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 --- crypto/rsa_helper.c | 186 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 186 insertions(+) create mode 100644 crypto/rsa_helper.c (limited to 'crypto/rsa_helper.c') diff --git a/crypto/rsa_helper.c b/crypto/rsa_helper.c new file mode 100644 index 000000000..94266f290 --- /dev/null +++ b/crypto/rsa_helper.c @@ -0,0 +1,186 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * RSA key extract helper + * + * Copyright (c) 2015, Intel Corporation + * Authors: Tadeusz Struk + */ +#include +#include +#include +#include +#include +#include "rsapubkey.asn1.h" +#include "rsaprivkey.asn1.h" + +int rsa_get_n(void *context, size_t hdrlen, unsigned char tag, + const void *value, size_t vlen) +{ + struct rsa_key *key = context; + const u8 *ptr = value; + size_t n_sz = vlen; + + /* invalid key provided */ + if (!value || !vlen) + return -EINVAL; + + if (fips_enabled) { + while (n_sz && !*ptr) { + ptr++; + n_sz--; + } + + /* In FIPS mode only allow key size 2K and higher */ + if (n_sz < 256) { + pr_err("RSA: key size not allowed in FIPS mode\n"); + return -EINVAL; + } + } + + key->n = value; + key->n_sz = vlen; + + return 0; +} + +int rsa_get_e(void *context, size_t hdrlen, unsigned char tag, + const void *value, size_t vlen) +{ + struct rsa_key *key = context; + + /* invalid key provided */ + if (!value || !key->n_sz || !vlen || vlen > key->n_sz) + return -EINVAL; + + key->e = value; + key->e_sz = vlen; + + return 0; +} + +int rsa_get_d(void *context, size_t hdrlen, unsigned char tag, + const void *value, size_t vlen) +{ + struct rsa_key *key = context; + + /* invalid key provided */ + if (!value || !key->n_sz || !vlen || vlen > key->n_sz) + return -EINVAL; + + key->d = value; + key->d_sz = vlen; + + return 0; +} + +int rsa_get_p(void *context, size_t hdrlen, unsigned char tag, + const void *value, size_t vlen) +{ + struct rsa_key *key = context; + + /* invalid key provided */ + if (!value || !vlen || vlen > key->n_sz) + return -EINVAL; + + key->p = value; + key->p_sz = vlen; + + return 0; +} + +int rsa_get_q(void *context, size_t hdrlen, unsigned char tag, + const void *value, size_t vlen) +{ + struct rsa_key *key = context; + + /* invalid key provided */ + if (!value || !vlen || vlen > key->n_sz) + return -EINVAL; + + key->q = value; + key->q_sz = vlen; + + return 0; +} + +int rsa_get_dp(void *context, size_t hdrlen, unsigned char tag, + const void *value, size_t vlen) +{ + struct rsa_key *key = context; + + /* invalid key provided */ + if (!value || !vlen || vlen > key->n_sz) + return -EINVAL; + + key->dp = value; + key->dp_sz = vlen; + + return 0; +} + +int rsa_get_dq(void *context, size_t hdrlen, unsigned char tag, + const void *value, size_t vlen) +{ + struct rsa_key *key = context; + + /* invalid key provided */ + if (!value || !vlen || vlen > key->n_sz) + return -EINVAL; + + key->dq = value; + key->dq_sz = vlen; + + return 0; +} + +int rsa_get_qinv(void *context, size_t hdrlen, unsigned char tag, + const void *value, size_t vlen) +{ + struct rsa_key *key = context; + + /* invalid key provided */ + if (!value || !vlen || vlen > key->n_sz) + return -EINVAL; + + key->qinv = value; + key->qinv_sz = vlen; + + return 0; +} + +/** + * rsa_parse_pub_key() - decodes the BER encoded buffer and stores in the + * provided struct rsa_key, pointers to the raw key as is, + * so that the caller can copy it or MPI parse it, etc. + * + * @rsa_key: struct rsa_key key representation + * @key: key in BER format + * @key_len: length of key + * + * Return: 0 on success or error code in case of error + */ +int rsa_parse_pub_key(struct rsa_key *rsa_key, const void *key, + unsigned int key_len) +{ + return asn1_ber_decoder(&rsapubkey_decoder, rsa_key, key, key_len); +} +EXPORT_SYMBOL_GPL(rsa_parse_pub_key); + +/** + * rsa_parse_priv_key() - decodes the BER encoded buffer and stores in the + * provided struct rsa_key, pointers to the raw key + * as is, so that the caller can copy it or MPI parse it, + * etc. + * + * @rsa_key: struct rsa_key key representation + * @key: key in BER format + * @key_len: length of key + * + * Return: 0 on success or error code in case of error + */ +int rsa_parse_priv_key(struct rsa_key *rsa_key, const void *key, + unsigned int key_len) +{ + return asn1_ber_decoder(&rsaprivkey_decoder, rsa_key, key, key_len); +} +EXPORT_SYMBOL_GPL(rsa_parse_priv_key); -- cgit v1.3.1