[v8,19/24] ima: Move to LSM infrastructure

Message ID 20231214170834.3324559-20-roberto.sassu@huaweicloud.com
State New
Headers
Series security: Move IMA and EVM to the LSM infrastructure |

Commit Message

Roberto Sassu Dec. 14, 2023, 5:08 p.m. UTC
  From: Roberto Sassu <roberto.sassu@huawei.com>

Move hardcoded IMA function calls (not appraisal-specific functions) from
various places in the kernel to the LSM infrastructure, by introducing a
new LSM named 'ima' (at the end of the LSM list and always enabled like
'integrity').

Having IMA before EVM in the Makefile is sufficient to preserve the
relative order of the new 'ima' LSM in respect to the upcoming 'evm' LSM,
and thus the order of IMA and EVM function calls as when they were
hardcoded.

Make moved functions as static (except 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().

A slight difference is that IMA and EVM functions registered for the
inode_post_setattr, inode_post_removexattr, path_post_mknod,
inode_post_create_tmpfile, inode_post_set_acl and inode_post_remove_acl
won't be executed for private inodes. Since those inodes are supposed to be
fs-internal, they should not be of interest of IMA or EVM. The S_PRIVATE
flag is used for anonymous inodes, hugetlbfs, reiserfs xattrs, XFS scrub
and kernel-internal tmpfs files.

Conditionally register ima_post_path_mknod() if CONFIG_SECURITY_PATH is
enabled, otherwise the path_post_mknod hook won't be available.

Also, conditionally register ima_post_key_create_or_update() if
CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS is enabled.

Move integrity_kernel_module_request() to IMA and name it
ima_kernel_module_request(), as only appraisal is affected by the crypto
subsystem trying to load kernel modules. Conditionally register
ima_kernel_module_request() if CONFIG_INTEGRITY_ASYMMETRIC_KEYS is
enabled.

Finally, add the LSM_ID_IMA case in lsm_list_modules_test.c.

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Acked-by: Chuck Lever <chuck.lever@oracle.com>
---
 fs/file_table.c                               |   2 -
 fs/namei.c                                    |   6 --
 fs/nfsd/vfs.c                                 |   7 --
 fs/open.c                                     |   1 -
 include/linux/ima.h                           |  94 ----------------
 include/linux/integrity.h                     |  13 ---
 include/uapi/linux/lsm.h                      |   1 +
 security/integrity/Makefile                   |   1 +
 security/integrity/digsig_asymmetric.c        |  23 ----
 security/integrity/ima/ima.h                  |   6 ++
 security/integrity/ima/ima_main.c             | 102 ++++++++++++++----
 security/integrity/integrity.h                |   1 +
 security/keys/key.c                           |   9 +-
 security/security.c                           |  63 +++--------
 .../selftests/lsm/lsm_list_modules_test.c     |   3 +
 15 files changed, 107 insertions(+), 225 deletions(-)
  

Comments

Mimi Zohar Dec. 26, 2023, 6:14 p.m. UTC | #1
On Thu, 2023-12-14 at 18:08 +0100, Roberto Sassu wrote:
> From: Roberto Sassu <roberto.sassu@huawei.com>
> 
> Move hardcoded IMA function calls (not appraisal-specific functions) from
> various places in the kernel to the LSM infrastructure, by introducing a
> new LSM named 'ima' (at the end of the LSM list and always enabled like
> 'integrity').
> 
> Having IMA before EVM in the Makefile is sufficient to preserve the
> relative order of the new 'ima' LSM in respect to the upcoming 'evm' LSM,
> and thus the order of IMA and EVM function calls as when they were
> hardcoded.
> 
> Make moved functions as static (except 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().
> 
> A slight difference is that IMA and EVM functions registered for the
> inode_post_setattr, inode_post_removexattr, path_post_mknod,
> inode_post_create_tmpfile, inode_post_set_acl and inode_post_remove_acl
> won't be executed for private inodes. Since those inodes are supposed to be
> fs-internal, they should not be of interest of IMA or EVM. The S_PRIVATE
> flag is used for anonymous inodes, hugetlbfs, reiserfs xattrs, XFS scrub
> and kernel-internal tmpfs files.
> 
> Conditionally register ima_post_path_mknod() if CONFIG_SECURITY_PATH is
> enabled, otherwise the path_post_mknod hook won't be available.

