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Diffstat (limited to 'security/smack/smack_lsm.c')
-rw-r--r--security/smack/smack_lsm.c269
1 files changed, 227 insertions, 42 deletions
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 533bf3255d7f..123a499ded37 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -84,6 +84,56 @@ struct inode_smack *new_inode_smack(char *smack)
return isp;
}
+/**
+ * new_task_smack - allocate a task security blob
+ * @smack: a pointer to the Smack label to use in the blob
+ *
+ * Returns the new blob or NULL if there's no memory available
+ */
+static struct task_smack *new_task_smack(char *task, char *forked, gfp_t gfp)
+{
+ struct task_smack *tsp;
+
+ tsp = kzalloc(sizeof(struct task_smack), gfp);
+ if (tsp == NULL)
+ return NULL;
+
+ tsp->smk_task = task;
+ tsp->smk_forked = forked;
+ INIT_LIST_HEAD(&tsp->smk_rules);
+ mutex_init(&tsp->smk_rules_lock);
+
+ return tsp;
+}
+
+/**
+ * smk_copy_rules - copy a rule set
+ * @nhead - new rules header pointer
+ * @ohead - old rules header pointer
+ *
+ * Returns 0 on success, -ENOMEM on error
+ */
+static int smk_copy_rules(struct list_head *nhead, struct list_head *ohead,
+ gfp_t gfp)
+{
+ struct smack_rule *nrp;
+ struct smack_rule *orp;
+ int rc = 0;
+
+ INIT_LIST_HEAD(nhead);
+
+ list_for_each_entry_rcu(orp, ohead, list) {
+ nrp = kzalloc(sizeof(struct smack_rule), gfp);
+ if (nrp == NULL) {
+ rc = -ENOMEM;
+ break;
+ }
+ *nrp = *orp;
+ list_add_rcu(&nrp->list, nhead);
+ }
+ return rc;
+}
+
/*
* LSM hooks.
* We he, that is fun!
@@ -102,23 +152,17 @@ static int smack_ptrace_access_check(struct task_struct *ctp, unsigned int mode)
{
int rc;
struct smk_audit_info ad;
- char *sp, *tsp;
+ char *tsp;
rc = cap_ptrace_access_check(ctp, mode);
if (rc != 0)
return rc;
- sp = smk_of_current();
tsp = smk_of_task(task_security(ctp));
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
smk_ad_setfield_u_tsk(&ad, ctp);
- /* we won't log here, because rc can be overriden */
- rc = smk_access(sp, tsp, MAY_READWRITE, NULL);
- if (rc != 0 && capable(CAP_MAC_OVERRIDE))
- rc = 0;
-
- smack_log(sp, tsp, MAY_READWRITE, rc, &ad);
+ rc = smk_curacc(tsp, MAY_READWRITE, &ad);
return rc;
}
@@ -134,23 +178,17 @@ static int smack_ptrace_traceme(struct task_struct *ptp)
{
int rc;
struct smk_audit_info ad;
- char *sp, *tsp;
+ char *tsp;
rc = cap_ptrace_traceme(ptp);
if (rc != 0)
return rc;
+ tsp = smk_of_task(task_security(ptp));
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
smk_ad_setfield_u_tsk(&ad, ptp);
- sp = smk_of_current();
- tsp = smk_of_task(task_security(ptp));
- /* we won't log here, because rc can be overriden */
- rc = smk_access(tsp, sp, MAY_READWRITE, NULL);
- if (rc != 0 && has_capability(ptp, CAP_MAC_OVERRIDE))
- rc = 0;
-
- smack_log(tsp, sp, MAY_READWRITE, rc, &ad);
+ rc = smk_curacc(tsp, MAY_READWRITE, &ad);
return rc;
}
@@ -474,7 +512,7 @@ static int smack_inode_init_security(struct inode *inode, struct inode *dir,
{
char *isp = smk_of_inode(inode);
char *dsp = smk_of_inode(dir);
- u32 may;
+ int may;
if (name) {
*name = kstrdup(XATTR_SMACK_SUFFIX, GFP_KERNEL);
@@ -483,14 +521,17 @@ static int smack_inode_init_security(struct inode *inode, struct inode *dir,
}
if (value) {
- may = smk_access_entry(smk_of_current(), dsp);
+ rcu_read_lock();
+ may = smk_access_entry(smk_of_current(), dsp, &smack_rule_list);
+ rcu_read_unlock();
/*
* If the access rule allows transmutation and
* the directory requests transmutation then
* by all means transmute.
