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/poly1305.h | 67 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 67 insertions(+) create mode 100644 include/crypto/poly1305.h (limited to 'include/crypto/poly1305.h') diff --git a/include/crypto/poly1305.h b/include/crypto/poly1305.h new file mode 100644 index 000000000..190beb427 --- /dev/null +++ b/include/crypto/poly1305.h @@ -0,0 +1,67 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Common values for the Poly1305 algorithm + */ + +#ifndef _CRYPTO_POLY1305_H +#define _CRYPTO_POLY1305_H + +#include + +#define POLY1305_BLOCK_SIZE 16 +#define POLY1305_KEY_SIZE 32 +#define POLY1305_DIGEST_SIZE 16 + +/* The poly1305_key and poly1305_state types are mostly opaque and + * implementation-defined. Limbs might be in base 2^64 or base 2^26, or + * different yet. The union type provided keeps these 64-bit aligned for the + * case in which this is implemented using 64x64 multiplies. + */ + +struct poly1305_key { + union { + u32 r[5]; + u64 r64[3]; + }; +}; + +struct poly1305_core_key { + struct poly1305_key key; + struct poly1305_key precomputed_s; +}; + +struct poly1305_state { + union { + u32 h[5]; + u64 h64[3]; + }; +}; + +/* Combined state for block function. */ +struct poly1305_block_state { + /* accumulator */ + struct poly1305_state h; + /* key */ + union { + struct poly1305_key opaque_r[CONFIG_CRYPTO_LIB_POLY1305_RSIZE]; + struct poly1305_core_key core_r; + }; +}; + +struct poly1305_desc_ctx { + /* partial buffer */ + u8 buf[POLY1305_BLOCK_SIZE]; + /* bytes used in partial buffer */ + unsigned int buflen; + /* finalize key */ + u32 s[4]; + struct poly1305_block_state state; +}; + +void poly1305_init(struct poly1305_desc_ctx *desc, + const u8 key[at_least POLY1305_KEY_SIZE]); +void poly1305_update(struct poly1305_desc_ctx *desc, + const u8 *src, unsigned int nbytes); +void poly1305_final(struct poly1305_desc_ctx *desc, u8 *digest); + +#endif -- cgit v1.3.1