Up to this point, enabling CONFIG_SECURITY_PATH was not required.  By
making it conditional on CONFIG_SECURITY_PATH, anyone enabling IMA will
also need to enable CONFIG_SECURITY_PATH.  Without it, new files will
not be tagged as a "new" file.

Casey, Paul, how common is it today not to enable CONFIG_SECURITY_PATH?
Will enabling it just for IMA be a problem?

> 
> Also, conditionally register ima_post_key_create_or_update() if
> CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS is enabled.
> 
> Move integrity_kernel_module_request() to IMA and name it
> ima_kernel_module_request(), as only appraisal is affected by the crypto
> subsystem trying to load kernel modules. Conditionally register
> ima_kernel_module_request() if CONFIG_INTEGRITY_ASYMMETRIC_KEYS is
> enabled.

The previous version was so clean. 
Moving integrity_kernel_module_request() to IMA should be a separate
patch, probably a prereq.  Then like the other functions convert it to
an LSM hook.

Please include a line explaning why the original EVM signature is not
affected.

> 
> Finally, add the LSM_ID_IMA case in lsm_list_modules_test.c.
> 
> Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
> Acked-by: Chuck Lever <chuck.lever@oracle.com>
  
Casey Schaufler Dec. 26, 2023, 8:14 p.m. UTC | #2
On 12/26/2023 10:14 AM, Mimi Zohar wrote:
> On Thu, 2023-12-14 at 18:08 +0100, Roberto Sassu wrote:
>> From: Roberto Sassu <roberto.sassu@huawei.com>
>>
>> Move hardcoded IMA function calls (not appraisal-specific functions) from
>> various places in the kernel to the LSM infrastructure, by introducing a
>> new LSM named 'ima' (at the end of the LSM list and always enabled like
>> 'integrity').
>>
>> Having IMA before EVM in the Makefile is sufficient to preserve the
>> relative order of the new 'ima' LSM in respect to the upcoming 'evm' LSM,
>> and thus the order of IMA and EVM function calls as when they were
>> hardcoded.
>>
>> Make moved functions as static (except 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().
>>
>> A slight difference is that IMA and EVM functions registered for the
>> inode_post_setattr, inode_post_removexattr, path_post_mknod,
>> inode_post_create_tmpfile, inode_post_set_acl and inode_post_remove_acl
>> won't be executed for private inodes. Since those inodes are supposed to be
>> fs-internal, they should not be of interest of IMA or EVM. The S_PRIVATE
>> flag is used for anonymous inodes, hugetlbfs, reiserfs xattrs, XFS scrub
>> and kernel-internal tmpfs files.
>>
>> Conditionally register ima_post_path_mknod() if CONFIG_SECURITY_PATH is
>> enabled, otherwise the path_post_mknod hook won't be available.
> Up to this point, enabling CONFIG_SECURITY_PATH was not required.  By
> making it conditional on CONFIG_SECURITY_PATH, anyone enabling IMA will
> also need to enable CONFIG_SECURITY_PATH.  Without it, new files will
> not be tagged as a "new" file.
>
> Casey, Paul, how common is it today not to enable CONFIG_SECURITY_PATH?
> Will enabling it just for IMA be a problem?

Landlock, AppArmor and TOMOYO require it. Fedora enables Landlock and Ubuntu
enables AppArmor. I expect that, except for "minimal" distributions, you
won't get any push back. If a distribution is striving for minimal, it's not
going to use IMA.

It makes me wonder if eliminating CONFIG_SECURITY_PATH might not be a
rational alternative.
  
