On Wed, 2011-04-27 at 14:34 +0200, Roberto Sassu wrote:
> The new parameters 'fowner_user', 'fowner_role' and 'fowner_type' are new
> LSM conditions that allow to measure inodes whose opened file descriptor
> has the label given as a value.
>
> Signed-off-by: Roberto Sassu <roberto.sassu@xxxxxxxxx>
Nice. I really like the 'fowner_' prefix. If you don't object, I'll
change the ima-appraisal keyword from 'owner' to 'fowner' as well.
Acked-by: Mimi Zohar <zohar@xxxxxxxxxxxxxxxxxx>
thanks,
Mimi
> ---
> Documentation/ABI/testing/ima_policy | 7 ++++-
> security/integrity/ima/ima.h | 4 +-
> security/integrity/ima/ima_api.c | 4 +-
> security/integrity/ima/ima_main.c | 4 +-
> security/integrity/ima/ima_policy.c | 45 +++++++++++++++++++++++++++++----
> 5 files changed, 51 insertions(+), 13 deletions(-)
>
> diff --git a/Documentation/ABI/testing/ima_policy b/Documentation/ABI/testing/ima_policy
> index 6cd6dae..ee49345 100644
> --- a/Documentation/ABI/testing/ima_policy
> +++ b/Documentation/ABI/testing/ima_policy
> @@ -18,7 +18,8 @@ Description:
> condition:= base | lsm
> base: [[func=] [mask=] [fsmagic=] [uid=]]
> lsm: [[subj_user=] [subj_role=] [subj_type=]
> - [obj_user=] [obj_role=] [obj_type=]]
> + [obj_user=] [obj_role=] [obj_type=]
> + [fowner_user=] [fowner_role=] [fowner_type=]]
>
> base: func:= [BPRM_CHECK][FILE_MMAP][FILE_CHECK]
> mask:= [MAY_READ] [MAY_WRITE] [MAY_APPEND] [MAY_EXEC]
> @@ -46,6 +47,10 @@ Description:
> all files mmapped executable in file_mmap, and all files
> open for read by root in do_filp_open.
>
> + LSM conditions starting with obj_ refer to security attributes
> + of inodes while those starting with fowner_ involve file
> + descriptors.
> +
> Examples of LSM specific definitions:
>
> SELinux:
> diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
> index 08408bd..3a05625 100644
> --- a/security/integrity/ima/ima.h
> +++ b/security/integrity/ima/ima.h
> @@ -110,7 +110,7 @@ struct ima_iint_cache {
> };
>
> /* LIM API function definitions */
> -int ima_must_measure(struct inode *inode, int mask, int function);
> +int ima_must_measure(struct file *file, int mask, int function);
> int ima_collect_measurement(struct ima_iint_cache *iint, struct file *file);
> void ima_store_measurement(struct ima_iint_cache *iint, struct file *file,
> const unsigned char *filename);
> @@ -128,7 +128,7 @@ struct ima_iint_cache *ima_iint_find(struct inode *inode);
> /* IMA policy related functions */
> enum ima_hooks { FILE_CHECK = 1, FILE_MMAP, BPRM_CHECK };
>
> -int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask);
> +int ima_match_policy(struct file *file, enum ima_hooks func, int mask);
> void ima_init_policy(void);
> void ima_update_policy(void);
> ssize_t ima_parse_add_rule(char *);
> diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
> index da36d2c..d815392 100644
> --- a/security/integrity/ima/ima_api.c
> +++ b/security/integrity/ima/ima_api.c
> @@ -108,11 +108,11 @@ err_out:
> * Return 0 to measure. For matching a DONT_MEASURE policy, no policy,
> * or other error, return an error code.
> */
> -int ima_must_measure(struct inode *inode, int mask, int function)
> +int ima_must_measure(struct file *file, int mask, int function)
> {
> int must_measure;
>
> - must_measure = ima_match_policy(inode, function, mask);
> + must_measure = ima_match_policy(file, function, mask);
> return must_measure ? 0 : -EACCES;
> }
>
> diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
> index 39d66dc..9eaca61 100644
> --- a/security/integrity/ima/ima_main.c
> +++ b/security/integrity/ima/ima_main.c
> @@ -65,7 +65,7 @@ static void ima_rdwr_violation_check(struct file *file)
> goto out;
> }
>
> - rc = ima_must_measure(inode, MAY_READ, FILE_CHECK);
> + rc = ima_must_measure(file, MAY_READ, FILE_CHECK);
> if (rc < 0)
> goto out;
>
> @@ -127,7 +127,7 @@ static int process_measurement(struct file *file, const unsigned char *filename,
> if (!ima_initialized || !S_ISREG(inode->i_mode))
> return 0;
>
> - rc = ima_must_measure(inode, mask, function);
> + rc = ima_must_measure(file, mask, function);
> if (rc != 0)
> return rc;
> retry:
> diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
> index d661afb..115c2e7 100644
> --- a/security/integrity/ima/ima_policy.c
> +++ b/security/integrity/ima/ima_policy.c
> @@ -27,9 +27,10 @@
>
> enum ima_action { UNKNOWN = -1, DONT_MEASURE = 0, MEASURE };
>
> -#define MAX_LSM_RULES 6
> +#define MAX_LSM_RULES 9
> enum lsm_rule_types { LSM_OBJ_USER, LSM_OBJ_ROLE, LSM_OBJ_TYPE,
> - LSM_SUBJ_USER, LSM_SUBJ_ROLE, LSM_SUBJ_TYPE
> + LSM_SUBJ_USER, LSM_SUBJ_ROLE, LSM_SUBJ_TYPE,
> + LSM_FOWNER_USER, LSM_FOWNER_ROLE, LSM_FOWNER_TYPE
> };
>
> struct ima_measure_rule_entry {
> @@ -96,9 +97,10 @@ __setup("ima_tcb", default_policy_setup);
> * Returns true on rule match, false on failure.
