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/internal/poly1305.h | 56 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 56 insertions(+) create mode 100644 include/crypto/internal/poly1305.h (limited to 'include/crypto/internal/poly1305.h') diff --git a/include/crypto/internal/poly1305.h b/include/crypto/internal/poly1305.h new file mode 100644 index 000000000..a72fff409 --- /dev/null +++ b/include/crypto/internal/poly1305.h @@ -0,0 +1,56 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Common values for the Poly1305 algorithm + */ + +#ifndef _CRYPTO_INTERNAL_POLY1305_H +#define _CRYPTO_INTERNAL_POLY1305_H + +#include +#include + +/* + * Poly1305 core functions. These only accept whole blocks; the caller must + * handle any needed block buffering and padding. 'hibit' must be 1 for any + * full blocks, or 0 for the final block if it had to be padded. If 'nonce' is + * non-NULL, then it's added at the end to compute the Poly1305 MAC. Otherwise, + * only the ε-almost-∆-universal hash function (not the full MAC) is computed. + */ + +void poly1305_core_setkey(struct poly1305_core_key *key, + const u8 raw_key[POLY1305_BLOCK_SIZE]); +static inline void poly1305_core_init(struct poly1305_state *state) +{ + *state = (struct poly1305_state){}; +} + +void poly1305_core_blocks(struct poly1305_state *state, + const struct poly1305_core_key *key, const void *src, + unsigned int nblocks, u32 hibit); +void poly1305_core_emit(const struct poly1305_state *state, const u32 nonce[4], + void *dst); + +static inline void +poly1305_block_init_generic(struct poly1305_block_state *desc, + const u8 raw_key[POLY1305_BLOCK_SIZE]) +{ + poly1305_core_init(&desc->h); + poly1305_core_setkey(&desc->core_r, raw_key); +} + +static inline void poly1305_blocks_generic(struct poly1305_block_state *state, + const u8 *src, unsigned int len, + u32 padbit) +{ + poly1305_core_blocks(&state->h, &state->core_r, src, + len / POLY1305_BLOCK_SIZE, padbit); +} + +static inline void poly1305_emit_generic(const struct poly1305_state *state, + u8 digest[POLY1305_DIGEST_SIZE], + const u32 nonce[4]) +{ + poly1305_core_emit(state, nonce, digest); +} + +#endif -- cgit v1.3.1