diff options
Diffstat (limited to 'security/smack')
-rw-r--r-- | security/smack/smack.h | 24 | ||||
-rw-r--r-- | security/smack/smack_access.c | 134 | ||||
-rw-r--r-- | security/smack/smack_lsm.c | 266 | ||||
-rw-r--r-- | security/smack/smackfs.c | 386 |
4 files changed, 506 insertions, 304 deletions
diff --git a/security/smack/smack.h b/security/smack/smack.h index 2b6c6a51612..2ad00657b80 100644 --- a/security/smack/smack.h +++ b/security/smack/smack.h @@ -41,9 +41,9 @@ struct superblock_smack { }; struct socket_smack { - char *smk_out; /* outbound label */ - char *smk_in; /* inbound label */ - char smk_packet[SMK_LABELLEN]; /* TCP peer label */ + char *smk_out; /* outbound label */ + char *smk_in; /* inbound label */ + char *smk_packet; /* TCP peer label */ }; /* @@ -116,13 +116,19 @@ struct smk_netlbladdr { * If there is a cipso value associated with the label it * gets stored here, too. This will most likely be rare as * the cipso direct mapping in used internally. + * + * Keep the access rules for this subject label here so that + * the entire set of rules does not need to be examined every + * time. */ struct smack_known { struct list_head list; char smk_known[SMK_LABELLEN]; u32 smk_secid; struct smack_cipso *smk_cipso; - spinlock_t smk_cipsolock; /* for changing cipso map */ + spinlock_t smk_cipsolock; /* for changing cipso map */ + struct list_head smk_rules; /* access rules */ + struct mutex smk_rules_lock; /* lock for the rules */ }; /* @@ -150,7 +156,6 @@ struct smack_known { /* * smackfs magic number - * smackfs macic number */ #define SMACK_MAGIC 0x43415d53 /* "SMAC" */ @@ -176,9 +181,9 @@ struct smack_known { #define MAY_NOT 0 /* - * Number of access types used by Smack (rwxa) + * Number of access types used by Smack (rwxat) */ -#define SMK_NUM_ACCESS_TYPE 4 +#define SMK_NUM_ACCESS_TYPE 5 /* * Smack audit data; is empty if CONFIG_AUDIT not set @@ -201,10 +206,12 @@ int smk_access_entry(char *, char *, struct list_head *); int smk_access(char *, char *, int, struct smk_audit_info *); int smk_curacc(char *, u32, struct smk_audit_info *); int smack_to_cipso(const char *, struct smack_cipso *); -void smack_from_cipso(u32, char *, char *); +char *smack_from_cipso(u32, char *); char *smack_from_secid(const u32); +void smk_parse_smack(const char *string, int len, char *smack); char *smk_import(const char *, int); struct smack_known *smk_import_entry(const char *, int); +struct smack_known *smk_find_entry(const char *); u32 smack_to_secid(const char *); /* @@ -223,7 +230,6 @@ extern struct smack_known smack_known_star; extern struct smack_known smack_known_web; extern struct list_head smack_known_list; -extern struct list_head smack_rule_list; extern struct list_head smk_netlbladdr_list; extern struct security_operations smack_ops; diff --git a/security/smack/smack_access.c b/security/smack/smack_access.c index 9637e107f7e..cc7cb6edba0 100644 --- a/security/smack/smack_access.c +++ b/security/smack/smack_access.c @@ -77,14 +77,19 @@ int log_policy = SMACK_AUDIT_DENIED; * entry is found returns -ENOENT. * * NOTE: - * Even though Smack labels are usually shared on smack_list - * labels that come in off the network can't be imported - * and added to the list for locking reasons. * - * Therefore, it is necessary to check the contents of the labels, - * not just the pointer values. Of course, in most cases the labels - * will be on the list, so checking the pointers may be a worthwhile - * optimization. + * Earlier versions of this function allowed for labels that + * were not on the label list. This was done to allow for + * labels to come over the network that had never been seen + * before on this host. Unless the receiving socket has the + * star label this will always result in a failure check. The + * star labeled socket case is now handled in the networking + * hooks so there is no case where the label is not on the + * label list. Checking to see if the address of two labels + * is the same is now a reliable test. + * + * Do the object check first because that is more + * likely to differ. */ int smk_access_entry(char *subject_label, char *object_label, struct list_head *rule_list) @@ -93,13 +98,10 @@ int smk_access_entry(char *subject_label, char *object_label, struct smack_rule *srp; list_for_each_entry_rcu(srp, rule_list, list) { - if (srp->smk_subject == subject_label || - strcmp(srp->smk_subject, subject_label) == 0) { - if (srp->smk_object == object_label || - strcmp(srp->smk_object, object_label) == 0) { - may = srp->smk_access; - break; - } + if (srp->smk_object == object_label && + srp->smk_subject == subject_label) { + may = srp->smk_access; + break; } } @@ -117,18 +119,12 @@ int smk_access_entry(char *subject_label, char *object_label, * access rule list and returns 0 if the access is permitted, * non zero otherwise. * - * Even though Smack labels are usually shared on smack_list - * labels that come in off the network can't be imported - * and added to the list for locking reasons. - * - * Therefore, it is necessary to check the contents of the labels, - * not just the pointer values. Of course, in most cases the labels - * will be on the list, so checking the pointers may be a worthwhile - * optimization. + * Smack labels are shared on smack_list */ int