diff options
| -rw-r--r-- | Documentation/security/Smack.txt | 6 | ||||
| -rw-r--r-- | security/smack/smack.h | 25 | ||||
| -rw-r--r-- | security/smack/smack_access.c | 68 | ||||
| -rw-r--r-- | security/smack/smack_lsm.c | 96 | ||||
| -rw-r--r-- | security/smack/smackfs.c | 311 |
5 files changed, 317 insertions, 189 deletions
diff --git a/Documentation/security/Smack.txt b/Documentation/security/Smack.txt index abc82f85215b..de5e1aeca7fb 100644 --- a/Documentation/security/Smack.txt +++ b/Documentation/security/Smack.txt @@ -206,11 +206,11 @@ netlabel label. The format accepted on write is: "%d.%d.%d.%d label" or "%d.%d.%d.%d/%d label". onlycap - This contains the label processes must have for CAP_MAC_ADMIN + This contains labels processes must have for CAP_MAC_ADMIN and CAP_MAC_OVERRIDE to be effective. If this file is empty 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. + label. The values are set by writing the desired labels, separated + by spaces, to the file or cleared by writing "-" to the file. ptrace This is used to define the current ptrace policy 0 - default: this is the policy that relies on Smack access rules. diff --git a/security/smack/smack.h b/security/smack/smack.h index b8c1a869d85e..244e035e5a99 100644 --- a/security/smack/smack.h +++ b/security/smack/smack.h @@ -138,6 +138,11 @@ struct smk_port_label { struct smack_known *smk_out; /* outgoing label */ }; +struct smack_onlycap { + struct list_head list; + struct smack_known *smk_label; +}; + /* * Mount options */ @@ -249,6 +254,7 @@ int smk_netlbl_mls(int, char *, struct netlbl_lsm_secattr *, int); struct smack_known *smk_import_entry(const char *, int); void smk_insert_entry(struct smack_known *skp); struct smack_known *smk_find_entry(const char *); +int smack_privileged(int cap); /* * Shared data. @@ -257,7 +263,6 @@ extern int smack_enabled; extern int smack_cipso_direct; extern int smack_cipso_mapped; extern struct smack_known *smack_net_ambient; -extern struct smack_known *smack_onlycap; extern struct smack_known *smack_syslog_label; #ifdef CONFIG_SECURITY_SMACK_BRINGUP extern struct smack_known *smack_unconfined; @@ -276,6 +281,9 @@ extern struct mutex smack_known_lock; extern struct list_head smack_known_list; extern struct list_head smk_netlbladdr_list; +extern struct mutex smack_onlycap_lock; +extern struct list_head smack_onlycap_list; + #define SMACK_HASH_SLOTS 16 extern struct hlist_head smack_known_hash[SMACK_HASH_SLOTS]; @@ -332,21 +340,6 @@ static inline struct smack_known *smk_of_current(void) } /* - * Is the task privileged and allowed to be privileged - * by the onlycap rule. - */ -static inline int smack_privileged(int cap) -{ - struct smack_known *skp = smk_of_current(); - - if (!capable(cap)) - return 0; - if (smack_onlycap == NULL || smack_onlycap == skp) - return 1; - return 0; -} - -/* * logging functions */ #define SMACK_AUDIT_DENIED 0x1 diff --git a/security/smack/smack_access.c b/security/smack/smack_access.c index 0f410fc56e33..00f6b38bffbd 100644 --- a/security/smack/smack_access.c +++ b/security/smack/smack_access.c @@ -425,7 +425,7 @@ void smk_insert_entry(struct smack_known *skp) * @string: a text string that might be a Smack label * * Returns a pointer to the entry in the label list that - * matches the passed string. + * matches the passed string or NULL if not found. */ struct smack_known *smk_find_entry(const char *string) { @@ -448,7 +448,7 @@ struct smack_known *smk_find_entry(const char *string) * @string: a text string that might contain a Smack label * @len: the maximum size, or zero if it is NULL terminated. * - * Returns a pointer to the clean label, or NULL + * Returns a pointer to the clean label or an error code. */ char *smk_parse_smack(const char *string, int len) { @@ -464,7 +464,7 @@ char *smk_parse_smack(const char *string, int