Mimi Zohar Dec. 27, 2023, 7:52 p.m. UTC | #3
On Tue, 2023-12-26 at 12:14 -0800, Casey Schaufler wrote:
> On 12/26/2023 10:14 AM, Mimi Zohar wrote:
> > On Thu, 2023-12-14 at 18:08 +0100, Roberto Sassu wrote:
> >> From: Roberto Sassu <roberto.sassu@huawei.com>
> >>
> >> Move hardcoded IMA function calls (not appraisal-specific functions) from
> >> various places in the kernel to the LSM infrastructure, by introducing a
> >> new LSM named 'ima' (at the end of the LSM list and always enabled like
> >> 'integrity').
> >>
> >> Having IMA before EVM in the Makefile is sufficient to preserve the
> >> relative order of the new 'ima' LSM in respect to the upcoming 'evm' LSM,
> >> and thus the order of IMA and EVM function calls as when they were
> >> hardcoded.
> >>
> >> Make moved functions as static (except 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().
> >>
> >> A slight difference is that IMA and EVM functions registered for the
> >> inode_post_setattr, inode_post_removexattr, path_post_mknod,
> >> inode_post_create_tmpfile, inode_post_set_acl and inode_post_remove_acl
> >> won't be executed for private inodes. Since those inodes are supposed to be
> >> fs-internal, they should not be of interest of IMA or EVM. The S_PRIVATE
> >> flag is used for anonymous inodes, hugetlbfs, reiserfs xattrs, XFS scrub
> >> and kernel-internal tmpfs files.
> >>
> >> Conditionally register ima_post_path_mknod() if CONFIG_SECURITY_PATH is
> >> enabled, otherwise the path_post_mknod hook won't be available.
> > Up to this point, enabling CONFIG_SECURITY_PATH was not required.  By
> > making it conditional on CONFIG_SECURITY_PATH, anyone enabling IMA will
> > also need to enable CONFIG_SECURITY_PATH.  Without it, new files will
> > not be tagged as a "new" file.
> >
> > Casey, Paul, how common is it today not to enable CONFIG_SECURITY_PATH?
> > Will enabling it just for IMA be a problem?
> 
> Landlock, AppArmor and TOMOYO require it. Fedora enables Landlock and Ubuntu
> enables AppArmor. I expect that, except for "minimal" distributions, you
> won't get any push back. If a distribution is striving for minimal, it's not
> going to use IMA.
> 
> It makes me wonder if eliminating CONFIG_SECURITY_PATH might not be a
> rational alternative.

Embedded systems were the first to use IMA for file signature
verification, not distros.               Could they have enabled
SELinux, lockdown, and IMA?

Mimi
  
Casey Schaufler Dec. 27, 2023, 8:20 p.m. UTC | #4
On 12/27/2023 11:52 AM, Mimi Zohar wrote:
> On Tue, 2023-12-26 at 12:14 -0800, Casey Schaufler wrote:
>> On 12/26/2023 10:14 AM, Mimi Zohar wrote:
>>> On Thu, 2023-12-14 at 18:08 +0100, Roberto Sassu wrote:
>>>> From: Roberto Sassu <roberto.sassu@huawei.com>
>>>>
>>>> Move hardcoded IMA function calls (not appraisal-specific functions) from
>>>> various places in the kernel to the LSM infrastructure, by introducing a
>>>> new LSM named 'ima' (at the end of the LSM list and always enabled like
>>>> 'integrity').
>>>>
>>>> Having IMA before EVM in the Makefile is sufficient to preserve the
>>>> relative order of the new 'ima' LSM in respect to the upcoming 'evm' LSM,
>>>> and thus the order of IMA and EVM function calls as when they were
>>>> hardcoded.
>>>>
>>>> Make moved functions as static (except 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().
>>>>
>>>> A slight difference is that IMA and EVM functions registered for the
>>>> inode_post_setattr, inode_post_removexattr, path_post_mknod,
>>>> inode_post_create_tmpfile, inode_post_set_acl and inode_post_remove_acl
>>>> won't be executed for private inodes. Since those inodes are supposed to be
>>>> fs-internal, they should not be of interest of IMA or EVM. The S_PRIVATE
>>>> flag is used for anonymous inodes, hugetlbfs, reiserfs xattrs, XFS scrub
>>>> and kernel-internal tmpfs files.
>>>>
>>>> Conditionally register ima_post_path_mknod() if CONFIG_SECURITY_PATH is
>>>> enabled, otherwise the path_post_mknod hook won't be available.
>>> Up to this point, enabling CONFIG_SECURITY_PATH was not required.  By
>>> making it conditional on CONFIG_SECURITY_PATH, anyone enabling IMA will
>>> also need to enable CONFIG_SECURITY_PATH.  Without it, new files will
>>> not be tagged as a "new" file.
>>>
>>> Casey, Paul, how common is it today not to enable CONFIG_SECURITY_PATH?
>>> Will enabling it just for IMA be a problem?
>> Landlock, AppArmor and TOMOYO require it. Fedora enables Landlock and Ubuntu
>> enables AppArmor. I expect that, except for "minimal" distributions, you
>> won't get any push back. If a distribution is striving for minimal, it's not
>> going to use IMA.
>>
>> It makes me wonder if eliminating CONFIG_SECURITY_PATH might not be a
>> rational alternative.
> Embedded systems were the first to use IMA for file signature
> verification, not distros.               Could they have enabled
> SELinux, lockdown, and IMA?

