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 --- lib/crypto/poly1305.c | 100 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 100 insertions(+) create mode 100644 lib/crypto/poly1305.c (limited to 'lib/crypto/poly1305.c') diff --git a/lib/crypto/poly1305.c b/lib/crypto/poly1305.c new file mode 100644 index 000000000..f313ccc4b --- /dev/null +++ b/lib/crypto/poly1305.c @@ -0,0 +1,100 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Poly1305 authenticator algorithm, RFC7539 + * + * Copyright (C) 2015 Martin Willi + * + * Based on public domain code by Andrew Moon and Daniel J. Bernstein. + */ + +#include +#include +#include +#include +#include +#include + +#ifdef CONFIG_CRYPTO_LIB_POLY1305_ARCH +#include "poly1305.h" /* $(SRCARCH)/poly1305.h */ +#else +#define poly1305_block_init poly1305_block_init_generic +#define poly1305_blocks poly1305_blocks_generic +#define poly1305_emit poly1305_emit_generic +#endif + +void poly1305_init(struct poly1305_desc_ctx *desc, + const u8 key[POLY1305_KEY_SIZE]) +{ + desc->s[0] = get_unaligned_le32(key + 16); + desc->s[1] = get_unaligned_le32(key + 20); + desc->s[2] = get_unaligned_le32(key + 24); + desc->s[3] = get_unaligned_le32(key + 28); + desc->buflen = 0; + poly1305_block_init(&desc->state, key); +} +EXPORT_SYMBOL(poly1305_init); + +void poly1305_update(struct poly1305_desc_ctx *desc, + const u8 *src, unsigned int nbytes) +{ + if (desc->buflen + nbytes >= POLY1305_BLOCK_SIZE) { + unsigned int bulk_len; + + if (desc->buflen) { + unsigned int l = POLY1305_BLOCK_SIZE - desc->buflen; + + memcpy(&desc->buf[desc->buflen], src, l); + src += l; + nbytes -= l; + + poly1305_blocks(&desc->state, desc->buf, + POLY1305_BLOCK_SIZE, 1); + desc->buflen = 0; + } + + bulk_len = round_down(nbytes, POLY1305_BLOCK_SIZE); + nbytes %= POLY1305_BLOCK_SIZE; + + if (bulk_len) { + poly1305_blocks(&desc->state, src, bulk_len, 1); + src += bulk_len; + } + } + if (nbytes) { + memcpy(&desc->buf[desc->buflen], src, nbytes); + desc->buflen += nbytes; + } +} +EXPORT_SYMBOL(poly1305_update); + +void poly1305_final(struct poly1305_desc_ctx *desc, u8 *dst) +{ + if (unlikely(desc->buflen)) { + desc->buf[desc->buflen++] = 1; + memset(desc->buf + desc->buflen, 0, + POLY1305_BLOCK_SIZE - desc->buflen); + poly1305_blocks(&desc->state, desc->buf, POLY1305_BLOCK_SIZE, + 0); + } + + poly1305_emit(&desc->state.h, dst, desc->s); + *desc = (struct poly1305_desc_ctx){}; +} +EXPORT_SYMBOL(poly1305_final); + +#ifdef poly1305_mod_init_arch +static int __init poly1305_mod_init(void) +{ + poly1305_mod_init_arch(); + return 0; +} +subsys_initcall(poly1305_mod_init); + +static void __exit poly1305_mod_exit(void) +{ +} +module_exit(poly1305_mod_exit); +#endif + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Poly1305 authenticator algorithm, RFC7539"); -- cgit v1.3.1