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/b128ops.h | 72 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 72 insertions(+) create mode 100644 include/crypto/b128ops.h (limited to 'include/crypto/b128ops.h') diff --git a/include/crypto/b128ops.h b/include/crypto/b128ops.h new file mode 100644 index 000000000..f3b37cbb3 --- /dev/null +++ b/include/crypto/b128ops.h @@ -0,0 +1,72 @@ +/* b128ops.h - common 128-bit block operations + * + * Copyright (c) 2003, Dr Brian Gladman, Worcester, UK. + * Copyright (c) 2006, Rik Snel + * + * Based on Dr Brian Gladman's (GPL'd) work published at + * http://fp.gladman.plus.com/cryptography_technology/index.htm + * See the original copyright notice below. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the Free + * Software Foundation; either version 2 of the License, or (at your option) + * any later version. + */ +/* + --------------------------------------------------------------------------- + Copyright (c) 2003, Dr Brian Gladman, Worcester, UK. All rights reserved. + + LICENSE TERMS + + The free distribution and use of this software in both source and binary + form is allowed (with or without changes) provided that: + + 1. distributions of this source code include the above copyright + notice, this list of conditions and the following disclaimer; + + 2. distributions in binary form include the above copyright + notice, this list of conditions and the following disclaimer + in the documentation and/or other associated materials; + + 3. the copyright holder's name is not used to endorse products + built using this software without specific written permission. + + ALTERNATIVELY, provided that this notice is retained in full, this product + may be distributed under the terms of the GNU General Public License (GPL), + in which case the provisions of the GPL apply INSTEAD OF those given above. + + DISCLAIMER + + This software is provided 'as is' with no explicit or implied warranties + in respect of its properties, including, but not limited to, correctness + and/or fitness for purpose. + --------------------------------------------------------------------------- + Issue Date: 13/06/2006 +*/ + +#ifndef _CRYPTO_B128OPS_H +#define _CRYPTO_B128OPS_H + +#include + +typedef struct { + __be64 a, b; +} be128; + +typedef struct { + __le64 b, a; +} le128; + +static inline void be128_xor(be128 *r, const be128 *p, const be128 *q) +{ + r->a = p->a ^ q->a; + r->b = p->b ^ q->b; +} + +static inline void le128_xor(le128 *r, const le128 *p, const le128 *q) +{ + r->a = p->a ^ q->a; + r->b = p->b ^ q->b; +} + +#endif /* _CRYPTO_B128OPS_H */ -- cgit v1.3.1