Yes, they could have. I know some have used Smack and some SELinux.
That's not really relevant, as neither of those use path hooks. My
thought is that CONFIG_SECURITY_PATH adds more aggravation than value,
but I can't quote numbers on either. I don't see a problem with IMA
using path hooks. I also wouldn't see harm in moving the hook(s) you
need for IMA out from that configuration option and into the general
set. With the current rate of new hook additions I can't see moving
an existing hook as a problem.
  

Patch

diff --git a/fs/file_table.c b/fs/file_table.c
index c72dc75f2bd3..0401ac98281c 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>
 
@@ -386,7 +385,6 @@  static void __fput(struct file *file)
 	locks_remove_file(file);
 
 	security_file_release(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 adb3ab27951a..37cc0988308f 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>
@@ -3622,8 +3621,6 @@  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)) {
@@ -3687,7 +3684,6 @@  static int vfs_tmpfile(struct mnt_idmap *idmap,
 		spin_unlock(&inode->i_lock);
 	}
 	security_inode_post_create_tmpfile(idmap, inode);
-	ima_post_create_tmpfile(idmap, inode);
 	return 0;
 }
 
@@ -4036,8 +4032,6 @@  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, dentry);
 			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 b0c3f07a8bba..e491392a1243 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>
@@ -883,12 +882,6 @@  __nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
 		goto out;
 	}
 
-	host_err = ima_file_check(file, may_flags);
-	if (host_err) {
-		fput(file);
-		goto out;
-	}
-
 	if (may_flags & NFSD_MAY_64BIT_COOKIE)
 		file->f_mode |= FMODE_64BITHASH;
 	else
diff --git a/fs/open.c b/fs/open.c
index 02dc608d40d8..c8bb9bd5259f 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 31ef6c3c3207..23ae24b60ecf 100644
--- a/include/linux/ima.h
+++ b/include/linux/ima.h
@@ -16,24 +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 *inode);
-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,
-				struct dentry *dentry);
 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);
@@ -58,68 +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 *inode)
-{
-}
-
-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,
-				       struct dentry *dentry)
-{
-	return;
-}
-
 static inline int ima_file_hash(struct file *file, char *buf, size_t buf_size)
 {
 	return -EOPNOTSUPP;
@@ -170,20 +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/include/linux/integrity.h b/include/linux/integrity.h
index 2ea0f2f65ab6..ef0f63ef5ebc 100644
--- a/include/linux/integrity.h
+++ b/include/linux/integrity.h
@@ -42,17 +42,4 @@  static inline void integrity_load_keys(void)
 }
 #endif /* CONFIG_INTEGRITY */
 
-#ifdef CONFIG_INTEGRITY_ASYMMETRIC_KEYS
-
-extern int integrity_kernel_module_request(char *kmod_name);
-
-#else
-
-static inline int integrity_kernel_module_request(char *kmod_name)
-{
-	return 0;
-}
-
-#endif /* CONFIG_INTEGRITY_ASYMMETRIC_KEYS */
-
 #endif /* _LINUX_INTEGRITY_H */
diff --git a/include/uapi/linux/lsm.h b/include/uapi/linux/lsm.h
index f0386880a78e..ee7d034255a9 100644
--- a/include/uapi/linux/lsm.h
+++ b/include/uapi/linux/lsm.h
@@ -61,6 +61,7 @@  struct lsm_ctx {
 #define LSM_ID_LOCKDOWN		108
 #define LSM_ID_BPF		109
 #define LSM_ID_LANDLOCK		110
+#define LSM_ID_IMA		111
 
