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/serpent.h | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) create mode 100644 include/crypto/serpent.h (limited to 'include/crypto/serpent.h') diff --git a/include/crypto/serpent.h b/include/crypto/serpent.h new file mode 100644 index 000000000..75c7eaa20 --- /dev/null +++ b/include/crypto/serpent.h @@ -0,0 +1,28 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Common values for serpent algorithms + */ + +#ifndef _CRYPTO_SERPENT_H +#define _CRYPTO_SERPENT_H + +#include +#include + +#define SERPENT_MIN_KEY_SIZE 0 +#define SERPENT_MAX_KEY_SIZE 32 +#define SERPENT_EXPKEY_WORDS 132 +#define SERPENT_BLOCK_SIZE 16 + +struct serpent_ctx { + u32 expkey[SERPENT_EXPKEY_WORDS]; +}; + +int __serpent_setkey(struct serpent_ctx *ctx, const u8 *key, + unsigned int keylen); +int serpent_setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen); + +void __serpent_encrypt(const void *ctx, u8 *dst, const u8 *src); +void __serpent_decrypt(const void *ctx, u8 *dst, const u8 *src); + +#endif -- cgit v1.3.1