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/sm3.c | 89 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 89 insertions(+) create mode 100644 crypto/sm3.c (limited to 'crypto/sm3.c') diff --git a/crypto/sm3.c b/crypto/sm3.c new file mode 100644 index 000000000..05111a99b --- /dev/null +++ b/crypto/sm3.c @@ -0,0 +1,89 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * SM3 secure hash, as specified by OSCCA GM/T 0004-2012 SM3 and + * described at https://tools.ietf.org/html/draft-shen-sm3-hash-01 + * + * Copyright (C) 2017 ARM Limited or its affiliates. + * Written by Gilad Ben-Yossef + * Copyright (C) 2021 Tianjia Zhang + * Copyright 2026 Google LLC + */ + +#include +#include +#include +#include + +#define SM3_CTX(desc) ((struct sm3_ctx *)shash_desc_ctx(desc)) + +static int crypto_sm3_init(struct shash_desc *desc) +{ + sm3_init(SM3_CTX(desc)); + return 0; +} + +static int crypto_sm3_update(struct shash_desc *desc, + const u8 *data, unsigned int len) +{ + sm3_update(SM3_CTX(desc), data, len); + return 0; +} + +static int crypto_sm3_final(struct shash_desc *desc, u8 *out) +{ + sm3_final(SM3_CTX(desc), out); + return 0; +} + +static int crypto_sm3_digest(struct shash_desc *desc, + const u8 *data, unsigned int len, u8 *out) +{ + sm3(data, len, out); + return 0; +} + +static int crypto_sm3_export_core(struct shash_desc *desc, void *out) +{ + memcpy(out, SM3_CTX(desc), sizeof(struct sm3_ctx)); + return 0; +} + +static int crypto_sm3_import_core(struct shash_desc *desc, const void *in) +{ + memcpy(SM3_CTX(desc), in, sizeof(struct sm3_ctx)); + return 0; +} + +static struct shash_alg sm3_alg = { + .base.cra_name = "sm3", + .base.cra_driver_name = "sm3-lib", + .base.cra_priority = 300, + .base.cra_blocksize = SM3_BLOCK_SIZE, + .base.cra_module = THIS_MODULE, + .digestsize = SM3_DIGEST_SIZE, + .init = crypto_sm3_init, + .update = crypto_sm3_update, + .final = crypto_sm3_final, + .digest = crypto_sm3_digest, + .export_core = crypto_sm3_export_core, + .import_core = crypto_sm3_import_core, + .descsize = sizeof(struct sm3_ctx), +}; + +static int __init crypto_sm3_mod_init(void) +{ + return crypto_register_shash(&sm3_alg); +} +module_init(crypto_sm3_mod_init); + +static void __exit crypto_sm3_mod_exit(void) +{ + crypto_unregister_shash(&sm3_alg); +} +module_exit(crypto_sm3_mod_exit); + +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("Crypto API support for SM3"); + +MODULE_ALIAS_CRYPTO("sm3"); +MODULE_ALIAS_CRYPTO("sm3-lib"); -- cgit v1.3.1