 /*
  * LSM_ATTR_XXX definitions identify different LSM attributes
diff --git a/security/integrity/Makefile b/security/integrity/Makefile
index d0ffe37dc1d6..92b63039c654 100644
--- a/security/integrity/Makefile
+++ b/security/integrity/Makefile
@@ -18,5 +18,6 @@  integrity-$(CONFIG_LOAD_IPL_KEYS) += platform_certs/load_ipl_s390.o
 integrity-$(CONFIG_LOAD_PPC_KEYS) += platform_certs/efi_parser.o \
                                      platform_certs/load_powerpc.o \
                                      platform_certs/keyring_handler.o
+# The relative order of the 'ima' and 'evm' LSMs depends on the order below.
 obj-$(CONFIG_IMA)			+= ima/
 obj-$(CONFIG_EVM)			+= evm/
diff --git a/security/integrity/digsig_asymmetric.c b/security/integrity/digsig_asymmetric.c
index 895f4b9ce8c6..de603cf42ac7 100644
--- a/security/integrity/digsig_asymmetric.c
+++ b/security/integrity/digsig_asymmetric.c
@@ -132,26 +132,3 @@  int asymmetric_verify(struct key *keyring, const char *sig,
 	pr_debug("%s() = %d\n", __func__, ret);
 	return ret;
 }
-
-/**
- * integrity_kernel_module_request - prevent crypto-pkcs1pad(rsa,*) requests
- * @kmod_name: kernel module name
- *
- * We have situation, when public_key_verify_signature() in case of RSA
- * algorithm use alg_name to store internal information in order to
- * construct an algorithm on the fly, but crypto_larval_lookup() will try
- * to use alg_name in order to load kernel module with same name.
- * Since we don't have any real "crypto-pkcs1pad(rsa,*)" kernel modules,
- * we are safe to fail such module request from crypto_larval_lookup().
- *
- * In this way we prevent modprobe execution during digsig verification
- * and avoid possible deadlock if modprobe and/or it's dependencies
- * also signed with digsig.
- */
-int integrity_kernel_module_request(char *kmod_name)
-{
-	if (strncmp(kmod_name, "crypto-pkcs1pad(rsa,", 20) == 0)
-		return -EINVAL;
-
-	return 0;
-}
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index c29db699c996..c0412100023e 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -127,6 +127,12 @@  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
+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 02021ee467d3..fa6bfe9155ba 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -189,7 +189,7 @@  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;
@@ -427,8 +427,8 @@  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;
@@ -466,8 +466,8 @@  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;
@@ -525,7 +525,7 @@  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;
@@ -551,7 +551,7 @@  int ima_bprm_check(struct linux_binprm *bprm)
  * 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_check(struct file *file, int mask)
+static int ima_file_check(struct file *file, int mask)
 {
 	u32 secid;
 
@@ -560,7 +560,6 @@  int ima_file_check(struct file *file, int mask)
 				   mask & (MAY_READ | MAY_WRITE | MAY_EXEC |
 					   MAY_APPEND), FILE_CHECK);
 }
-EXPORT_SYMBOL_GPL(ima_file_check);
 
 static int __ima_inode_hash(struct inode *inode, struct file *file, char *buf,
 			    size_t buf_size)
@@ -685,8 +684,9 @@  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 *inode)
+static void ima_post_create_tmpfile(struct mnt_idmap *idmap,
+				    struct inode *inode)
+
 {
 	struct integrity_iint_cache *iint;
 	int must_appraise;
@@ -717,8 +717,8 @@  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,
-			 struct dentry *dentry)
+static void __maybe_unused
+ima_post_path_mknod(struct mnt_idmap *idmap, struct dentry *dentry)
 {
 	struct integrity_iint_cache *iint;
 	struct inode *inode = dentry->d_inode;
@@ -753,8 +753,8 @@  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;
@@ -803,8 +803,8 @@  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;
@@ -837,7 +837,7 @@  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;
 
@@ -891,9 +891,9 @@  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) &&
@@ -1122,4 +1122,66 @@  static int __init init_ima(void)
 	return error;
 }
 