smk_access(char *subject_label, char *object_label, int request, struct smk_audit_info *a) { + struct smack_known *skp; int may = MAY_NOT; int rc = 0; @@ -137,8 +133,7 @@ int smk_access(char *subject_label, char *object_label, int request, * * A star subject can't access any object. */ - if (subject_label == smack_known_star.smk_known || - strcmp(subject_label, smack_known_star.smk_known) == 0) { + if (subject_label == smack_known_star.smk_known) { rc = -EACCES; goto out_audit; } @@ -148,33 +143,27 @@ int smk_access(char *subject_label, char *object_label, int request, * An internet subject can access any object. */ if (object_label == smack_known_web.smk_known || - subject_label == smack_known_web.smk_known || - strcmp(object_label, smack_known_web.smk_known) == 0 || - strcmp(subject_label, smack_known_web.smk_known) == 0) + subject_label == smack_known_web.smk_known) goto out_audit; /* * A star object can be accessed by any subject. */ - if (object_label == smack_known_star.smk_known || - strcmp(object_label, smack_known_star.smk_known) == 0) + if (object_label == smack_known_star.smk_known) goto out_audit; /* * An object can be accessed in any way by a subject * with the same label. */ - if (subject_label == object_label || - strcmp(subject_label, object_label) == 0) + if (subject_label == object_label) goto out_audit; /* * A hat subject can read any object. * A floor object can be read by any subject. */ if ((request & MAY_ANYREAD) == request) { - if (object_label == smack_known_floor.smk_known || - strcmp(object_label, smack_known_floor.smk_known) == 0) + if (object_label == smack_known_floor.smk_known) goto out_audit; - if (subject_label == smack_known_hat.smk_known || - strcmp(subject_label, smack_known_hat.smk_known) == 0) + if (subject_label == smack_known_hat.smk_known) goto out_audit; } /* @@ -184,8 +173,9 @@ int smk_access(char *subject_label, char *object_label, int request, * good. A negative response from smk_access_entry() * indicates there is no entry for this pair. */ + skp = smk_find_entry(subject_label); rcu_read_lock(); - may = smk_access_entry(subject_label, object_label, &smack_rule_list); + may = smk_access_entry(subject_label, object_label, &skp->smk_rules); rcu_read_unlock(); if (may > 0 && (request & may) == request) @@ -344,17 +334,32 @@ void smack_log(char *subject_label, char *object_label, int request, static DEFINE_MUTEX(smack_known_lock); /** - * smk_import_entry - import a label, return the list entry + * smk_find_entry - find a label on the list, return the list entry * @string: a text string that might be a Smack label - * @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. */ -struct smack_known *smk_import_entry(const char *string, int len) +struct smack_known *smk_find_entry(const char *string) { struct smack_known *skp; - char smack[SMK_LABELLEN]; + + list_for_each_entry_rcu(skp, &smack_known_list, list) { + if (strncmp(skp->smk_known, string, SMK_MAXLEN) == 0) + return skp; + } + + return NULL; +} + +/** + * smk_parse_smack - parse smack label from a text string + * @string: a text string that might contain a Smack label + * @len: the maximum size, or zero if it is NULL terminated. + * @smack: parsed smack label, or NULL if parse error + */ +void smk_parse_smack(const char *string, int len, char *smack) +{ int found; int i; @@ -372,27 +377,38 @@ struct smack_known *smk_import_entry(const char *string, int len) } else smack[i] = string[i]; } +} + +/** + * smk_import_entry - import a label, return the list entry + * @string: a text string that might be a Smack label + * @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. + */ +struct smack_known *smk_import_entry(const char *string, int len) +{ + struct smack_known *skp; + char smack[SMK_LABELLEN]; + smk_parse_smack(string, len, smack); if (smack[0] == '\0') return NULL; mutex_lock(&smack_known_lock); - found = 0; - list_for_each_entry_rcu(skp, &smack_known_list, list) { - if (strncmp(skp->smk_known, smack, SMK_MAXLEN) == 0) { - found = 1; - break; - } - } + skp = smk_find_entry(smack); - if (found == 0) { + if (skp == NULL) { skp = kzalloc(sizeof(struct smack_known), GFP_KERNEL); if (skp != NULL) { strncpy(skp->smk_known, smack, SMK_MAXLEN); skp->smk_secid = smack_next_secid++; skp->smk_cipso = NULL; + INIT_LIST_HEAD(&skp->smk_rules); spin_lock_init(&skp->smk_cipsolock); + mutex_init(&skp->smk_rules_lock); /* * Make sure that the entry is actually * filled before putting it on the list. @@ -480,19 +496,12 @@ u32 smack_to_secid(const char *smack) * smack_from_cipso - find the Smack label associated with a CIPSO option * @level: Bell & LaPadula level from the network * @cp: Bell & LaPadula categories from the network - * @result: where to put the Smack value * * This is a simple lookup in the label table. * - * This is an odd duck as far as smack handling goes in that - * it sends back a copy of the smack label rather than a pointer - * to the master list. This is done because it is possible for - * a foreign host to send a smack label that is new to this - * machine and hence not on the list. That would not be an - * issue except that adding an entry to the master list can't - * be done at that point. + * Return the matching label from the label list or NULL. */ -void