[PATCH 24/28] ima: Move to LSM infrastructure
Roberto Sassu
roberto.sassu at huaweicloud.com
Fri Mar 3 18:25:58 UTC 2023
From: Roberto Sassu <roberto.sassu at huawei.com>
Remove hardcoded IMA function calls (not for appraisal) from the LSM
infrastructure, the VFS, NFS and the key subsystem.
Make those functions as static (except for ima_file_check() which is
exported, and ima_post_key_create_or_update(), which is not in ima_main.c),
and register them as implementation of the respective hooks in the new
function init_ima_lsm().
Call init_ima_lsm() from integrity_lsm_init() (renamed from
integrity_iintcache_init()), to make sure that the integrity subsystem is
ready at the time IMA hooks are registered. The same will be done for EVM,
by calling init_evm_lsm() just after init_ima_lsm().
Put 'integrity' at the end of the LSM list by setting the order to
LSM_ORDER_LAST. 'integrity' must be the last so that EVM can calculate the
HMAC on xattrs previously provided by the other selected LSMs.
Setting the order to LSM_ORDER_LAST also causes 'integrity' to be always
enabled regardless of the LSM choice. This avoids any risk that IMA and EVM
functions are not called when transitioning from an old kernel to one where
IMA and EVM are stacked.
Signed-off-by: Roberto Sassu <roberto.sassu at huawei.com>
---
fs/file_table.c | 2 -
fs/namei.c | 7 ---
fs/nfsd/vfs.c | 7 ---
fs/open.c | 1 -
include/linux/ima.h | 100 ------------------------------
security/integrity/iint.c | 8 ++-
security/integrity/ima/ima.h | 7 +++
security/integrity/ima/ima_main.c | 64 +++++++++++++------
security/integrity/integrity.h | 8 +++
security/keys/key.c | 9 +--
security/security.c | 53 +++-------------
11 files changed, 74 insertions(+), 192 deletions(-)
diff --git a/fs/file_table.c b/fs/file_table.c
index 3150e613aec..37f9bf5ed97 100644
--- a/fs/file_table.c
+++ b/fs/file_table.c
@@ -26,7 +26,6 @@
#include <linux/percpu_counter.h>
#include <linux/percpu.h>
#include <linux/task_work.h>
-#include <linux/ima.h>
#include <linux/swap.h>
#include <linux/kmemleak.h>
@@ -313,7 +312,6 @@ static void __fput(struct file *file)
locks_remove_file(file);
security_file_pre_free(file);
- ima_file_free(file);
if (unlikely(file->f_flags & FASYNC)) {
if (file->f_op->fasync)
file->f_op->fasync(-1, file, 0);
diff --git a/fs/namei.c b/fs/namei.c
index 8c4fdfd81d4..cd700d4e8cf 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -27,7 +27,6 @@
#include <linux/fsnotify.h>
#include <linux/personality.h>
#include <linux/security.h>
-#include <linux/ima.h>
#include <linux/syscalls.h>
#include <linux/mount.h>
#include <linux/audit.h>
@@ -3560,8 +3559,6 @@ static int do_open(struct nameidata *nd,
error = vfs_open(&nd->path, file);
if (!error)
error = security_file_post_open(file, op->acc_mode);
- if (!error)
- error = ima_file_check(file, op->acc_mode);
if (!error && do_truncate)
error = handle_truncate(idmap, file);
if (unlikely(error > 0)) {
@@ -3625,7 +3622,6 @@ static int vfs_tmpfile(struct mnt_idmap *idmap,
spin_unlock(&inode->i_lock);
}
security_inode_post_create_tmpfile(idmap, dir, file_dentry(file), mode);
- ima_post_create_tmpfile(idmap, dir, file_dentry(file), mode);
return 0;
}
@@ -3968,9 +3964,6 @@ static int do_mknodat(int dfd, struct filename *name, umode_t mode,
case 0: case S_IFREG:
error = vfs_create(idmap, path.dentry->d_inode,
dentry, mode, true);
- if (!error)
- ima_post_path_mknod(idmap, &path, dentry, mode,
- dev);
break;
case S_IFCHR: case S_IFBLK:
error = vfs_mknod(idmap, path.dentry->d_inode,
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 4b86c158ffb..50038722602 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -25,7 +25,6 @@
#include <linux/posix_acl_xattr.h>
#include <linux/xattr.h>
#include <linux/jhash.h>
-#include <linux/ima.h>
#include <linux/pagemap.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
@@ -858,12 +857,6 @@ __nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
goto out_nfserr;
}
- host_err = ima_file_check(file, may_flags);