len) * including /smack/cipso and /smack/cipso2 */ if (string[0] == '-') - return NULL; + return ERR_PTR(-EINVAL); for (i = 0; i < len; i++) if (string[i] > '~' || string[i] <= ' ' || string[i] == '/' || @@ -472,11 +472,13 @@ char *smk_parse_smack(const char *string, int len) break; if (i == 0 || i >= SMK_LONGLABEL) - return NULL; + return ERR_PTR(-EINVAL); smack = kzalloc(i + 1, GFP_KERNEL); - if (smack != NULL) - strncpy(smack, string, i); + if (smack == NULL) + return ERR_PTR(-ENOMEM); + + strncpy(smack, string, i); return smack; } @@ -523,7 +525,8 @@ int smk_netlbl_mls(int level, char *catset, struct netlbl_lsm_secattr *sap, * @len: the maximum size, or zero if it is NULL terminated. * * Returns a pointer to the entry in the label list that - * matches the passed string, adding it if necessary. + * matches the passed string, adding it if necessary, + * or an error code. */ struct smack_known *smk_import_entry(const char *string, int len) { @@ -533,8 +536,8 @@ struct smack_known *smk_import_entry(const char *string, int len) int rc; smack = smk_parse_smack(string, len); - if (smack == NULL) - return NULL; + if (IS_ERR(smack)) + return ERR_CAST(smack); mutex_lock(&smack_known_lock); @@ -543,8 +546,10 @@ struct smack_known *smk_import_entry(const char *string, int len) goto freeout; skp = kzalloc(sizeof(*skp), GFP_KERNEL); - if (skp == NULL) + if (skp == NULL) { + skp = ERR_PTR(-ENOMEM); goto freeout; + } skp->smk_known = smack; skp->smk_secid = smack_next_secid++; @@ -577,7 +582,7 @@ struct smack_known *smk_import_entry(const char *string, int len) * smk_netlbl_mls failed. */ kfree(skp); - skp = NULL; + skp = ERR_PTR(rc); freeout: kfree(smack); unlockout: @@ -612,3 +617,44 @@ struct smack_known *smack_from_secid(const u32 secid) rcu_read_unlock(); return &smack_known_invalid; } + +/* + * Unless a process is running with one of these labels + * even having CAP_MAC_OVERRIDE isn't enough to grant + * privilege to violate MAC policy. If no labels are + * designated (the empty list case) capabilities apply to + * everyone. + */ +LIST_HEAD(smack_onlycap_list); +DEFINE_MUTEX(smack_onlycap_lock); + +/* + * Is the task privileged and allowed to be privileged + * by the onlycap rule. + * + * Returns 1 if the task is allowed to be privileged, 0 if it's not. + */ +int smack_privileged(int cap) +{ + struct smack_known *skp = smk_of_current(); + struct smack_onlycap *sop; + + if (!capable(cap)) + return 0; + + rcu_read_lock(); + if (list_empty(&smack_onlycap_list)) { + rcu_read_unlock(); + return 1; + } + + list_for_each_entry_rcu(sop, &smack_onlycap_list, list) { + if (sop->smk_label == skp) { + rcu_read_unlock(); + return 1; + } + } + rcu_read_unlock(); + + return 0; +} diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 5eae42c8d0d5..a143328f75eb 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -245,8 +245,8 @@ static int smk_bu_credfile(const struct cred *cred, struct file *file, * @ip: a pointer to the inode * @dp: a pointer to the dentry * - * Returns a pointer to the master list entry for the Smack label - * or NULL if there was no label to fetch. + * Returns a pointer to the master list entry for the Smack label, + * NULL if there was no label to fetch, or an error code. */ static struct smack_known *smk_fetch(const char *name, struct inode *ip, struct dentry *dp) @@ -256,14 +256,18 @@ static struct smack_known *smk_fetch(const char *name, struct inode *ip, struct smack_known *skp = NULL; if (ip->i_op->getxattr == NULL) - return NULL; + return ERR_PTR(-EOPNOTSUPP); buffer = kzalloc(SMK_LONGLABEL, GFP_KERNEL); if (buffer == NULL) - return NULL; + return ERR_PTR(-ENOMEM); rc = ip->i_op->getxattr(dp, name, buffer, SMK_LONGLABEL); - if (rc > 0) + if (rc < 0) + skp = ERR_PTR(rc); + else if (rc == 0) + skp = NULL; + else skp = smk_import_entry(buffer, rc); kfree(buffer); @@ -605,40 +609,44 @@ static int smack_sb_kern_mount(struct super_block *sb, int flags, void *data) if (strncmp(op, SMK_FSHAT, strlen(SMK_FSHAT)) == 0) { op += strlen(SMK_FSHAT); skp = smk_import_entry(op, 0); - if (skp != NULL) { - sp->smk_hat = skp; - specified = 1; - } + if (IS_ERR(skp)) + return PTR_ERR(skp); + sp->smk_hat = skp; + specified = 1; + } else if (strncmp(op, SMK_FSFLOOR, strlen(SMK_FSFLOOR)) == 0) { op += strlen(SMK_FSFLOOR); skp = smk_import_entry(op, 0); - if (skp != NULL) { - sp->smk_floor = skp; - specified = 1; - } + if (IS_ERR(skp)) + return PTR_ERR(skp); + sp->smk_floor = skp; + specified = 1; + } else if (strncmp(op, SMK_FSDEFAULT, strlen(SMK_FSDEFAULT)) == 0) { op += strlen(SMK_FSDEFAULT); skp = smk_import_entry(op, 0); - if (skp != NULL) { - sp->smk_default = skp; - specified = 1; - } + if (IS_ERR(skp)) + return PTR_ERR(skp); + sp->smk_default = skp; + specified = 1; + } else if (strncmp(op, SMK_FSROOT, strlen(SMK_FSROOT)) == 0) { op += strlen(SMK_FSROOT); skp = smk_import_entry(op, 0); - if (skp != NULL) { - sp->smk_root = skp; - specified = 1; - } + if (IS_ERR(skp)) + return PTR_ERR(skp); + sp->smk_root = skp; + specified = 1; + } else if (strncmp(op, SMK_FSTRANS, strlen(SMK_FSTRANS)) == 0) { op += strlen(SMK_FSTRANS); skp = smk_import_entry(op, 0); - if (skp != NULL) { - sp->smk_root = skp; - transmute = 1; - specified = 1; - } + if (IS_ERR(skp)) + return PTR_ERR(skp); + sp->smk_root = skp; + transmute = 1; + specified = 1; } } @@ -1118,7 +1126,9 @@ static int smack_inode_setxattr(struct dentry *dentry, const char *name, if (rc == 0 && check_import) { skp = size ? smk_import_entry(value, size) : NULL; - if (skp == NULL || (check_star && + if (IS_ERR(skp)) + rc = PTR_ERR(skp); + else if (skp == NULL || (check_star && (skp == &smack_known_star || skp == &smack_known_web))) rc = -EINVAL; } @@ -1158,19 +1168,19 @@ static void smack_inode_post_setxattr(struct dentry *dentry, const char *name, if (strcmp(name, XATTR_NAME_SMACK) == 0) { skp = smk_import_entry(value, size); - if (skp != NULL) + if (!IS_ERR(skp)) isp->smk_inode = skp; else isp->smk_inode = &smack_known_invalid; } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0) { skp = smk_import_entry(value, size); - if (skp != NULL) + if (!IS_ERR(skp)) isp->smk_task = skp; else isp->smk_task = &smack_known_invalid; } else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0) { skp = smk_import_entry(value, size); - if (skp != NULL) + if (!IS_ERR(skp)) isp->smk_mmap = skp; else isp->smk_mmap = &smack_known_invalid; @@ -1658,6 +1668,9 @@ static int smack_file_receive(struct file *file) struct smk_audit_info ad; struct inode *inode = file_inode(file); + if (unlikely(IS_PRIVATE(inode))) + return 0; + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); smk_ad_setfield_u_fs_path(&ad, file->f_path); /* @@ -2400,8 +2413,8 @@ static int smack_inode_setsecurity(struct inode *inode, const char *name, return -EINVAL; skp = smk_import_entry(value, size); - if (skp == NULL) - return -EINVAL; + if (IS_ERR(skp)) + return PTR_ERR(skp); if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) { nsp->smk_inode = skp; @@ -3174,7 +3187,7 @@ static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode) */ dp = dget(opt_dentry); skp = smk_fetch(XATTR_NAME_SMACK, inode, dp); - if (skp != NULL) + if (!IS_ERR_OR_NULL(skp)) final = skp; /* @@ -3211,11 +3224,14 @@ static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode) * Don't let the exec or mmap label be "*" or "@". */ skp = smk_fetch(XATTR_NAME_SMACKEXEC, inode, dp); - if (skp == &smack_known_star || skp == &smack_known_web) + if (IS_ERR(skp) || skp == &smack_known_star || + skp == &smack_known_web) skp = NULL; isp->smk_task = skp; + skp = smk_fetch(XATTR_NAME_SMACKMMAP, inode, dp); - if (skp == &smack_known_star || skp == &smack_known_web) + if (IS_ERR(skp) || skp == &smack_known_star || + skp == &smack_known_web) skp = NULL; isp->smk_mmap = skp; @@ -3299,8 +3315,8 @@ static int smack_setprocattr(struct task_struct *p, char *name, return -EINVAL; skp = smk_import_entry(value, size); - if (skp == NULL) - return -EINVAL; + if (IS_ERR(skp)) + return PTR_ERR(skp); /* * No process is ever allowed the web ("@") label. @@ -4075,8 +4091,10 @@ static int smack_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule) return -EINVAL; skp = smk_import_entry(rulestr, 0); - if (skp) - *rule = skp->smk_known; + if (IS_ERR(skp)) + return PTR_ERR(skp); + + *rule = skp->smk_known; return 0; } diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c index 4aa12c8d3c63..f1c22a891b1a 100644 --- a/security/smack/smackfs.c +++ b/security/smack/smackfs.c @@ -87,16 +87,6 @@ int smack_cipso_direct = SMACK_CIPSO_DIRECT_DEFAULT; */ int smack_cipso_mapped = SMACK_CIPSO_MAPPED_DEFAULT; -/* - * Unless a process is running with this label even - * having CAP_MAC_OVERRIDE isn't enough to grant - * privilege to violate MAC policy. If no label is - * designated (the NULL case) capabilities apply to - * everyone. It is expected that the hat (^) label - * will be used if any label is used. - */ -struct smack_known *smack_onlycap; - #ifdef CONFIG_SECURITY_SMACK_BRINGUP /* * Allow one label to be unconfined. This is for @@ -338,8 +328,7 @@ static int smk_perm_from_str(const char *string) * @import: if non-zero, import labels * @len: label length limit * - * Returns 0 on success, -EINVAL on failure and -ENOENT when either subject - * or object is missing. + * Returns 0 on success, appropriate error code on failure. */ static int smk_fill_rule(const char *subject, const char *object, const char *access1, const char *access2, @@ -351,16 +340,16 @@ static int smk_fill_rule(const char *subject, const char *object, if (import) { rule->smk_subject = smk_import_entry(subject, len); - if (rule->smk_subject == NULL) - return -EINVAL; + if (IS_ERR(rule->smk_subject)) + return PTR_ERR(rule->smk_subject); rule->smk_object = smk_import_entry(object, len); - if (rule->smk_object == NULL) - return -EINVAL; + if (IS_ERR(rule->smk_object)) + return PTR_ERR(rule->smk_object); } else { cp = smk_parse_smack(subject, len); - if (cp == NULL) - return -EINVAL; + if (IS_ERR(cp)) + return PTR_ERR(cp); skp = smk_find_entry(cp); kfree(cp); if (skp == NULL) @@ -368,8 +357,8 @@ static int smk_fill_rule(const char *subject, const char *object, rule->smk_subject = skp; cp = smk_parse_smack(object, len); - if (cp == NULL) - return -EINVAL; + if (IS_ERR(cp)) + return PTR_ERR(cp); skp = smk_find_entry(cp); kfree(cp); if (skp == NULL) @@ -412,7 +401,7 @@ static int smk_parse_rule(const char *data, struct smack_parsed_rule *rule, * @import: if non-zero, import labels * @tokens: numer of substrings expected in data * - * Returns number of processed bytes on success, -1 on failure. + * Returns number of processed bytes on success, -ERRNO on failure. */ static ssize_t smk_parse_long_rule(char *data, struct smack_parsed_rule *rule, int import, int tokens) @@ -431,7 +420,7 @@ static ssize_t smk_parse_long_rule(char *data, struct smack_parsed_rule *rule, if (data[cnt] == '\0') /* Unexpected end of data */ - return -1; + return -EINVAL; tok[i] = data + cnt; @@ -529,14 +518,14 @@ static ssize_t smk_write_rules_list(struct file *file, const char __user *buf, while (cnt < count) { if (format == SMK_FIXED24_FMT) { rc = smk_parse_rule(data, &rule, 1); - if (rc != 0) { - rc = -EINVAL; + if (rc < 0) goto out; - } cnt = count; } else { rc = smk_parse_long_rule(data + cnt, &rule, 1, tokens); - if (rc <= 0) { + if (rc < 0) + goto out; + if (rc == 0) { rc = -EINVAL; goto out; } @@ -567,23 +556,17 @@ static void *smk_seq_start(struct seq_file *s, loff_t *pos, struct list_head *head) { struct list_head *list; + int i = *pos; + + rcu_read_lock(); + for (list = rcu_dereference(list_next_rcu(head)); + list != head; + list = rcu_dereference(list_next_rcu(list))) { + if (i-- == 0) + return list; + } - /* - * This is 0 the first time through. - */ - if (s->index == 0) - s->private = head; - - if (s->private == NULL) - return NULL; - - list = s->private; - if (list_empty(list)) - return NULL; - - if (s->index == 0) - return list->next; - return list; + return NULL; } static void *smk_seq_next(struct seq_file *s, void *v, loff_t *pos, @@ -591,17 +574,15 @@ static void *smk_seq_next(struct seq_file *s, void *v, loff_t *pos, { struct list_head *list = v; - if (list_is_last(list, head)) { - s->private = NULL; - return NULL; - } - s->private = list->next; - return list->next; + ++*pos; + list = rcu_dereference(list_next_rcu(list)); + + return (list == head) ? NULL : list; } static void smk_seq_stop(struct seq_file *s, void *v) { - /* No-op */ + rcu_read_unlock(); } static void smk_rule_show(struct seq_file *s, struct smack_rule *srp, int max) @@ -661,7 +642,7 @@ static int load_seq_show(struct seq_file *s, void *v) { struct list_head *list = v; struct smack_master_list *smlp = - list_entry(list, struct smack_master_list, list); + list_entry_rcu(list, struct smack_master_list, list); smk_rule_show(s, smlp->smk_rule, SMK_LABELLEN); @@ -809,7 +790,7 @@ static int cipso_seq_show(struct seq_file *s, void *v) { struct list_head *list = v; struct smack_known *skp = - list_entry(list, struct smack_known, list); + list_entry_rcu(list, struct smack_known, list); struct netlbl_lsm_catmap *cmp = skp->smk_netlabel.attr.mls.cat; char sep = '/'; int i; @@ -915,8 +896,10 @@ static ssize_t smk_set_cipso(struct file *file, const char __user *buf, mutex_lock(&smack_cipso_lock); skp = smk_import_entry(rule, 0); - if (skp == NULL) + if (IS_ERR(skp)) { + rc = PTR_ERR(skp); goto out; + } if (format == SMK_FIXED24_FMT) rule += SMK_LABELLEN; @@ -998,7 +981,7 @@ static int cipso2_seq_show(struct seq_file *s, void *v) { struct list_head *list = v; struct smack_known *skp = - list_entry(list, struct smack_known, list); + list_entry_rcu(list, struct smack_known, list); struct netlbl_lsm_catmap *cmp = skp->smk_netlabel.attr.mls.cat; char sep = '/'; int i; @@ -1082,7 +1065,7 @@ static int netlbladdr_seq_show(struct seq_file *s, void *v) { struct list_head *list = v; struct smk_netlbladdr *skp = - list_entry(list, struct smk_netlbladdr, list); + list_entry_rcu(list, struct smk_netlbladdr, list); unsigned char *hp = (char *) &skp->smk_host.sin_addr.s_addr; int maskn; u32 temp_mask = be32_to_cpu(skp->smk_mask.s_addr); @@ -1237,8 +1220,8 @@ static ssize_t smk_write_netlbladdr(struct file *file, const char __user *buf, */ if (smack[0] != '-') { skp = smk_import_entry(smack, 0); - if (skp == NULL) { - rc = -EINVAL; + if (IS_ERR(skp)) { + rc = PTR_ERR(skp); goto free_out; } } else { @@ -1619,8 +1602,8 @@ static ssize_t smk_write_ambient(struct file *file, const char __user *buf, } skp = smk_import_entry(data, count); - if (skp == NULL) { - rc = -EINVAL; + if (IS_ERR(skp)) { + rc = PTR_ERR(skp); goto out; } @@ -1643,34 +1626,79 @@ static const struct file_operations smk_ambient_ops = { .llseek = default_llseek, }; -/** - * smk_read_onlycap - read() for smackfs/onlycap - * @filp: file pointer, not actually used - * @buf: where to put the result - * @cn: maximum to send along - * @ppos: where to start - * - * Returns number of bytes read or error code, as appropriate +/* + * Seq_file operations for /smack/onlycap */ -static ssize_t smk_read_onlycap(struct file *filp, char __user *buf, - size_t cn, loff_t *ppos) +static void *onlycap_seq_start(struct seq_file *s, loff_t *pos) { - char *smack = ""; - ssize_t rc = -EINVAL; - int asize; + return smk_seq_start(s, pos, &smack_onlycap_list); +} - if (*ppos != 0) - return 