smack_from_cipso(u32 level, char *cp, char *result) +char *smack_from_cipso(u32 level, char *cp) { struct smack_known *kp; char *final = NULL; @@ -509,12 +518,13 @@ void smack_from_cipso(u32 level, char *cp, char *result) final = kp->smk_known; spin_unlock_bh(&kp->smk_cipsolock); + + if (final != NULL) + break; } rcu_read_unlock(); - if (final == NULL) - final = smack_known_huh.smk_known; - strncpy(result, final, SMK_MAXLEN); - return; + + return final; } /** diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index b9c5e149903..7db62b48eb4 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -5,12 +5,13 @@ * * Authors: * Casey Schaufler <casey@schaufler-ca.com> - * Jarkko Sakkinen <ext-jarkko.2.sakkinen@nokia.com> + * Jarkko Sakkinen <jarkko.sakkinen@intel.com> * * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com> * Copyright (C) 2009 Hewlett-Packard Development Company, L.P. * Paul Moore <paul@paul-moore.com> * Copyright (C) 2010 Nokia Corporation + * Copyright (C) 2011 Intel Corporation. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2, @@ -34,6 +35,7 @@ #include <linux/audit.h> #include <linux/magic.h> #include <linux/dcache.h> +#include <linux/personality.h> #include "smack.h" #define task_security(task) (task_cred_xxx((task), security)) @@ -441,11 +443,17 @@ static int smack_sb_umount(struct vfsmount *mnt, int flags) * BPRM hooks */ +/** + * smack_bprm_set_creds - set creds for exec + * @bprm: the exec information + * + * Returns 0 if it gets a blob, -ENOMEM otherwise + */ static int smack_bprm_set_creds(struct linux_binprm *bprm) { - struct task_smack *tsp = bprm->cred->security; + struct inode *inode = bprm->file->f_path.dentry->d_inode; + struct task_smack *bsp = bprm->cred->security; struct inode_smack *isp; - struct dentry *dp; int rc; rc = cap_bprm_set_creds(bprm); @@ -455,20 +463,48 @@ static int smack_bprm_set_creds(struct linux_binprm *bprm) if (bprm->cred_prepared) return 0; - if (bprm->file == NULL || bprm->file->f_dentry == NULL) + isp = inode->i_security; + if (isp->smk_task == NULL || isp->smk_task == bsp->smk_task) return 0; - dp = bprm->file->f_dentry; + if (bprm->unsafe) + return -EPERM; - if (dp->d_inode == NULL) - return 0; + bsp->smk_task = isp->smk_task; + bprm->per_clear |= PER_CLEAR_ON_SETID; - isp = dp->d_inode->i_security; + return 0; +} - if (isp->smk_task != NULL) - tsp->smk_task = isp->smk_task; +/** + * smack_bprm_committing_creds - Prepare to install the new credentials + * from bprm. + * + * @bprm: binprm for exec + */ +static void smack_bprm_committing_creds(struct linux_binprm *bprm) +{ + struct task_smack *bsp = bprm->cred->security; - return 0; + if (bsp->smk_task != bsp->smk_forked) + current->pdeath_signal = 0; +} + +/** + * smack_bprm_secureexec - Return the decision to use secureexec. + * @bprm: binprm for exec + * + * Returns 0 on success. + */ +static int smack_bprm_secureexec(struct linux_binprm *bprm) +{ + struct task_smack *tsp = current_security(); + int ret = cap_bprm_secureexec(bprm); + + if (!ret && (tsp->smk_task != tsp->smk_forked)) + ret = 1; + + return ret; } /* @@ -516,6 +552,8 @@ static int smack_inode_init_security(struct inode *inode, struct inode *dir, const struct qstr *qstr, char **name, void **value, size_t *len) { + struct smack_known *skp; + char *csp = smk_of_current(); char *isp = smk_of_inode(inode); char *dsp = smk_of_inode(dir); int may; @@ -527,8 +565,9 @@ static int smack_inode_init_security(struct inode *inode, struct inode *dir, } if (value) { + skp = smk_find_entry(csp); rcu_read_lock(); - may = smk_access_entry(smk_of_current(), dsp, &smack_rule_list); + may = smk_access_entry(csp, dsp, &skp->smk_rules); rcu_read_unlock(); /* @@ -841,7 +880,7 @@ static void smack_inode_post_setxattr(struct dentry *dentry, const char *name, return; } -/* +/** * smack_inode_getxattr - Smack check on getxattr * @dentry: the object * @name: unused @@ -858,7 +897,7 @@ static int smack_inode_getxattr(struct dentry *dentry, const char *name) return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ, &ad); } -/* +/** * smack_inode_removexattr - Smack check on removexattr * @dentry: the object * @name: name of the attribute @@ -1088,36 +1127,31 @@ static int smack_file_lock(struct file *file, unsigned int cmd) * @cmd: what action to check * @arg: unused * + * Generally these operations are harmless. + * File locking operations present an obvious mechanism + * for passing information, so they require write access. + * * Returns 0 if current has access, error code otherwise */ static int smack_file_fcntl(struct file *file, unsigned int cmd, unsigned long arg) { struct smk_audit_info ad; - int rc; + int rc = 0; - smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); - smk_ad_setfield_u_fs_path(&ad, file->f_path); switch (cmd) { - case F_DUPFD: - case F_GETFD: - case F_GETFL: case F_GETLK: - case F_GETOWN: - case F_GETSIG: - rc = smk_curacc(file->f_security, MAY_READ, &ad); - break; - case F_SETFD: - case F_SETFL: case F_SETLK: case F_SETLKW: case F_SETOWN: case F_SETSIG: + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); + smk_ad_setfield_u_fs_path(&ad, file->f_path); rc = smk_curacc(file->f_security, MAY_WRITE, &ad); break; default: - rc = smk_curacc(file->f_security, MAY_READWRITE, &ad); + break; } return