- if (host_err) {
- fput(file);
- goto out_nfserr;
- }
-
if (may_flags & NFSD_MAY_64BIT_COOKIE)
file->f_mode |= FMODE_64BITHASH;
else
diff --git a/fs/open.c b/fs/open.c
index 4401a73d403..5d99c2bc061 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -29,7 +29,6 @@
#include <linux/audit.h>
#include <linux/falloc.h>
#include <linux/fs_struct.h>
-#include <linux/ima.h>
#include <linux/dnotify.h>
#include <linux/compat.h>
#include <linux/mnt_idmapping.h>
diff --git a/include/linux/ima.h b/include/linux/ima.h
index f56c6280667..6980e160ee5 100644
--- a/include/linux/ima.h
+++ b/include/linux/ima.h
@@ -16,26 +16,6 @@ struct linux_binprm;
#ifdef CONFIG_IMA
extern enum hash_algo ima_get_current_hash_algo(void);
-extern int ima_bprm_check(struct linux_binprm *bprm);
-extern int ima_file_check(struct file *file, int mask);
-extern void ima_post_create_tmpfile(struct mnt_idmap *idmap,
- struct inode *dir, struct dentry *dentry,
- umode_t mode);
-extern void ima_file_free(struct file *file);
-extern int ima_file_mmap(struct file *file, unsigned long reqprot,
- unsigned long prot, unsigned long flags);
-extern int ima_file_mprotect(struct vm_area_struct *vma, unsigned long reqprot,
- unsigned long prot);
-extern int ima_load_data(enum kernel_load_data_id id, bool contents);
-extern int ima_post_load_data(char *buf, loff_t size,
- enum kernel_load_data_id id, char *description);
-extern int ima_read_file(struct file *file, enum kernel_read_file_id id,
- bool contents);
-extern int ima_post_read_file(struct file *file, char *buf, loff_t size,
- enum kernel_read_file_id id);
-extern void ima_post_path_mknod(struct mnt_idmap *idmap,
- const struct path *dir, struct dentry *dentry,
- umode_t mode, unsigned int dev);
extern int ima_file_hash(struct file *file, char *buf, size_t buf_size);
extern int ima_inode_hash(struct inode *inode, char *buf, size_t buf_size);
extern void ima_kexec_cmdline(int kernel_fd, const void *buf, int size);
@@ -60,72 +40,6 @@ static inline enum hash_algo ima_get_current_hash_algo(void)
return HASH_ALGO__LAST;
}
-static inline int ima_bprm_check(struct linux_binprm *bprm)
-{
- return 0;
-}
-
-static inline int ima_file_check(struct file *file, int mask)
-{
- return 0;
-}
-
-static inline void ima_post_create_tmpfile(struct mnt_idmap *idmap,
- struct inode *dir,
- struct dentry *dentry,
- umode_t mode)
-{
-}
-
-static inline void ima_file_free(struct file *file)
-{
- return;
-}
-
-static inline int ima_file_mmap(struct file *file, unsigned long reqprot,
- unsigned long prot, unsigned long flags)
-{
- return 0;
-}
-
-static inline int ima_file_mprotect(struct vm_area_struct *vma,
- unsigned long reqprot, unsigned long prot)
-{
- return 0;
-}
-
-static inline int ima_load_data(enum kernel_load_data_id id, bool contents)
-{
- return 0;
-}
-
-static inline int ima_post_load_data(char *buf, loff_t size,
- enum kernel_load_data_id id,
- char *description)
-{
- return 0;
-}
-
-static inline int ima_read_file(struct file *file, enum kernel_read_file_id id,
- bool contents)
-{
- return 0;
-}
-
-static inline int ima_post_read_file(struct file *file, char *buf, loff_t size,
- enum kernel_read_file_id id)
-{
- return 0;
-}
-
-static inline void ima_post_path_mknod(struct mnt_idmap *idmap,
- const struct path *dir,
- struct dentry *dentry,
- umode_t mode, unsigned int dev)
-{
- return;
-}
-
static inline int ima_file_hash(struct file *file, char *buf, size_t buf_size)
{
return -EOPNOTSUPP;
@@ -176,20 +90,6 @@ static inline void ima_add_kexec_buffer(struct kimage *image)
{}
#endif
-#ifdef CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS
-extern void ima_post_key_create_or_update(struct key *keyring,
- struct key *key,
- const void *payload, size_t plen,
- unsigned long flags, bool create);
-#else
-static inline void ima_post_key_create_or_update(struct key *keyring,
- struct key *key,
- const void *payload,
- size_t plen,
- unsigned long flags,
- bool create) {}
-#endif /* CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS */
-
#ifdef CONFIG_IMA_APPRAISE
extern bool is_ima_appraise_enabled(void);
extern void ima_inode_post_setattr(struct mnt_idmap *idmap,
diff --git a/security/integrity/iint.c b/security/integrity/iint.c
index 8638976f799..bbadf974b31 100644
--- a/security/integrity/iint.c
+++ b/security/integrity/iint.c
@@ -172,19 +172,21 @@ static void init_once(void *foo)
mutex_init(&iint->mutex);
}
-static int __init integrity_iintcache_init(void)
+static int __init integrity_lsm_init(void)
{
iint_cache =
kmem_cache_create("iint_cache", sizeof(struct integrity_iint_cache),
0, SLAB_PANIC, init_once);
+
+ init_ima_lsm();
return 0;
}
DEFINE_LSM(integrity) = {
.name = "integrity",
- .init = integrity_iintcache_init,
+ .init = integrity_lsm_init,
+ .order = LSM_ORDER_LAST,
};
-
/*
* integrity_kernel_read - read data from the file
*
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index c29db699c99..7bdc7cdce07 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -127,6 +127,13 @@ void ima_load_kexec_buffer(void);
static inline void ima_load_kexec_buffer(void) {}
#endif /* CONFIG_HAVE_IMA_KEXEC */
+#ifdef CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS
+extern void ima_post_key_create_or_update(struct key *keyring,
+ struct key *key,
+ const void *payload, size_t plen,
+ unsigned long flags, bool create);
+#endif
+
/*
* The default binary_runtime_measurements list format is defined as the
* platform native format. The canonical format is defined as little-endian.
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index b7835e287d9..567b7af0f55 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -25,6 +25,7 @@
#include <linux/xattr.h>
#include <linux/ima.h>
#include <linux/iversion.h>
+#include <linux/lsm_hooks.h>
#include <linux/fs.h>
#include "ima.h"
@@ -184,7 +185,7 @@ static void ima_check_last_writer(struct integrity_iint_cache *iint,
*
* Flag files that changed, based on i_version
*/
-void ima_file_free(struct file *file)
+static void ima_file_free(struct file *file)
{
struct inode *inode = file_inode(file);
struct integrity_iint_cache *iint;
@@ -409,8 +410,8 @@ static int process_measurement(struct file *file, const struct cred *cred,
* On success return 0. On integrity appraisal error, assuming the file
* is in policy and IMA-appraisal is in enforcing mode, return -EACCES.
*/
-int ima_file_mmap(struct file *file, unsigned long reqprot,
- unsigned long prot, unsigned long flags)
+static int ima_file_mmap(struct file *file, unsigned long reqprot,
+ unsigned long prot, unsigned long flags)
{
u32 secid;
int ret;
@@ -448,8 +449,8 @@ int ima_file_mmap(struct file *file, unsigned long reqprot,
*
* On mprotect change success, return 0. On failure, return -EACESS.
*/
-int ima_file_mprotect(struct vm_area_struct *vma, unsigned long reqprot,
- unsigned long prot)
+static int ima_file_mprotect(struct vm_area_struct *vma, unsigned long reqprot,
+ unsigned long prot)
{
struct ima_template_desc *template = NULL;
struct file *file;
@@ -507,7 +508,7 @@ int ima_file_mprotect(struct vm_area_struct *vma, unsigned long reqprot,
* On success return 0. On integrity appraisal error, assuming the file
* is in policy and IMA-appraisal is in enforcing mode, return -EACCES.
*/
-int ima_bprm_check(struct linux_binprm *bprm)
+static int ima_bprm_check(struct linux_binprm *bprm)
{
int ret;
u32 secid;
@@ -669,9 +670,8 @@ EXPORT_SYMBOL_GPL(ima_inode_hash);
* Skip calling process_measurement(), but indicate which newly, created
* tmpfiles are in policy.
*/
-void ima_post_create_tmpfile(struct mnt_idmap *idmap,
- struct inode *dir, struct dentry *dentry,
- umode_t mode)
+static void ima_post_create_tmpfile(struct mnt_idmap *idmap, struct inode *dir,
+ struct dentry *dentry, umode_t mode)
{
struct integrity_iint_cache *iint;
struct inode *inode = dentry->d_inode;
@@ -706,9 +706,9 @@ void ima_post_create_tmpfile(struct mnt_idmap *idmap,
* Mark files created via the mknodat syscall as new, so that the
* file data can be written later.