0; +static void *onlycap_seq_next(struct seq_file *s, void *v, loff_t *pos) +{ + return smk_seq_next(s, v, pos, &smack_onlycap_list); +} - if (smack_onlycap != NULL) - smack = smack_onlycap->smk_known; +static int onlycap_seq_show(struct seq_file *s, void *v) +{ + struct list_head *list = v; + struct smack_onlycap *sop = + list_entry_rcu(list, struct smack_onlycap, list); - asize = strlen(smack) + 1; + seq_puts(s, sop->smk_label->smk_known); + seq_putc(s, ' '); - if (cn >= asize) - rc = simple_read_from_buffer(buf, cn, ppos, smack, asize); + return 0; +} - return rc; +static const struct seq_operations onlycap_seq_ops = { + .start = onlycap_seq_start, + .next = onlycap_seq_next, + .show = onlycap_seq_show, + .stop = smk_seq_stop, +}; + +static int smk_open_onlycap(struct inode *inode, struct file *file) +{ + return seq_open(file, &onlycap_seq_ops); +} + +/** + * smk_list_swap_rcu - swap public list with a private one in RCU-safe way + * The caller must hold appropriate mutex to prevent concurrent modifications + * to the public list. + * Private list is assumed to be not accessible to other threads yet. + * + * @public: public list + * @private: private list + */ +static void smk_list_swap_rcu(struct list_head *public, + struct list_head *private) +{ + struct list_head *first, *last; + + if (list_empty(public)) { + list_splice_init_rcu(private, public, synchronize_rcu); + } else { + /* Remember public list before replacing it */ + first = public->next; + last = public->prev; + + /* Publish private list in place of public in RCU-safe way */ + private->prev->next = public; + private->next->prev = public; + rcu_assign_pointer(public->next, private->next); + public->prev = private->prev; + + synchronize_rcu(); + + /* When all readers are done with the old public list, + * attach it in place of private */ + private->next = first; + private->prev = last; + first->prev = private; + last->next = private; + } } /** @@ -1686,47 +1714,79 @@ static ssize_t smk_write_onlycap(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { char *data; - struct smack_known *skp = smk_of_task(current->cred->security); + char *data_parse; + char *tok; + struct smack_known *skp; + struct smack_onlycap *sop; + struct smack_onlycap *sop2; + LIST_HEAD(list_tmp); int rc = count; if (!smack_privileged(CAP_MAC_ADMIN)) return -EPERM; - /* - * This can be done using smk_access() but is done - * explicitly for clarity. The smk_access() implementation - * would use smk_access(smack_onlycap, MAY_WRITE) - */ - if (smack_onlycap != NULL && smack_onlycap != skp) - return -EPERM; - data = kzalloc(count + 1, GFP_KERNEL); if (data == NULL) return -ENOMEM; + if (copy_from_user(data, buf, count) != 0) { + kfree(data); + return -EFAULT; + } + + data_parse = data; + while ((tok = strsep(&data_parse, " ")) != NULL) { + if (!*tok) + continue; + + skp = smk_import_entry(tok, 0); + if (IS_ERR(skp)) { + rc = PTR_ERR(skp); + break; + } + + sop = kzalloc(sizeof(*sop), GFP_KERNEL); + if (sop == NULL) { + rc = -ENOMEM; + break; + } + + sop->smk_label = skp; + list_add_rcu(&sop->list, &list_tmp); + } + kfree(data); + /* - * Should the null string be passed in unset the onlycap value. - * This seems like something to be careful with as usually - * smk_import only expects to return NULL for errors. It - * is usually the case that a nullstring or "\n" would be - * bad to pass to smk_import but in fact this is useful here. + * Clear the smack_onlycap on invalid label errors. This means + * that we can pass a null string to unset the onlycap value. * - * smk_import will also reject a label beginning with '-', + * Importing will also reject a label beginning with '-', * so "-usecapabilities" will also work. + * + * But do so only on invalid label, not on system errors. + * The invalid label must be first to count as clearing