+/**
+ * ima_kernel_module_request - prevent crypto-pkcs1pad(rsa,*) requests
+ * @kmod_name: kernel module name
+ *
+ * We have situation, when public_key_verify_signature() in case of RSA
+ * algorithm use alg_name to store internal information in order to
+ * construct an algorithm on the fly, but crypto_larval_lookup() will try
+ * to use alg_name in order to load kernel module with same name.
+ * Since we don't have any real "crypto-pkcs1pad(rsa,*)" kernel modules,
+ * we are safe to fail such module request from crypto_larval_lookup().
+ *
+ * In this way we prevent modprobe execution during digsig verification
+ * and avoid possible deadlock if modprobe and/or it's dependencies
+ * also signed with digsig.
+ */
+static int __maybe_unused ima_kernel_module_request(char *kmod_name)
+{
+	if (strncmp(kmod_name, "crypto-pkcs1pad(rsa,", 20) == 0)
+		return -EINVAL;
+
+	return 0;
+}
+
+static struct security_hook_list ima_hooks[] __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_release, 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
+#ifdef CONFIG_INTEGRITY_ASYMMETRIC_KEYS
+	LSM_HOOK_INIT(kernel_module_request, ima_kernel_module_request),
+#endif
+};
+
+static const struct lsm_id ima_lsmid = {
+	.name = "ima",
+	.id = LSM_ID_IMA,
+};
+
+static int __init init_ima_lsm(void)
+{
+	security_add_hooks(ima_hooks, ARRAY_SIZE(ima_hooks), &ima_lsmid);
+	return 0;
+}
+
+DEFINE_LSM(ima) = {
+	.name = "ima",
+	.init = init_ima_lsm,
+	.order = LSM_ORDER_LAST,
+};
+
 late_initcall(init_ima);	/* Start IMA after the TPM is available */
diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h
index 9561db7cf6b4..59eaddd84434 100644
--- a/security/integrity/integrity.h
+++ b/security/integrity/integrity.h
@@ -18,6 +18,7 @@ 
 #include <crypto/hash.h>
 #include <linux/key.h>
 #include <linux/audit.h>
+#include <linux/lsm_hooks.h>
 
 /* iint action cache flags */
 #define IMA_MEASURE		0x00000001
diff --git a/security/keys/key.c b/security/keys/key.c
index f75fe66c2f03..80fc2f203a0c 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"
 
@@ -937,8 +936,6 @@  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));
 
@@ -970,13 +967,9 @@  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 423d53092604..e18953ee4a97 100644
--- a/security/security.c
+++ b/security/security.c
@@ -50,7 +50,8 @@ 
 	(IS_ENABLED(CONFIG_SECURITY_SAFESETID) ? 1 : 0) + \
 	(IS_ENABLED(CONFIG_SECURITY_LOCKDOWN_LSM) ? 1 : 0) + \
 	(IS_ENABLED(CONFIG_BPF_LSM) ? 1 : 0) + \
-	(IS_ENABLED(CONFIG_SECURITY_LANDLOCK) ? 1 : 0))
+	(IS_ENABLED(CONFIG_SECURITY_LANDLOCK) ? 1 : 0) + \
+	(IS_ENABLED(CONFIG_IMA) ? 1 : 0))
 
 /*
  * These are descriptions of the reasons that can be passed to the
@@ -1182,12 +1183,7 @@  int security_bprm_creds_from_file(struct linux_binprm *bprm, const struct 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);
 }
 
 /**
@@ -2883,13 +2879,8 @@  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);
 }
 
 /**
@@ -2918,12 +2909,7 @@  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);
 }
 
 /**
@@ -3232,12 +3218,7 @@  int security_kernel_create_files_as(struct cred *new, struct inode *inode)
  */
 int security_kernel_module_request(char *kmod_name)
 {
-	int ret;
-
-	ret = call_int_hook(kernel_module_request, 0, kmod_name);
-	if (ret)
-		return ret;
-	return integrity_kernel_module_request(kmod_name);
+	return call_int_hook(kernel_module_request, 0, kmod_name);
 }
 
 /**
@@ -3253,12 +3234,7 @@  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);
 
@@ -3278,12 +3254,7 @@  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);
 
@@ -3298,12 +3269,7 @@  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);
 
@@ -3325,13 +3291,8 @@  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);
 
diff --git a/tools/testing/selftests/lsm/lsm_list_modules_test.c b/tools/testing/selftests/lsm/lsm_list_modules_test.c
index 9df29b1e3497..17333787cb2f 100644
--- a/tools/testing/selftests/lsm/lsm_list_modules_test.c
+++ b/tools/testing/selftests/lsm/lsm_list_modules_test.c
@@ -122,6 +122,9 @@  TEST(correct_lsm_list_modules)
 		case LSM_ID_LANDLOCK:
 			name = "landlock";
 			break;
+		case LSM_ID_IMA:
+			name = "ima";
+			break;
 		default:
 			name = "INVALID";
 			break;