*/
-void ima_post_path_mknod(struct mnt_idmap *idmap,
- const struct path *dir, struct dentry *dentry,
- umode_t mode, unsigned int dev)
+static void __maybe_unused
+ima_post_path_mknod(struct mnt_idmap *idmap, const struct path *dir,
+ struct dentry *dentry, umode_t mode, unsigned int dev)
{
struct integrity_iint_cache *iint;
struct inode *inode = dentry->d_inode;
@@ -747,8 +747,8 @@ void ima_post_path_mknod(struct mnt_idmap *idmap,
*
* For permission return 0, otherwise return -EACCES.
*/
-int ima_read_file(struct file *file, enum kernel_read_file_id read_id,
- bool contents)
+static int ima_read_file(struct file *file, enum kernel_read_file_id read_id,
+ bool contents)
{
enum ima_hooks func;
u32 secid;
@@ -797,8 +797,8 @@ const int read_idmap[READING_MAX_ID] = {
* On success return 0. On integrity appraisal error, assuming the file
* is in policy and IMA-appraisal is in enforcing mode, return -EACCES.
*/
-int ima_post_read_file(struct file *file, char *buf, loff_t size,
- enum kernel_read_file_id read_id)
+static int ima_post_read_file(struct file *file, char *buf, loff_t size,
+ enum kernel_read_file_id read_id)
{
enum ima_hooks func;
u32 secid;
@@ -831,7 +831,7 @@ int ima_post_read_file(struct file *file, char *buf, loff_t size,
*
* For permission return 0, otherwise return -EACCES.
*/
-int ima_load_data(enum kernel_load_data_id id, bool contents)
+static int ima_load_data(enum kernel_load_data_id id, bool contents)
{
bool ima_enforce, sig_enforce;
@@ -885,9 +885,9 @@ int ima_load_data(enum kernel_load_data_id id, bool contents)
* On success return 0. On integrity appraisal error, assuming the file
* is in policy and IMA-appraisal is in enforcing mode, return -EACCES.
*/
-int ima_post_load_data(char *buf, loff_t size,
- enum kernel_load_data_id load_id,
- char *description)
+static int ima_post_load_data(char *buf, loff_t size,
+ enum kernel_load_data_id load_id,
+ char *description)
{
if (load_id == LOADING_FIRMWARE) {
if ((ima_appraise & IMA_APPRAISE_FIRMWARE) &&
@@ -1116,4 +1116,28 @@ static int __init init_ima(void)
return error;
}
+static struct security_hook_list ima_hooks[] __lsm_ro_after_init = {
+ LSM_HOOK_INIT(bprm_check_security, ima_bprm_check),
+ LSM_HOOK_INIT(file_post_open, ima_file_check),
+ LSM_HOOK_INIT(inode_post_create_tmpfile, ima_post_create_tmpfile),
+ LSM_HOOK_INIT(file_pre_free_security, ima_file_free),
+ LSM_HOOK_INIT(mmap_file, ima_file_mmap),
+ LSM_HOOK_INIT(file_mprotect, ima_file_mprotect),
+ LSM_HOOK_INIT(kernel_load_data, ima_load_data),
+ LSM_HOOK_INIT(kernel_post_load_data, ima_post_load_data),
+ LSM_HOOK_INIT(kernel_read_file, ima_read_file),
+ LSM_HOOK_INIT(kernel_post_read_file, ima_post_read_file),
+#ifdef CONFIG_SECURITY_PATH
+ LSM_HOOK_INIT(path_post_mknod, ima_post_path_mknod),
+#endif
+#ifdef CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS
+ LSM_HOOK_INIT(key_post_create_or_update, ima_post_key_create_or_update),
+#endif
+};
+
+void __init init_ima_lsm(void)
+{
+ security_add_hooks(ima_hooks, ARRAY_SIZE(ima_hooks), "integrity");
+}
+
late_initcall(init_ima); /* Start IMA after the TPM is available */
diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h
index 7167a6e99bd..c72d375a356 100644
--- a/security/integrity/integrity.h
+++ b/security/integrity/integrity.h
@@ -191,6 +191,14 @@ extern struct dentry *integrity_dir;
struct modsig;
+#ifdef CONFIG_IMA
+void __init init_ima_lsm(void);
+#else
+static inline void __init init_ima_lsm(void)
+{
+}
+#endif
+
#ifdef CONFIG_INTEGRITY_SIGNATURE
int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
diff --git a/security/keys/key.c b/security/keys/key.c
index 0f9c6faf349..2acf9fa8073 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c
@@ -13,7 +13,6 @@
#include <linux/security.h>
#include <linux/workqueue.h>
#include <linux/random.h>
-#include <linux/ima.h>