rc; @@ -1138,6 +1172,7 @@ static int smack_file_mmap(struct file *file, unsigned long flags, unsigned long addr, unsigned long addr_only) { + struct smack_known *skp; struct smack_rule *srp; struct task_smack *tsp; char *sp; @@ -1170,6 +1205,7 @@ static int smack_file_mmap(struct file *file, tsp = current_security(); sp = smk_of_current(); + skp = smk_find_entry(sp); rc = 0; rcu_read_lock(); @@ -1177,15 +1213,8 @@ static int smack_file_mmap(struct file *file, * For each Smack rule associated with the subject * label verify that the SMACK64MMAP also has access * to that rule's object label. - * - * Because neither of the labels comes - * from the networking code it is sufficient - * to compare pointers. */ - list_for_each_entry_rcu(srp, &smack_rule_list, list) { - if (srp->smk_subject != sp) - continue; - + list_for_each_entry_rcu(srp, &skp->smk_rules, list) { osmack = srp->smk_object; /* * Matching labels always allows access. @@ -1214,7 +1243,8 @@ static int smack_file_mmap(struct file *file, * If there isn't one a SMACK64MMAP subject * can't have as much access as current. */ - mmay = smk_access_entry(msmack, osmack, &smack_rule_list); + skp = smk_find_entry(msmack); + mmay = smk_access_entry(msmack, osmack, &skp->smk_rules); if (mmay == -ENOENT) { rc = -EACCES; break; @@ -1315,6 +1345,24 @@ static int smack_file_receive(struct file *file) return smk_curacc(file->f_security, may, &ad); } +/** + * smack_dentry_open - Smack dentry open processing + * @file: the object + * @cred: unused + * + * Set the security blob in the file structure. + * + * Returns 0 + */ +static int smack_dentry_open(struct file *file, const struct cred *cred) +{ + struct inode_smack *isp = file->f_path.dentry->d_inode->i_security; + + file->f_security = isp->smk_inode; + + return 0; +} + /* * Task hooks */ @@ -1455,15 +1503,17 @@ static int smack_kernel_create_files_as(struct cred *new, /** * smk_curacc_on_task - helper to log task related access * @p: the task object - * @access : the access requested + * @access: the access requested + * @caller: name of the calling function for audit * * Return 0 if access is permitted */ -static int smk_curacc_on_task(struct task_struct *p, int access) +static int smk_curacc_on_task(struct task_struct *p, int access, + const char *caller) { struct smk_audit_info ad; - smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK); + smk_ad_init(&ad, caller, LSM_AUDIT_DATA_TASK); smk_ad_setfield_u_tsk(&ad, p); return smk_curacc(smk_of_task(task_security(p)), access, &ad); } @@ -1477,7 +1527,7 @@ static int smk_curacc_on_task(struct task_struct *p, int access) */ static int smack_task_setpgid(struct task_struct *p, pid_t pgid) { - return smk_curacc_on_task(p, MAY_WRITE); + return smk_curacc_on_task(p, MAY_WRITE, __func__); } /** @@ -1488,7 +1538,7 @@ static int smack_task_setpgid(struct task_struct *p, pid_t pgid) */ static int smack_task_getpgid(struct task_struct *p) { - return smk_curacc_on_task(p, MAY_READ); + return smk_curacc_on_task(p, MAY_READ, __func__); } /** @@ -1499,7 +1549,7 @@ static int smack_task_getpgid(struct task_struct *p) */ static int smack_task_getsid(struct task_struct *p) { - return smk_curacc_on_task(p, MAY_READ); + return smk_curacc_on_task(p, MAY_READ, __func__); } /** @@ -1527,7 +1577,7 @@ static int smack_task_setnice(struct task_struct *p, int nice) rc = cap_task_setnice(p, nice); if (rc == 0) - rc = smk_curacc_on_task(p, MAY_WRITE); + rc = smk_curacc_on_task(p, MAY_WRITE, __func__); return rc; } @@ -1544,7 +1594,7 @@ static int smack_task_setioprio(struct task_struct *p, int ioprio) rc = cap_task_setioprio(p, ioprio); if (rc == 0) - rc = smk_curacc_on_task(p, MAY_WRITE); + rc = smk_curacc_on_task(p, MAY_WRITE, __func__); return rc; } @@ -1556,7 +1606,7 @@ static int smack_task_setioprio(struct task_struct *p, int ioprio) */ static int smack_task_getioprio(struct task_struct *p) { - return smk_curacc_on_task(p, MAY_READ); + return smk_curacc_on_task(p, MAY_READ, __func__); } /** @@ -1573,7 +1623,7 @@ static int smack_task_setscheduler(struct task_struct *p) rc = cap_task_setscheduler(p); if (rc == 0) - rc = smk_curacc_on_task(p, MAY_WRITE); + rc = smk_curacc_on_task(p, MAY_WRITE, __func__); return rc; } @@ -1585,7 +1635,7 @@ static int smack_task_setscheduler(struct task_struct *p) */ static int smack_task_getscheduler(struct task_struct *p) { - return smk_curacc_on_task(p, MAY_READ); + return smk_curacc_on_task(p, MAY_READ, __func__); } /** @@ -1596,7 +1646,7 @@ static int smack_task_getscheduler(struct task_struct *p) */ static int smack_task_movememory(struct task_struct *p) { - return smk_curacc_on_task(p, MAY_WRITE); + return smk_curacc_on_task(p, MAY_WRITE, __func__); } /** @@ -1711,7 +1761,7 @@ static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags) ssp->smk_in = csp; ssp->smk_out = csp; - ssp->smk_packet[0] = '\0'; + ssp->smk_packet = NULL; sk->sk_security = ssp; @@ -2753,6 +2803,7 @@ static int smack_unix_stream_connect(struct sock *sock, { struct socket_smack *ssp = sock->sk_security; struct socket_smack *osp = other->sk_security; + struct socket_smack *nsp = newsk->sk_security; struct smk_audit_info ad; int rc = 0; @@ -2762,6 +2813,14 @@ static int smack_unix_stream_connect(struct sock *sock, if (!capable(CAP_MAC_OVERRIDE)) rc = smk_access(ssp->smk_out, osp->smk_in, MAY_WRITE, &ad); + /* + * Cross reference the peer labels for SO_PEERSEC. + */ + if (rc == 0) { + nsp->smk_packet = ssp->smk_out; + ssp->smk_packet = osp->smk_out; + } + return rc; } @@ -2813,16 +2872,17 @@ static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg, return smack_netlabel_send(sock->sk, sip); } - /** * smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat pair to smack * @sap: netlabel secattr - * @sip: where to put the result + * @ssp: socket security information * - * Copies a smack label into sip + * Returns a pointer to a Smack label found on the label list. */ -static void smack_from_secattr(struct netlbl_lsm_secattr *sap, char *sip) +static char *smack_from_secattr(struct netlbl_lsm_secattr *sap, + struct socket_smack *ssp) { + struct smack_known *skp; char smack[SMK_LABELLEN]; char *sp; int pcat; @@ -2852,15 +2912,43 @@ static void smack_from_secattr(struct netlbl_lsm_secattr *sap, char *sip) * we are already done. WeeHee. */ if (sap->attr.mls.lvl == smack_cipso_direct) { - memcpy(sip, smack, SMK_MAXLEN); - return; + /* + * The label sent is usually on the label list. + * + * If it is not we may still want to allow the + * delivery. + * + * If the recipient is accepting all packets + * because it is using the star ("*") label + * for SMACK64IPIN provide the web ("@") label + * so that a directed response will succeed. + * This is not very correct from a MAC point + * of view, but gets around the problem that + * locking prevents adding the newly discovered + * label to the list. + * The case where the recipient is not using + * the star label should obviously fail. + * The easy way to do this is to provide the + * star label as the subject label. + */ + skp = smk_find_entry(smack); + if (skp != NULL) + return skp->smk_known; + if (ssp != NULL && + ssp->smk_in == smack_known_star.smk_known) + return smack_known_web.smk_known; + return smack_known_star.smk_known; } /* * Look it up in the supplied table if it is not * a direct mapping. */ - smack_from_cipso(sap->attr.mls.lvl, smack, sip); - return; + sp = smack_from_cipso(sap->attr.mls.lvl, smack); + if (sp != NULL) + return sp; + if (ssp != NULL && ssp->smk_in == smack_known_star.smk_known) + return smack_known_web.smk_known; + return smack_known_star.smk_known; } if ((sap->flags & NETLBL_SECATTR_SECID) != 0) { /* @@ -2875,16 +2963,14 @@ static void smack_from_secattr(struct netlbl_lsm_secattr *sap, char *sip) * secid is from a fallback. */ BUG_ON(sp == NULL); - strncpy(sip, sp, SMK_MAXLEN); - return; + return sp; } /* * Without guidance regarding the smack value * for the packet fall back on the network * ambient value. */ - strncpy(sip, smack_net_ambient, SMK_MAXLEN); - return; + return smack_net_ambient; } /** @@ -2898,7 +2984,6 @@ static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) { struct netlbl_lsm_secattr secattr; struct socket_smack *ssp = sk->sk_security; - char smack[SMK_LABELLEN]; char *csp; int rc; struct smk_audit_info ad; @@ -2911,10 +2996,9 @@ static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) netlbl_secattr_init(&secattr); rc = netlbl_skbuff_getattr(skb, sk->sk_family, &secattr); - if (rc == 0) { - smack_from_secattr(&secattr, smack); - csp = smack; - } else + if (rc == 0) + csp = smack_from_secattr(&secattr, ssp); + else csp = smack_net_ambient; netlbl_secattr_destroy(&secattr); @@ -2951,15 +3035,19 @@ static int smack_socket_getpeersec_stream(struct socket *sock, int __user *optlen, unsigned len) { struct socket_smack *ssp; - int slen; + char *rcp = ""; + int slen = 1; int rc = 0; ssp = sock->sk->sk_security; - slen = strlen(ssp->smk_packet) + 1; + if (ssp->smk_packet != NULL) { + rcp = ssp->smk_packet; + slen = strlen(rcp) + 1; + } if (slen > len) rc = -ERANGE; - else if (copy_to_user(optval, ssp->smk_packet, slen) != 0) + else if (copy_to_user(optval, rcp, slen) != 0) rc = -EFAULT; if (put_user(slen, optlen) != 0) @@ -2982,8 +3070,8 @@ static int smack_socket_getpeersec_dgram(struct socket *sock, { struct netlbl_lsm_secattr secattr; - struct socket_smack *sp; - char smack[SMK_LABELLEN]; + struct socket_smack *ssp = NULL; + char *sp; int family = PF_UNSPEC; u32 s = 0; /* 0 is the invalid secid */ int rc; @@ -2998,17 +3086,19 @@ static int smack_socket_getpeersec_dgram(struct socket *sock, family = sock->sk->sk_family; if (family == PF_UNIX) { - sp = sock->sk->sk_security; - s = smack_to_secid(sp->smk_out); + ssp = sock->sk->sk_security; + s = smack_to_secid(ssp->smk_out); } else if (family == PF_INET || family == PF_INET6) { /* * Translate what netlabel gave us. */ + if (sock != NULL && sock->sk != NULL) + ssp = sock->sk->sk_security; netlbl_secattr_init(&secattr); rc = netlbl_skbuff_getattr(skb, family, &secattr); if (rc == 0) { - smack_from_secattr(&secattr, smack); - s = smack_to_secid(smack); + sp = smack_from_secattr(&secattr, ssp); + s = smack_to_secid(sp); } netlbl_secattr_destroy(&secattr); } @@ -3056,7 +3146,7 @@ static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb, struct netlbl_lsm_secattr secattr; struct sockaddr_in addr; struct iphdr *hdr; - char smack[SMK_LABELLEN]; + char *sp; int rc; struct smk_audit_info ad; @@ -3067,9 +3157,9 @@ static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb, netlbl_secattr_init(&secattr); rc = netlbl_skbuff_getattr(skb, family, &secattr); if (rc == 0) - smack_from_secattr(&secattr, smack); + sp = smack_from_secattr(&secattr, ssp); else - strncpy(smack, smack_known_huh.smk_known, SMK_MAXLEN); + sp = smack_known_huh.smk_known; netlbl_secattr_destroy(&secattr); #ifdef CONFIG_AUDIT @@ -3082,7 +3172,7 @@ static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb, * Receiving a packet requires that the other end be able to write * here. Read access is not required. */ - rc = smk_access(smack, ssp->smk_in, MAY_WRITE, &ad); + rc = smk_access(sp, ssp->smk_in, MAY_WRITE, &ad); if (rc != 0) return rc; @@ -3090,7 +3180,7 @@ static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb, * Save the peer's label in the request_sock so we can later setup * smk_packet in the child socket so that SO_PEERCRED can report it. */ - req->peer_secid = smack_to_secid(smack); + req->peer_secid = smack_to_secid(sp); /* * We need to decide if we want to label the incoming connection here @@ -3103,7 +3193,7 @@ static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb, if (smack_host_label(&addr) == NULL) { rcu_read_unlock(); netlbl_secattr_init(&secattr); - smack_to_secattr(smack, &secattr); + smack_to_secattr(sp, &secattr); rc = netlbl_req_setattr(req, &secattr); netlbl_secattr_destroy(&secattr); } else { @@ -3125,13 +3215,11 @@ static void smack_inet_csk_clone(struct sock *sk, const struct request_sock *req) { struct socket_smack *ssp = sk->sk_security; - char *smack; - if (req->peer_secid != 0) { - smack = smack_from_secid(req->peer_secid); - strncpy(ssp->smk_packet, smack, SMK_MAXLEN); - } else - ssp->smk_packet[0] = '\0'; + if (req->peer_secid != 0) + ssp->smk_packet = smack_from_secid(req->peer_secid); + else + ssp->smk_packet = NULL; } /* @@ -3409,6 +3497,8 @@ struct security_operations smack_ops = { .sb_umount = smack_sb_umount, .bprm_set_creds = smack_bprm_set_creds, + .bprm_committing_creds = smack_bprm_committing_creds, + .bprm_secureexec = smack_bprm_secureexec, .inode_alloc_security = smack_inode_alloc_security, .inode_free_security = smack_inode_free_security, @@ -3440,6 +3530,8 @@ struct security_operations smack_ops = { .file_send_sigiotask = smack_file_send_sigiotask, .file_receive = smack_file_receive, + .dentry_open = smack_dentry_open, + .cred_alloc_blank = smack_cred_alloc_blank, .cred_free = smack_cred_free, .cred_prepare = smack_cred_prepare, diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c index f93460156dc..5c32f36ff70 100644 --- a/security/smack/smackfs.c +++ b/security/smack/smackfs.c @@ -44,6 +44,7 @@ enum smk_inos { SMK_ONLYCAP = 9, /* the only "capable" label */ SMK_LOGGING = 10, /* logging */ SMK_LOAD_SELF = 11, /* task specific rules */ + SMK_ACCESSES = 12, /* access policy */ }; /* @@ -85,15 +86,22 @@ char *smack_onlycap; */ LIST_HEAD(smk_netlbladdr_list); + +/* + * Rule lists are maintained for each label. + * This master list is just for reading /smack/load. + */ +struct smack_master_list { + struct list_head list; + struct smack_rule *smk_rule; +}; + LIST_HEAD(smack_rule_list); static int smk_cipso_doi_value = SMACK_CIPSO_DOI_DEFAULT; const char *smack_cipso_option = SMACK_CIPSO_OPTION; - -#define SEQ_READ_FINISHED 1 - /* * Values for parsing cipso rules * SMK_DIGITLEN: Length of a digit field in a rule. @@ -159,9 +167,13 @@ static int smk_set_access(struct smack_rule *srp, struct list_head *rule_list, mutex_lock(rule_lock); + /* + * Because the object label is less likely to match + * than the subject label check it first + */ list_for_each_entry_rcu(sp, rule_list, list) { - if (sp->smk_subject == srp->smk_subject && - sp->smk_object == srp->smk_object) { + if (sp->smk_object == srp->smk_object && + sp->smk_subject == srp->smk_subject) { found = 1; sp->smk_access = srp->smk_access; break; @@ -176,6 +188,99 @@ static int smk_set_access(struct smack_rule *srp, struct list_head *rule_list, } /** + * smk_parse_rule - parse Smack rule from load string + * @data: string to be parsed whose size is SMK_LOADLEN + * @rule: Smack rule + * @import: if non-zero, import labels + */ +static int smk_parse_rule(const char *data, struct smack_rule *rule, int import) +{ + char smack[SMK_LABELLEN]; + struct smack_known *skp; + + if (import) { + rule->smk_subject = smk_import(data, 0); + if (rule->smk_subject == NULL) + return -1; + + rule->smk_object = smk_import(data + SMK_LABELLEN, 0); + if (rule->smk_object == NULL) + return -1; + } else { + smk_parse_smack(data, 0, smack); + skp = smk_find_entry(smack); + if (skp == NULL) + return -1; + rule->smk_subject = skp->smk_known; + + smk_parse_smack(data + SMK_LABELLEN, 0, smack); + skp = smk_find_entry(smack); + if (skp == NULL) + return -1; + rule->smk_object = skp->smk_known; + } + + rule->smk_access = 0; + + switch (data[SMK_LABELLEN + SMK_LABELLEN]) { + case '-': + break; + case 'r': + case 'R': + rule->smk_access |= MAY_READ; + break; + default: + return -1; + } + + switch (data[SMK_LABELLEN + SMK_LABELLEN + 1]) { + case '-': + break; + case 'w': + case 'W': + rule->smk_access |= MAY_WRITE; + break; + default: + return -1; + } + + switch (data[SMK_LABELLEN + SMK_LABELLEN + 2]) { + case '-': + break; + case 'x': + case 'X': + rule->smk_access |= MAY_EXEC; + break; + default: + return -1; + } + + switch (data[SMK_LABELLEN + SMK_LABELLEN + 3]) { + case '-': + break; + case 'a': + case 'A': + rule->smk_access |= MAY_APPEND; + break; + default: + return -1; + } + + switch (data[SMK_LABELLEN + SMK_LABELLEN + 4]) { + case '-': + break; + case 't': + case 'T': + rule->smk_access |= MAY_TRANSMUTE; + break; + default: + return -1; + } + + return 0; +} + +/** * smk_write_load_list - write() for any /smack/load * @file: file pointer, not actually used * @buf: where to get the data from @@ -197,9 +302,12 @@ static ssize_t smk_write_load_list(struct file *file, const char __user *buf, struct list_head *rule_list, struct mutex *rule_lock) { + struct smack_master_list *smlp; + struct smack_known *skp; struct smack_rule *rule; char *data; int rc = -EINVAL; + int load = 0; /* * No partial writes. @@ -234,78 +342,32 @@ static ssize_t smk_write_load_list(struct file *file, const char __user *buf, goto out; } - rule->smk_subject = smk_import(data, 0); - if (rule->smk_subject == NULL) - goto out_free_rule; - - rule->smk_object = smk_import(data + SMK_LABELLEN, 0); - if (rule->smk_object == NULL) - goto out_free_rule; - - rule->smk_access = 0; - - switch (data[SMK_LABELLEN + SMK_LABELLEN]) { - case '-': - break; - case 'r': - case 'R': - rule->smk_access |= MAY_READ; - break; - default: - goto out_free_rule; - } - - switch (data[SMK_LABELLEN + SMK_LABELLEN + 1]) { - case '-': - break; - case 'w': - case 'W': - rule->smk_access |= MAY_WRITE; - break; - default: - goto out_free_rule; - } - - switch (data[SMK_LABELLEN + SMK_LABELLEN + 2]) { - case '-': - break; - case 'x': - case 'X': - rule->smk_access |= MAY_EXEC; - break; - default: - goto out_free_rule; - } - - switch (data[SMK_LABELLEN + SMK_LABELLEN + 3]) { - case '-': - break; - case 'a': - case 'A': - rule->smk_access |= MAY_APPEND; - break; - default: + if (smk_parse_rule(data, rule, 1)) goto out_free_rule; - } - switch (data[SMK_LABELLEN + SMK_LABELLEN + 4]) { - case '-': - break; - case 't': - case 'T': - rule->smk_access |= MAY_TRANSMUTE; - break; - default: - goto out_free_rule; + if (rule_list == NULL) { + load = 1; + skp = smk_find_entry(rule->smk_subject); + rule_list = &skp->smk_rules; + rule_lock = &skp->smk_rules_lock; } rc = count; /* + * If this is "load" as opposed to "load-self" and a new rule + * it needs to get added for reporting. * smk_set_access returns true if there was already a rule * for the subject/object pair, and false if it was new. */ - if (!smk_set_access(rule, rule_list, rule_lock)) + if (load && !smk_set_access(rule, rule_list, rule_lock)) { + smlp = kzalloc(sizeof(*smlp), GFP_KERNEL); + if (smlp != NULL) { + smlp->smk_rule = rule; + list_add_rcu(&smlp->list, &smack_rule_list); + } else + rc = -ENOMEM; goto out; + } out_free_rule: kfree(rule); @@ -314,36 +376,71 @@ out: return rc; } - /* - * Seq_file read operations for /smack/load + * Core logic for smackfs seq list operations. */ -static void *load_seq_start(struct seq_file *s, loff_t *pos) +static void *smk_seq_start(struct seq_file *s, loff_t *pos, + struct list_head *head) { - if (*pos == SEQ_READ_FINISHED) + struct list_head *list; + + /* + * This is 0 the first time through. + */ + if (s->index == 0) + s->private = head; + + if (s->private == NULL) return NULL; - if (list_empty(&smack_rule_list)) + + list = s->private; + if (list_empty(list)) return NULL; - return smack_rule_list.next; + + if (s->index == 0) + return list->next; + return list; } -static void *load_seq_next(struct seq_file *s, void *v, loff_t *pos) +static void *smk_seq_next(struct seq_file *s, void *v, loff_t *pos, + struct list_head *head) { struct list_head *list = v; - if (list_is_last(list, &smack_rule_list)) { - *pos = SEQ_READ_FINISHED; + if (list_is_last(list, head)) { + s->private = NULL; return NULL; } + s->private = list->next; return list->next; } +static void smk_seq_stop(struct seq_file *s, void *v) +{ + /* No-op */ +} + +/* + * Seq_file read operations for /smack/load + */ + +static void *load_seq_start(struct seq_file *s, loff_t *pos) +{ + return smk_seq_start(s, pos, &smack_rule_list); +} + +static void *load_seq_next(struct seq_file *s, void *v, loff_t *pos) +{ + return smk_seq_next(s, v, pos, &smack_rule_list); +} + static int load_seq_show(struct seq_file *s, void *v) { struct list_head *list = v; - struct smack_rule *srp = - list_entry(list, struct smack_rule, list); + struct smack_master_list *smlp = + list_entry(list, struct smack_master_list, list); + struct smack_rule *srp = smlp->smk_rule; seq_printf(s, "%s %s", (char *)srp->smk_subject, (char *)srp->smk_object); @@ -368,16 +465,11 @@ static int load_seq_show(struct seq_file *s, void *v) return 0; } -static void load_seq_stop(struct seq_file *s, void *v) -{ - /* No-op */ -} - static const struct seq_operations load_seq_ops = { .start = load_seq_start, .next = load_seq_next, .show = load_seq_show, - .stop = load_seq_stop, + .stop = smk_seq_stop, }; /** @@ -412,8 +504,7 @@ static ssize_t smk_write_load(struct file *file, const char __user *buf, if (!capable(CAP_MAC_ADMIN)) return -EPERM; - return smk_write_load_list(file, buf, count, ppos, &smack_rule_list, - &smack_list_lock); + return smk_write_load_list(file, buf, count, ppos, NULL, NULL); } static const struct file_operations smk_load_ops = { @@ -497,28 +588,12 @@ static void smk_unlbl_ambient(char *oldambient) static void *cipso_seq_start(struct seq_file *s, loff_t *pos) { - if (*pos == SEQ_READ_FINISHED) - return NULL; - if (list_empty(&smack_known_list)) - return NULL; - - return smack_known_list.next; + return smk_seq_start(s, pos, &smack_known_list); } static void *cipso_seq_next(struct seq_file *s, void *v, loff_t *pos) { - struct list_head *list = v; - - /* - * labels with no associated cipso value wont be printed - * in cipso_seq_show - */ - if (list_is_last(list, &smack_known_list)) { - *pos = SEQ_READ_FINISHED; - return NULL; - } - - return list->next; + return smk_seq_next(s, v, pos, &smack_known_list); } /* @@ -557,16 +632,11 @@ static int cipso_seq_show(struct seq_file *s, void *v) return 0; } -static void cipso_seq_stop(struct seq_file *s, void *v) -{ - /* No-op */ -} - static const struct seq_operations cipso_seq_ops = { .start = cipso_seq_start, - .stop = cipso_seq_stop, .next = cipso_seq_next, .show = cipso_seq_show, + .stop = smk_seq_stop, }; /** @@ -711,23 +781,12 @@ static const struct file_operations smk_cipso_ops = { static void *netlbladdr_seq_start(struct seq_file *s, loff_t *pos) { - if (*pos == SEQ_READ_FINISHED) - return NULL; - if (list_empty(&smk_netlbladdr_list)) - return NULL; - return smk_netlbladdr_list.next; + return smk_seq_start(s, pos, &smk_netlbladdr_list); } static void *netlbladdr_seq_next(struct seq_file *s, void *v, loff_t *pos) { - struct list_head *list = v; - - if (list_is_last(list, &smk_netlbladdr_list)) { - *pos = SEQ_READ_FINISHED; - return NULL; - } - - return list->next; + return smk_seq_next(s, v, pos, &smk_netlbladdr_list); } #define BEBITS (sizeof(__be32) * 8) @@ -751,16 +810,11 @@ static int netlbladdr_seq_show(struct seq_file *s, void *v) return 0; } -static void netlbladdr_seq_stop(struct seq_file *s, void *v) -{ - /* No-op */ -} - static const struct seq_operations netlbladdr_seq_ops = { .start = netlbladdr_seq_start, - .stop = netlbladdr_seq_stop, .next = netlbladdr_seq_next, .show = netlbladdr_seq_show, + .stop = smk_seq_stop, }; /** @@ -1328,23 +1382,14 @@ static void *load_self_seq_start(struct seq_file *s, loff_t *pos) { struct task_smack *tsp = current_security(); - if (*pos == SEQ_READ_FINISHED) - return NULL; - if (list_empty(&tsp->smk_rules)) - return NULL; - return tsp->smk_rules.next; + return smk_seq_start(s, pos, &tsp->smk_rules); } static void *load_self_seq_next(struct seq_file *s, void *v, loff_t *pos) { struct task_smack *tsp = current_security(); - struct list_head *list = v; - if (list_is_last(list, &tsp->smk_rules)) { - *pos = SEQ_READ_FINISHED; - return NULL; - } - return list->next; + return smk_seq_next(s, v, pos, &tsp->smk_rules); } static int load_self_seq_show(struct seq_file *s, void *v) @@ -1376,16 +1421,11 @@ static int load_self_seq_show(struct seq_file *s, void *v) return 0; } -static void load_self_seq_stop(struct seq_file *s, void *v) -{ - /* No-op */ -} - static const struct seq_operations load_self_seq_ops = { .start = load_self_seq_start, .next = load_self_seq_next, .show = load_self_seq_show, - .stop = load_self_seq_stop, + .stop = smk_seq_stop, }; @@ -1425,6 +1465,44 @@ static const struct file_operations smk_load_self_ops = { .write = smk_write_load_self, .release = seq_release, }; + +/** + * smk_write_access - handle access check transaction + * @file: file pointer + * @buf: data from user space + * @count: bytes sent + * @ppos: where to start - must be 0 + */ +static ssize_t smk_write_access(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct smack_rule rule; + char *data; + int res; + + data = simple_transaction_get(file, buf, count); + if (IS_ERR(data)) + return PTR_ERR(data); + + if (count < SMK_LOADLEN || smk_parse_rule(data, &rule, 0)) + return -EINVAL; + + res = smk_access(rule.smk_subject, rule.smk_object, rule.smk_access, + NULL); + data[0] = res == 0 ? '1' : '0'; + data[1] = '\0'; + + simple_transaction_set(file, 2); + return SMK_LOADLEN; +} + +static const struct file_operations smk_access_ops = { + .write = smk_write_access, + .read = simple_transaction_read, + .release = simple_transaction_release, + .llseek = generic_file_llseek, +}; + /** * smk_fill_super - fill the /smackfs superblock * @sb: the empty superblock @@ -1459,6 +1537,8 @@ static int smk_fill_super(struct super_block *sb, void *data, int silent) "logging", &smk_logging_ops, S_IRUGO|S_IWUSR}, [SMK_LOAD_SELF] = { "load-self", &smk_load_self_ops, S_IRUGO|S_IWUGO}, + [SMK_ACCESSES] = { + "access", &smk_access_ops, S_IRUGO|S_IWUGO}, /* last one */ {""} }; @@ -1534,6 +1614,20 @@ static int __init init_smk_fs(void) smk_cipso_doi(); smk_unlbl_ambient(NULL); + mutex_init(&smack_known_floor.smk_rules_lock); + mutex_init(&smack_known_hat.smk_rules_lock); + mutex_init(&smack_known_huh.smk_rules_lock); + mutex_init(&smack_known_invalid.smk_rules_lock); + mutex_init(&smack_known_star.smk_rules_lock); + mutex_init(&smack_known_web.smk_rules_lock); + + INIT_LIST_HEAD(&smack_known_floor.smk_rules); + INIT_LIST_HEAD(&smack_known_hat.smk_rules); + INIT_LIST_HEAD(&smack_known_huh.smk_rules); + INIT_LIST_HEAD(&smack_known_invalid.smk_rules); + INIT_LIST_HEAD(&smack_known_star.smk_rules); + INIT_LIST_HEAD(&smack_known_web.smk_rules); + return err; } |