diff options
| -rw-r--r-- | Documentation/security/Smack.txt | 3 | ||||
| -rw-r--r-- | security/smack/smackfs.c | 75 |
2 files changed, 78 insertions, 0 deletions
diff --git a/Documentation/security/Smack.txt b/Documentation/security/Smack.txt index a416479b8a1c..e68536d85680 100644 --- a/Documentation/security/Smack.txt +++ b/Documentation/security/Smack.txt @@ -194,6 +194,9 @@ onlycap these capabilities are effective at for processes with any label. The value is set by writing the desired label to the file or cleared by writing "-" to the file. +revoke-subject + Writing a Smack label here sets the access to '-' for all access + rules with that subject label. You can add access rules in /etc/smack/accesses. They take the form: diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c index b1b768e4049a..99929a50093a 100644 --- a/security/smack/smackfs.c +++ b/security/smack/smackfs.c @@ -49,6 +49,7 @@ enum smk_inos { SMK_LOAD_SELF2 = 15, /* load task specific rules with long labels */ SMK_ACCESS2 = 16, /* make an access check with long labels */ SMK_CIPSO2 = 17, /* load long label -> CIPSO mapping */ + SMK_REVOKE_SUBJ = 18, /* set rules with subject label to '-' */ }; /* @@ -1992,6 +1993,77 @@ static const struct file_operations smk_access2_ops = { }; /** + * smk_write_revoke_subj - write() for /smack/revoke-subject + * @file: file pointer + * @buf: data from user space + * @count: bytes sent + * @ppos: where to start - must be 0 + */ +static ssize_t smk_write_revoke_subj(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + char *data = NULL; + const char *cp = NULL; + struct smack_known *skp; + struct smack_rule *sp; + struct list_head *rule_list; + struct mutex *rule_lock; + int rc = count; + + if (*ppos != 0) + return -EINVAL; + + if (!smack_privileged(CAP_MAC_ADMIN)) + return -EPERM; + + if (count == 0 || count > SMK_LONGLABEL) + return -EINVAL; + + data = kzalloc(count, GFP_KERNEL); + if (data == NULL) + return -ENOMEM; + + if (copy_from_user(data, buf, count) != 0) { + rc = -EFAULT; + goto free_out; + } + + cp = smk_parse_smack(data, count); + if (cp == NULL) { + rc = -EINVAL; + goto free_out; + } + + skp = smk_find_entry(cp); + if (skp == NULL) { + rc = -EINVAL; + goto free_out; + } + + rule_list = &skp->smk_rules; + rule_lock = &skp->smk_rules_lock; + + mutex_lock(rule_lock); + + list_for_each_entry_rcu(sp, rule_list, list) + sp->smk_access = 0; + + mutex_unlock(rule_lock); + +free_out: + kfree(data); + kfree(cp); + return rc; +} + +static const struct file_operations smk_revoke_subj_ops = { + .write = smk_write_revoke_subj, + .read = simple_transaction_read, + .release = simple_transaction_release, + .llseek = generic_file_llseek, +}; + +/** * smk_fill_super - fill the /smackfs superblock * @sb: the empty superblock * @data: unused @@ -2037,6 +2109,9 @@ static int smk_fill_super(struct super_block *sb, void *data, int silent) "access2", &smk_access2_ops, S_IRUGO|S_IWUGO}, [SMK_CIPSO2] = { "cipso2", &smk_cipso2_ops, S_IRUGO|S_IWUSR}, + [SMK_REVOKE_SUBJ] = { + "revoke-subject", &smk_revoke_subj_ops, + S_IRUGO|S_IWUSR}, /* last one */ {""} }; |