +int rsa_parse_priv_key(struct rsa_key *rsa_key, const void *key, + unsigned int key_len); + +#define RSA_PUB (true) +#define RSA_PRIV (false) + +static inline int rsa_set_key(struct crypto_akcipher *child, + unsigned int *key_size, bool is_pubkey, + const void *key, unsigned int keylen) +{ + int err; + + *key_size = 0; + + if (is_pubkey) + err = crypto_akcipher_set_pub_key(child, key, keylen); + else + err = crypto_akcipher_set_priv_key(child, key, keylen); + if (err) + return err; + + /* Find out new modulus size from rsa implementation */ + err = crypto_akcipher_maxsize(child); + if (err > PAGE_SIZE) + return -ENOTSUPP; + + *key_size = err; + return 0; +} + +extern struct crypto_template rsa_pkcs1pad_tmpl; +extern struct crypto_template rsassa_pkcs1_tmpl; +#endif -- cgit v1.3.1