Re: [PATCH v2 21/25] ima: Move to LSM infrastructure
From: Chuck Lever
Date: Thu Aug 31 2023 - 10:16:48 EST
On Thu, Aug 31, 2023 at 01:37:59PM +0200, Roberto Sassu wrote:
> From: Roberto Sassu <roberto.sassu@xxxxxxxxxx>
>
> 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().
>
> Signed-off-by: Roberto Sassu <roberto.sassu@xxxxxxxxxx>
> ---
> fs/file_table.c | 2 -
> fs/namei.c | 7 ---
> fs/nfsd/vfs.c | 7 ---
For the NFSD part:
Acked-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
> fs/open.c | 1 -
> include/linux/ima.h | 94 -------------------------------
> security/integrity/iint.c | 7 ++-
> security/integrity/ima/ima.h | 6 ++
> security/integrity/ima/ima_main.c | 63 ++++++++++++++-------
> security/integrity/integrity.h | 9 +++
> security/keys/key.c | 9 +--
> security/security.c | 53 +++--------------
> 11 files changed, 72 insertions(+), 186 deletions(-)
>
> diff --git a/fs/file_table.c b/fs/file_table.c
> index 964e24120684..7b9c756a42df 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>
>
> @@ -376,7 +375,6 @@ 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 efed0e1e93f5..a200021209c3 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>
> @@ -3636,8 +3635,6 @@ 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)) {
> @@ -3701,7 +3698,6 @@ static int vfs_tmpfile(struct mnt_idmap *idmap,
> spin_unlock(&inode->i_lock);
> }
> security_inode_post_create_tmpfile(idmap, dir, file, mode);
> - ima_post_create_tmpfile(idmap, dir, file, mode);
> return 0;
> }
>
> @@ -4049,9 +4045,6 @@ 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_stripped, 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 3450bb1c8a18..94bbd7ac8b68 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>
> @@ -868,12 +867,6 @@ __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 0c55c8e7f837..6825ac1d07a9 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 6e4d060ff378..58591b5cbdb4 100644
> --- a/include/linux/ima.h
> +++ b/include/linux/ima.h
> @@ -16,26 +16,7 @@ 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 file *file,
> - 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);
> -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);
> -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 +41,11 @@ 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 file *file,
> - 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 +96,6 @@ 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 a462df827de2..32f0f3c5c4dd 100644
> --- a/security/integrity/iint.c
> +++ b/security/integrity/iint.c
> @@ -167,20 +167,21 @@ 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 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 f8581032e62c..0e4f882fcdce 100644
> --- a/security/integrity/ima/ima_main.c
> +++ b/security/integrity/ima/ima_main.c
> @@ -188,7 +188,7 @@ 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;
> @@ -413,8 +413,8 @@ 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;
> @@ -452,8 +452,8 @@ 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;
> @@ -511,7 +511,7 @@ 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;
> @@ -673,9 +673,8 @@ 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 file *file,
> - umode_t mode)
> +static void ima_post_create_tmpfile(struct mnt_idmap *idmap, struct inode *dir,
> + struct file *file, umode_t mode)
> {
> struct integrity_iint_cache *iint;
> struct inode *inode = file_inode(file);
> @@ -710,9 +709,9 @@ 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;
> @@ -751,8 +750,8 @@ 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;
> @@ -801,8 +800,8 @@ 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;
> @@ -835,7 +834,7 @@ 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;
>
> @@ -889,9 +888,9 @@ 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) &&
> @@ -1120,4 +1119,28 @@ static int __init init_ima(void)
> return error;
> }
>
> +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_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 7167a6e99bdc..7adc7d6c4f9f 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
> @@ -191,6 +192,14 @@ 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 0f9c6faf3491..2acf9fa80735 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 e6783c2f0c65..8c5b8ffeef92 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -1098,12 +1098,7 @@ 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);
> }
>
> /**
> @@ -2793,13 +2788,8 @@ 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);
> }
>
> /**
> @@ -2828,12 +2818,7 @@ 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);
> }
>
> /**
> @@ -3163,12 +3148,7 @@ 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);
>
> @@ -3188,12 +3168,7 @@ 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);
>
> @@ -3208,12 +3183,7 @@ 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);
>
> @@ -3235,13 +3205,8 @@ 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);
>
> --
> 2.34.1
>
--
Chuck Lever