*/
- if (((may & MAY_TRANSMUTE) != 0) && smk_inode_transmutable(dir))
+ if (may > 0 && ((may & MAY_TRANSMUTE) != 0) &&
+ smk_inode_transmutable(dir))
isp = dsp;
*value = kstrdup(isp, GFP_KERNEL);
@@ -716,7 +757,8 @@ static int smack_inode_setxattr(struct dentry *dentry, const char *name,
if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 ||
- strcmp(name, XATTR_NAME_SMACKEXEC) == 0) {
+ strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
+ strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
if (!capable(CAP_MAC_ADMIN))
rc = -EPERM;
/*
@@ -773,6 +815,12 @@ static void smack_inode_post_setxattr(struct dentry *dentry, const char *name,
isp->smk_task = nsp;
else
isp->smk_task = smack_known_invalid.smk_known;
+ } else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
+ nsp = smk_import(value, size);
+ if (nsp != NULL)
+ isp->smk_mmap = nsp;
+ else
+ isp->smk_mmap = smack_known_invalid.smk_known;
} else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0)
isp->smk_flags |= SMK_INODE_TRANSMUTE;
@@ -815,7 +863,8 @@ static int smack_inode_removexattr(struct dentry *dentry, const char *name)
strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 ||
strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
- strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) {
+ strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0 ||
+ strcmp(name, XATTR_NAME_SMACKMMAP)) {
if (!capable(CAP_MAC_ADMIN))
rc = -EPERM;
} else
@@ -829,6 +878,7 @@ static int smack_inode_removexattr(struct dentry *dentry, const char *name)
if (rc == 0) {
isp = dentry->d_inode->i_security;
isp->smk_task = NULL;
+ isp->smk_mmap = NULL;
}
return rc;
@@ -1060,6 +1110,113 @@ static int smack_file_fcntl(struct file *file, unsigned int cmd,
}
/**
+ * smk_mmap_list_check - the mmap check
+ * @sub: subject label
+ * @obj: object label
+ * @access: access mode
+ * @local: the task specific rule list
+ *
+ * Returns 0 if acces is permitted, -EACCES otherwise
+ */
+static int smk_mmap_list_check(char *sub, char *obj, int access,
+ struct list_head *local)
+{
+ int may;
+
+ /*
+ * If there is not a global rule that
+ * allows access say no.
+ */
+ may = smk_access_entry(sub, obj, &smack_rule_list);
+ if (may == -ENOENT || (may & access) != access)
+ return -EACCES;
+ /*
+ * If there is a task local rule that
+ * denies access say no.
+ */
+ may = smk_access_entry(sub, obj, local);
+ if (may != -ENOENT && (may & access) != access)
+ return -EACCES;
+
+ return 0;
+}
+
+/**
+ * smack_file_mmap :
+ * Check permissions for a mmap operation. The @file may be NULL, e.g.
+ * if mapping anonymous memory.
+ * @file contains the file structure for file to map (may be NULL).
+ * @reqprot contains the protection requested by the application.
+ * @prot contains the protection that will be applied by the kernel.
+ * @flags contains the operational flags.
+ * Return 0 if permission is granted.
+ */
+static int smack_file_mmap(struct file *file,
+ unsigned long reqprot, unsigned long prot,
+ unsigned long flags, unsigned long addr,
+ unsigned long addr_only)
+{
+ struct smack_rule *srp;
+ struct task_smack *tsp;
+ char *sp;
+ char *msmack;
+ struct inode_smack *isp;
+ struct dentry *dp;
+ int rc;
+
+ /* do DAC check on address space usage */
+ rc = cap_file_mmap(file, reqprot, prot, flags, addr, addr_only);
+ if (rc || addr_only)
+ return rc;
+
+ if (file == NULL || file->f_dentry == NULL)
+ return 0;
+
+ dp = file->f_dentry;
+
+ if (dp->d_inode == NULL)
+ return 0;
+
+ isp = dp->d_inode->i_security;
+ if (isp->smk_mmap == NULL)
+ return 0;
+ msmack = isp->smk_mmap;
+
+ tsp = current_security();
+ sp = smk_of_current();
+ rc = 0;
+
+ rcu_read_lock();
+ /*
+ * 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;
+ /*
+ * Matching labels always allows access.
+ */
+ if (msmack == srp->smk_object)
+ continue;
+
+ rc = smk_mmap_list_check(msmack, srp->smk_object,
+ srp->smk_access, &tsp->smk_rules);
+ if (rc != 0)
+ break;
+ }
+
+ rcu_read_unlock();
+
+ return rc;
+}
+
+/**
* smack_file_set_fowner - set the file security blob value
* @file: object in question
*
@@ -1095,6 +1252,7 @@ static int smack_file_send_sigiotask(struct task_struct *tsk,
* struct fown_struct is never outside the context of a struct file
*/
file = container_of(fown, struct file, f_owner);
+
/* we don't log here as rc can be overriden */
rc = smk_access(file->f_security, tsp, MAY_WRITE, NULL);
if (rc != 0 && has_capability(tsk, CAP_MAC_OVERRIDE))
@@ -1145,9 +1303,14 @@ static int smack_file_receive(struct file *file)
*/
static int smack_cred_alloc_blank(struct cred *cred, gfp_t gfp)
{
- cred->security = kzalloc(sizeof(struct task_smack), gfp);
- if (cred->security == NULL)
+ struct task_smack *tsp;
+
+ tsp = new_task_smack(NULL, NULL, gfp);
+ if (tsp == NULL)
return -ENOMEM;
+
+ cred->security = tsp;
+
return 0;
}
@@ -1156,13 +1319,24 @@ static int smack_cred_alloc_blank(struct cred *cred, gfp_t gfp)
* smack_cred_free - "free" task-level security credentials
* @cred: the credentials in question
*
- * Smack isn't using copies of blobs. Everyone
- * points to an immutable list. The blobs never go away.
