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/pkcs7.h | 47 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 47 insertions(+) create mode 100644 include/crypto/pkcs7.h (limited to 'include/crypto/pkcs7.h') diff --git a/include/crypto/pkcs7.h b/include/crypto/pkcs7.h new file mode 100644 index 000000000..38ec7f5f9 --- /dev/null +++ b/include/crypto/pkcs7.h @@ -0,0 +1,47 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* PKCS#7 crypto data parser + * + * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#ifndef _CRYPTO_PKCS7_H +#define _CRYPTO_PKCS7_H + +#include +#include +#include + +struct key; +struct pkcs7_message; + +/* + * pkcs7_parser.c + */ +extern struct pkcs7_message *pkcs7_parse_message(const void *data, + size_t datalen); +extern void pkcs7_free_message(struct pkcs7_message *pkcs7); + +extern int pkcs7_get_content_data(const struct pkcs7_message *pkcs7, + const void **_data, size_t *_datalen, + size_t *_headerlen); + +/* + * pkcs7_trust.c + */ +extern int pkcs7_validate_trust(struct pkcs7_message *pkcs7, + struct key *trust_keyring); + +/* + * pkcs7_verify.c + */ +extern int pkcs7_verify(struct pkcs7_message *pkcs7, + enum key_being_used_for usage); + +extern int pkcs7_supply_detached_data(struct pkcs7_message *pkcs7, + const void *data, size_t datalen); + +extern int pkcs7_get_digest(struct pkcs7_message *pkcs7, const u8 **buf, + u32 *len, enum hash_algo *hash_algo); + +#endif /* _CRYPTO_PKCS7_H */ -- cgit v1.3.1