#include <linux/err.h>
#include "internal.h"
@@ -936,8 +935,6 @@ static key_ref_t __key_create_or_update(key_ref_t keyring_ref,
security_key_post_create_or_update(keyring, key, payload, plen, flags,
true);
- ima_post_key_create_or_update(keyring, key, payload, plen,
- flags, true);
key_ref = make_key_ref(key, is_key_possessed(keyring_ref));
@@ -969,13 +966,9 @@ static key_ref_t __key_create_or_update(key_ref_t keyring_ref,
key_ref = __key_update(key_ref, &prep);
- if (!IS_ERR(key_ref)) {
+ if (!IS_ERR(key_ref))
security_key_post_create_or_update(keyring, key, payload, plen,
flags, false);
- ima_post_key_create_or_update(keyring, key,
- payload, plen,
- flags, false);
- }
goto error_free_prep;
}
diff --git a/security/security.c b/security/security.c
index 24f52ba3218..5ca8d89eb57 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1097,12 +1097,7 @@ int security_bprm_creds_from_file(struct linux_binprm *bprm, struct file *file)
*/
int security_bprm_check(struct linux_binprm *bprm)
{
- int ret;
-
- ret = call_int_hook(bprm_check_security, 0, bprm);
- if (ret)
- return ret;
- return ima_bprm_check(bprm);
+ return call_int_hook(bprm_check_security, 0, bprm);
}
/**
@@ -2849,13 +2844,8 @@ static inline unsigned long mmap_prot(struct file *file, unsigned long prot)
int security_mmap_file(struct file *file, unsigned long prot,
unsigned long flags)
{
- unsigned long prot_adj = mmap_prot(file, prot);
- int ret;
-
- ret = call_int_hook(mmap_file, 0, file, prot, prot_adj, flags);
- if (ret)
- return ret;
- return ima_file_mmap(file, prot, prot_adj, flags);
+ return call_int_hook(mmap_file, 0, file, prot, mmap_prot(file, prot),
+ flags);
}
/**
@@ -2884,12 +2874,7 @@ int security_mmap_addr(unsigned long addr)
int security_file_mprotect(struct vm_area_struct *vma, unsigned long reqprot,
unsigned long prot)
{
- int ret;
-
- ret = call_int_hook(file_mprotect, 0, vma, reqprot, prot);
- if (ret)
- return ret;
- return ima_file_mprotect(vma, reqprot, prot);
+ return call_int_hook(file_mprotect, 0, vma, reqprot, prot);
}
/**
@@ -3219,12 +3204,7 @@ int security_kernel_module_request(char *kmod_name)
int security_kernel_read_file(struct file *file, enum kernel_read_file_id id,
bool contents)
{
- int ret;
-
- ret = call_int_hook(kernel_read_file, 0, file, id, contents);
- if (ret)
- return ret;
- return ima_read_file(file, id, contents);
+ return call_int_hook(kernel_read_file, 0, file, id, contents);
}
EXPORT_SYMBOL_GPL(security_kernel_read_file);
@@ -3244,12 +3224,7 @@ EXPORT_SYMBOL_GPL(security_kernel_read_file);
int security_kernel_post_read_file(struct file *file, char *buf, loff_t size,
enum kernel_read_file_id id)
{
- int ret;
-
- ret = call_int_hook(kernel_post_read_file, 0, file, buf, size, id);
- if (ret)
- return ret;
- return ima_post_read_file(file, buf, size, id);
+ return call_int_hook(kernel_post_read_file, 0, file, buf, size, id);
}
EXPORT_SYMBOL_GPL(security_kernel_post_read_file);
@@ -3264,12 +3239,7 @@ EXPORT_SYMBOL_GPL(security_kernel_post_read_file);
*/
int security_kernel_load_data(enum kernel_load_data_id id, bool contents)
{
- int ret;
-
- ret = call_int_hook(kernel_load_data, 0, id, contents);
- if (ret)
- return ret;
- return ima_load_data(id, contents);
+ return call_int_hook(kernel_load_data, 0, id, contents);
}
EXPORT_SYMBOL_GPL(security_kernel_load_data);
@@ -3291,13 +3261,8 @@ int security_kernel_post_load_data(char *buf, loff_t size,
enum kernel_load_data_id id,
char *description)
{
- int ret;
-
- ret = call_int_hook(kernel_post_load_data, 0, buf, size, id,
- description);
- if (ret)
- return ret;
- return ima_post_load_data(buf, size, id, description);
+ return call_int_hook(kernel_post_load_data, 0, buf, size, id,
+ description);
}
EXPORT_SYMBOL_GPL(security_kernel_post_load_data);
--
2.25.1
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