[PATCH v4 31/34] ima,evm: move initcalls to the LSM framework

[Paul Moore]

On Tue, Sep 16, 2025 at 6:14 PM Paul Moore <paul at paul-moore.com> wrote:
>
> From: Roberto Sassu <roberto.sassu at huawei.com>
>
> This patch converts IMA and EVM to use the LSM frameworks's initcall
> mechanism. It moved the integrity_fs_init() call to ima_fs_init() and
> evm_init_secfs(), to work around the fact that there is no "integrity" LSM,
> and introduced integrity_fs_fini() to remove the integrity directory, if
> empty. Both integrity_fs_init() and integrity_fs_fini() support the
> scenario of being called by both the IMA and EVM LSMs.
>
> This patch does not touch any of the platform certificate code that
> lives under the security/integrity/platform_certs directory as the
> IMA/EVM developers would prefer to address that in a future patchset.
>
> Signed-off-by: Roberto Sassu <roberto.sassu at huawei.com>
> [PM: adjust description as discussed over email]
> Signed-off-by: Paul Moore <paul at paul-moore.com>
> ---
>  security/integrity/evm/evm_main.c  |  3 +--
>  security/integrity/evm/evm_secfs.c | 11 +++++++++--
>  security/integrity/iint.c          | 14 ++++++++++++--
>  security/integrity/ima/ima_fs.c    | 11 +++++++++--
>  security/integrity/ima/ima_main.c  |  4 ++--
>  security/integrity/integrity.h     |  2 ++
>  6 files changed, 35 insertions(+), 10 deletions(-)

I appreciate you reviewing most (all?) of the other patches in this
patchset, but any chance you could review the IMA/EVM from Roberto?
This is the only patch that really needs your review ...

> diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c
> index db8e324ed4e6..73d500a375cb 100644
> --- a/security/integrity/evm/evm_main.c
> +++ b/security/integrity/evm/evm_main.c
> @@ -1179,6 +1179,5 @@ DEFINE_LSM(evm) = {
>         .init = init_evm_lsm,
>         .order = LSM_ORDER_LAST,
>         .blobs = &evm_blob_sizes,
> +       .initcall_late = init_evm,
>  };
> -
> -late_initcall(init_evm);
> diff --git a/security/integrity/evm/evm_secfs.c b/security/integrity/evm/evm_secfs.c
> index b0d2aad27850..c26724690cec 100644
> --- a/security/integrity/evm/evm_secfs.c
> +++ b/security/integrity/evm/evm_secfs.c
> @@ -302,10 +302,16 @@ int __init evm_init_secfs(void)
>         int error = 0;
>         struct dentry *dentry;
>
> -       evm_dir = securityfs_create_dir("evm", integrity_dir);
> -       if (IS_ERR(evm_dir))
> +       error = integrity_fs_init();
> +       if (error < 0)
>                 return -EFAULT;
>
> +       evm_dir = securityfs_create_dir("evm", integrity_dir);
> +       if (IS_ERR(evm_dir)) {
> +               error = -EFAULT;
> +               goto out;
> +       }
> +
>         dentry = securityfs_create_file("evm", 0660,
>                                       evm_dir, NULL, &evm_key_ops);
>         if (IS_ERR(dentry)) {
> @@ -329,5 +335,6 @@ int __init evm_init_secfs(void)
>  out:
>         securityfs_remove(evm_symlink);
>         securityfs_remove(evm_dir);
> +       integrity_fs_fini();
>         return error;
>  }
> diff --git a/security/integrity/iint.c b/security/integrity/iint.c
> index 068ac6c2ae1e..8ec1a3436a71 100644
> --- a/security/integrity/iint.c
> +++ b/security/integrity/iint.c
> @@ -42,8 +42,11 @@ void __init integrity_load_keys(void)
>                 evm_load_x509();
>  }
>
> -static int __init integrity_fs_init(void)
> +int __init integrity_fs_init(void)
>  {
> +       if (integrity_dir)
> +               return 0;
> +
>         integrity_dir = securityfs_create_dir("integrity", NULL);
>         if (IS_ERR(integrity_dir)) {
>                 int ret = PTR_ERR(integrity_dir);
> @@ -58,4 +61,11 @@ static int __init integrity_fs_init(void)
>         return 0;
>  }
>
> -late_initcall(integrity_fs_init)
> +void __init integrity_fs_fini(void)
> +{
> +       if (!integrity_dir || !simple_empty(integrity_dir))
> +               return;
> +
> +       securityfs_remove(integrity_dir);
> +       integrity_dir = NULL;
> +}
> diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c
> index 87045b09f120..012a58959ff0 100644
> --- a/security/integrity/ima/ima_fs.c
> +++ b/security/integrity/ima/ima_fs.c
> @@ -499,9 +499,15 @@ int __init ima_fs_init(void)
>         struct dentry *dentry;
>         int ret;
>
> +       ret = integrity_fs_init();
> +       if (ret < 0)
> +               return ret;
> +
>         ima_dir = securityfs_create_dir("ima", integrity_dir);
> -       if (IS_ERR(ima_dir))
> -               return PTR_ERR(ima_dir);
> +       if (IS_ERR(ima_dir)) {
> +               ret = PTR_ERR(ima_dir);
> +               goto out;
> +       }
>
>         ima_symlink = securityfs_create_symlink("ima", NULL, "integrity/ima",
>                                                 NULL);
> @@ -555,6 +561,7 @@ int __init ima_fs_init(void)
>  out:
>         securityfs_remove(ima_symlink);
>         securityfs_remove(ima_dir);
> +       integrity_fs_fini();
>
>         return ret;
>  }
> diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
> index eade8e1e3cb1..b703bfc2f470 100644
> --- a/security/integrity/ima/ima_main.c
> +++ b/security/integrity/ima/ima_main.c
> @@ -1283,6 +1283,6 @@ DEFINE_LSM(ima) = {
>         .init = init_ima_lsm,
>         .order = LSM_ORDER_LAST,
>         .blobs = &ima_blob_sizes,
> +       /* Start IMA after the TPM is available */
> +       .initcall_late = init_ima,
>  };
> -
> -late_initcall(init_ima);       /* Start IMA after the TPM is available */
> diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h
> index c2c2da691123..7b388b66cf80 100644
> --- a/security/integrity/integrity.h
> +++ b/security/integrity/integrity.h
> @@ -114,6 +114,8 @@ struct ima_file_id {
>
>  int integrity_kernel_read(struct file *file, loff_t offset,
>                           void *addr, unsigned long count);
> +int __init integrity_fs_init(void);
> +void __init integrity_fs_fini(void);
>
>  #define INTEGRITY_KEYRING_EVM          0
>  #define INTEGRITY_KEYRING_IMA          1
> --
> 2.51.0

-- 
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