> */
> static bool ima_match_rules(struct ima_measure_rule_entry *rule,
> - struct inode *inode, enum ima_hooks func, int mask)
> + struct file *file, enum ima_hooks func, int mask)
> {
> struct task_struct *tsk = current;
> + struct inode *inode = file->f_dentry->d_inode;
> int i;
>
> if ((rule->flags & IMA_FUNC) && rule->func != func)
> @@ -112,7 +114,7 @@ static bool ima_match_rules(struct ima_measure_rule_entry *rule,
> return false;
> for (i = 0; i < MAX_LSM_RULES; i++) {
> int rc = 0;
> - u32 osid, sid;
> + u32 osid, sid, fsid;
>
> if (!rule->lsm[i].rule)
> continue;
> @@ -137,6 +139,15 @@ static bool ima_match_rules(struct ima_measure_rule_entry *rule,
> Audit_equal,
> rule->lsm[i].rule,
> NULL);
> + case LSM_FOWNER_USER:
> + case LSM_FOWNER_ROLE:
> + case LSM_FOWNER_TYPE:
> + security_file_getsecid(file, &fsid);
> + rc = security_filter_rule_match(fsid,
> + rule->lsm[i].type,
> + Audit_equal,
> + rule->lsm[i].rule,
> + NULL);
> default:
> break;
> }
> @@ -159,14 +170,14 @@ static bool ima_match_rules(struct ima_measure_rule_entry *rule,
> * as elements in the list are never deleted, nor does the list
> * change.)
> */
> -int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask)
> +int ima_match_policy(struct file *file, enum ima_hooks func, int mask)
> {
> struct ima_measure_rule_entry *entry;
>
> list_for_each_entry(entry, ima_measure, list) {
> bool rc;
>
> - rc = ima_match_rules(entry, inode, func, mask);
> + rc = ima_match_rules(entry, file, func, mask);
> if (rc)
> return entry->action;
> }
> @@ -222,6 +233,7 @@ enum {
> Opt_measure = 1, Opt_dont_measure,
> Opt_obj_user, Opt_obj_role, Opt_obj_type,
> Opt_subj_user, Opt_subj_role, Opt_subj_type,
> + Opt_fowner_user, Opt_fowner_role, Opt_fowner_type,
> Opt_func, Opt_mask, Opt_fsmagic, Opt_uid
> };
>
> @@ -234,6 +246,9 @@ static match_table_t policy_tokens = {
> {Opt_subj_user, "subj_user=%s"},
> {Opt_subj_role, "subj_role=%s"},
> {Opt_subj_type, "subj_type=%s"},
> + {Opt_fowner_user, "fowner_user=%s"},
> + {Opt_fowner_role, "fowner_role=%s"},
> + {Opt_fowner_type, "fowner_type=%s"},
> {Opt_func, "func=%s"},
> {Opt_mask, "mask=%s"},
> {Opt_fsmagic, "fsmagic=%s"},
> @@ -407,6 +422,24 @@ static int ima_parse_rule(char *rule, struct ima_measure_rule_entry *entry)
> LSM_SUBJ_TYPE,
> AUDIT_SUBJ_TYPE);
> break;
> + case Opt_fowner_user:
> + ima_log_string(ab, "fowner_user", args[0].from);
> + result = ima_lsm_rule_init(entry, args[0].from,
> + LSM_FOWNER_USER,
> + AUDIT_SUBJ_USER);
> + break;
> + case Opt_fowner_role:
> + ima_log_string(ab, "fowner_role", args[0].from);
> + result = ima_lsm_rule_init(entry, args[0].from,
> + LSM_FOWNER_ROLE,
> + AUDIT_SUBJ_ROLE);
> + break;
> + case Opt_fowner_type:
> + ima_log_string(ab, "fowner_type", args[0].from);
> + result = ima_lsm_rule_init(entry, args[0].from,
> + LSM_FOWNER_TYPE,
> + AUDIT_SUBJ_TYPE);
> + break;
> case Opt_err:
> ima_log_string(ab, "UNKNOWN", p);
> result = -EINVAL;
--
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