lkml.org 
[lkml]   [2011]   [Apr]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[RFC][PATCH 7/7] ima: added new LSM conditions in the policy
    Date
    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@polito.it>
    ---
    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;
    --
    1.7.4.4
    [unhandled content-type:application/x-pkcs7-signature]
    \
     
     \ /
      Last update: 2011-04-27 14:39    [W:0.034 / U:91.884 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site