- * There is no leak here.
*/
static void smack_cred_free(struct cred *cred)
{
- kfree(cred->security);
+ struct task_smack *tsp = cred->security;
+ struct smack_rule *rp;
+ struct list_head *l;
+ struct list_head *n;
+
+ if (tsp == NULL)
+ return;
+ cred->security = NULL;
+
+ list_for_each_safe(l, n, &tsp->smk_rules) {
+ rp = list_entry(l, struct smack_rule, list);
+ list_del(&rp->list);
+ kfree(rp);
+ }
+ kfree(tsp);
}
/**
@@ -1178,13 +1352,16 @@ static int smack_cred_prepare(struct cred *new, const struct cred *old,
{
struct task_smack *old_tsp = old->security;
struct task_smack *new_tsp;
+ int rc;
- new_tsp = kzalloc(sizeof(struct task_smack), gfp);
+ new_tsp = new_task_smack(old_tsp->smk_task, old_tsp->smk_task, gfp);
if (new_tsp == NULL)
return -ENOMEM;
- new_tsp->smk_task = old_tsp->smk_task;
- new_tsp->smk_forked = old_tsp->smk_task;
+ rc = smk_copy_rules(&new_tsp->smk_rules, &old_tsp->smk_rules, gfp);
+ if (rc != 0)
+ return rc;
+
new->security = new_tsp;
return 0;
}
@@ -1203,6 +1380,11 @@ static void smack_cred_transfer(struct cred *new, const struct cred *old)
new_tsp->smk_task = old_tsp->smk_task;
new_tsp->smk_forked = old_tsp->smk_task;
+ mutex_init(&new_tsp->smk_rules_lock);
+ INIT_LIST_HEAD(&new_tsp->smk_rules);
+
+
+ /* cbs copy rule list */
}
/**
@@ -2419,6 +2601,7 @@ static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
}
}
isp->smk_task = smk_fetch(XATTR_NAME_SMACKEXEC, inode, dp);
+ isp->smk_mmap = smk_fetch(XATTR_NAME_SMACKMMAP, inode, dp);
dput(dp);
break;
@@ -2478,6 +2661,7 @@ static int smack_getprocattr(struct task_struct *p, char *name, char **value)
static int smack_setprocattr(struct task_struct *p, char *name,
void *value, size_t size)
{
+ int rc;
struct task_smack *tsp;
struct task_smack *oldtsp;
struct cred *new;
@@ -2513,13 +2697,16 @@ static int smack_setprocattr(struct task_struct *p, char *name,
new = prepare_creds();
if (new == NULL)
return -ENOMEM;
- tsp = kzalloc(sizeof(struct task_smack), GFP_KERNEL);
+
+ tsp = new_task_smack(newsmack, oldtsp->smk_forked, GFP_KERNEL);
if (tsp == NULL) {
kfree(new);
return -ENOMEM;
}
- tsp->smk_task = newsmack;
- tsp->smk_forked = oldtsp->smk_forked;
+ rc = smk_copy_rules(&tsp->smk_rules, &oldtsp->smk_rules, GFP_KERNEL);
+ if (rc != 0)
+ return rc;
+
new->security = tsp;
commit_creds(new);
return size;
@@ -3221,6 +3408,7 @@ struct security_operations smack_ops = {
.file_ioctl = smack_file_ioctl,
.file_lock = smack_file_lock,
.file_fcntl = smack_file_fcntl,
+ .file_mmap = smack_file_mmap,
.file_set_fowner = smack_file_set_fowner,
.file_send_sigiotask = smack_file_send_sigiotask,
.file_receive = smack_file_receive,
@@ -3334,23 +3522,20 @@ static __init int smack_init(void)
struct cred *cred;
struct task_smack *tsp;
- tsp = kzalloc(sizeof(struct task_smack), GFP_KERNEL);
+ if (!security_module_enable(&smack_ops))
+ return 0;
+
+ tsp = new_task_smack(smack_known_floor.smk_known,
+ smack_known_floor.smk_known, GFP_KERNEL);
if (tsp == NULL)
return -ENOMEM;
- if (!security_module_enable(&smack_ops)) {
- kfree(tsp);
- return 0;
- }
-
printk(KERN_INFO "Smack: Initializing.\n");
/*
* Set the security state for the initial task.
*/
cred = (struct cred *) current->cred;
- tsp->smk_forked = smack_known_floor.smk_known;
- tsp->smk_task = smack_known_floor.smk_known;
cred->security = tsp;
/* initialize the smack_know_list */