attempt. */ - if (copy_from_user(data, buf, count) != 0) - rc = -EFAULT; - else - smack_onlycap = smk_import_entry(data, count); + if (rc == -EINVAL && list_empty(&list_tmp)) + rc = count; + + if (rc >= 0) { + mutex_lock(&smack_onlycap_lock); + smk_list_swap_rcu(&smack_onlycap_list, &list_tmp); + mutex_unlock(&smack_onlycap_lock); + } + + list_for_each_entry_safe(sop, sop2, &list_tmp, list) + kfree(sop); - kfree(data); return rc; } static const struct file_operations smk_onlycap_ops = { - .read = smk_read_onlycap, + .open = smk_open_onlycap, + .read = seq_read, .write = smk_write_onlycap, - .llseek = default_llseek, + .llseek = seq_lseek, + .release = seq_release, }; #ifdef CONFIG_SECURITY_SMACK_BRINGUP @@ -1773,6 +1833,7 @@ static ssize_t smk_write_unconfined(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { char *data; + struct smack_known *skp; int rc = count; if (!smack_privileged(CAP_MAC_ADMIN)) @@ -1782,21 +1843,31 @@ static ssize_t smk_write_unconfined(struct file *file, const char __user *buf, if (data == NULL) return -ENOMEM; + if (copy_from_user(data, buf, count) != 0) { + rc = -EFAULT; + goto freeout; + } + /* - * Should the null string be passed in unset the unconfined value. - * This seems like something to be careful with as usually - * smk_import only expects to return NULL for errors. It - * is usually the case that a nullstring or "\n" would be - * bad to pass to smk_import but in fact this is useful here. + * Clear the smack_unconfined on invalid label errors. This means + * that we can pass a null string to unset the unconfined value. * - * smk_import will also reject a label beginning with '-', + * Importing will also reject a label beginning with '-', * so "-confine" will also work. + * + * But do so only on invalid label, not on system errors. */ - if (copy_from_user(data, buf, count) != 0) - rc = -EFAULT; - else - smack_unconfined = smk_import_entry(data, count); + skp = smk_import_entry(data, count); + if (PTR_ERR(skp) == -EINVAL) + skp = NULL; + else if (IS_ERR(skp)) { + rc = PTR_ERR(skp); + goto freeout; + } + + smack_unconfined = skp; +freeout: kfree(data); return rc; } @@ -1895,7 +1966,7 @@ static int load_self_seq_show(struct seq_file *s, void *v) { struct list_head *list = v; struct smack_rule *srp = - list_entry(list, struct smack_rule, list); + list_entry_rcu(list, struct smack_rule, list); smk_rule_show(s, srp, SMK_LABELLEN); @@ -1980,7 +2051,7 @@ static ssize_t smk_user_access(struct file *file, const char __user *buf, res = smk_access(rule.smk_subject, rule.smk_object, rule.smk_access1, NULL); else if (res != -ENOENT) - return -EINVAL; + return res; /* * smk_access() can return a value > 0 in the "bringup" case. @@ -2024,7 +2095,7 @@ static int load2_seq_show(struct seq_file *s, void *v) { struct list_head *list = v; struct smack_master_list *smlp = - list_entry(list, struct smack_master_list, list); + list_entry_rcu(list, struct smack_master_list, list); smk_rule_show(s, smlp->smk_rule, SMK_LONGLABEL); @@ -2101,7 +2172,7 @@ static int load_self2_seq_show(struct seq_file *s, void *v) { struct list_head *list = v; struct smack_rule *srp = - list_entry(list, struct smack_rule, list); + list_entry_rcu(list, struct smack_rule, list); smk_rule_show(s, srp, SMK_LONGLABEL); @@ -2209,8 +2280,8 @@ static ssize_t smk_write_revoke_subj(struct file *file, const char __user *buf, } cp = smk_parse_smack(data, count); - if (cp == NULL) { - rc = -EINVAL; + if (IS_ERR(cp)) { + rc = PTR_ERR(cp); goto free_out; } @@ -2341,10 +2412,10 @@ static ssize_t smk_write_syslog(struct file *file, const char __user *buf, rc = -EFAULT; else { skp = smk_import_entry(data, count); - if (skp == NULL) - rc = -EINVAL; + if (IS_ERR(skp)) + rc = PTR_ERR(skp); else - smack_syslog_label = smk_import_entry(data, count); + smack_syslog_label = skp; } kfree(data); |