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 --- security/integrity/evm/evm.h | 89 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 89 insertions(+) create mode 100644 security/integrity/evm/evm.h (limited to 'security/integrity/evm/evm.h') diff --git a/security/integrity/evm/evm.h b/security/integrity/evm/evm.h new file mode 100644 index 000000000..694552ace --- /dev/null +++ b/security/integrity/evm/evm.h @@ -0,0 +1,89 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2005-2010 IBM Corporation + * + * Authors: + * Mimi Zohar + * Kylene Hall + * + * File: evm.h + */ + +#ifndef __INTEGRITY_EVM_H +#define __INTEGRITY_EVM_H + +#include +#include + +#include "../integrity.h" + +#define EVM_INIT_HMAC 0x0001 +#define EVM_INIT_X509 0x0002 +#define EVM_ALLOW_METADATA_WRITES 0x0004 +#define EVM_SIGV3_REQUIRED 0x0008 +#define EVM_SETUP_COMPLETE 0x80000000 /* userland has signaled key load */ + +#define EVM_KEY_MASK (EVM_INIT_HMAC | EVM_INIT_X509) +#define EVM_INIT_MASK (EVM_INIT_HMAC | EVM_INIT_X509 | EVM_SETUP_COMPLETE | \ + EVM_ALLOW_METADATA_WRITES | EVM_SIGV3_REQUIRED) + +struct xattr_list { + struct list_head list; + char *name; + bool enabled; +}; + +#define EVM_NEW_FILE 0x00000001 +#define EVM_IMMUTABLE_DIGSIG 0x00000002 + +/* EVM integrity metadata associated with an inode */ +struct evm_iint_cache { + unsigned long flags; + enum integrity_status evm_status:4; + struct integrity_inode_attributes metadata_inode; +}; + +extern struct lsm_blob_sizes evm_blob_sizes; + +static inline struct evm_iint_cache *evm_iint_inode(const struct inode *inode) +{ + if (unlikely(!inode->i_security)) + return NULL; + + return inode->i_security + evm_blob_sizes.lbs_inode; +} + +extern int evm_initialized; + +#define EVM_ATTR_FSUUID 0x0001 + +extern int evm_hmac_attrs; + +/* List of EVM protected security xattrs */ +extern struct list_head evm_config_xattrnames; + +struct evm_digest { + struct ima_digest_data_hdr hdr; + char digest[IMA_MAX_DIGEST_SIZE]; +} __packed; + +int evm_protected_xattr(const char *req_xattr_name); + +int evm_init_key(void); +int evm_update_evmxattr(struct dentry *dentry, + const char *req_xattr_name, + const char *req_xattr_value, + size_t req_xattr_value_len); +int evm_calc_hmac(struct dentry *dentry, const char *req_xattr_name, + const char *req_xattr_value, + size_t req_xattr_value_len, struct evm_digest *data, + struct evm_iint_cache *iint); +int evm_calc_hash(struct dentry *dentry, const char *req_xattr_name, + const char *req_xattr_value, + size_t req_xattr_value_len, char type, + struct evm_digest *data, struct evm_iint_cache *iint); +int evm_init_hmac(struct inode *inode, const struct xattr *xattrs, + char *hmac_val); +int evm_init_secfs(void); + +#endif -- cgit v1.3.1