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Diffstat (limited to 'security/smack/smack_lsm.c')
-rw-r--r--security/smack/smack_lsm.c58
1 files changed, 56 insertions, 2 deletions
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index c2d66ca1127a..ff81026f6ddb 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -326,6 +326,7 @@ static struct task_smack *new_task_smack(struct smack_known *task,
tsp->smk_task = task;
tsp->smk_forked = forked;
INIT_LIST_HEAD(&tsp->smk_rules);
+ INIT_LIST_HEAD(&tsp->smk_relabel);
mutex_init(&tsp->smk_rules_lock);
return tsp;
@@ -361,6 +362,35 @@ static int smk_copy_rules(struct list_head *nhead, struct list_head *ohead,
}
/**
+ * smk_copy_relabel - copy smk_relabel labels list
+ * @nhead: new rules header pointer
+ * @ohead: old rules header pointer
+ * @gfp: type of the memory for the allocation
+ *
+ * Returns 0 on success, -ENOMEM on error
+ */
+static int smk_copy_relabel(struct list_head *nhead, struct list_head *ohead,
+ gfp_t gfp)
+{
+ struct smack_known_list_elem *nklep;
+ struct smack_known_list_elem *oklep;
+
+ INIT_LIST_HEAD(nhead);
+
+ list_for_each_entry(oklep, ohead, list) {
+ nklep = kzalloc(sizeof(struct smack_known_list_elem), gfp);
+ if (nklep == NULL) {
+ smk_destroy_label_list(nhead);
+ return -ENOMEM;
+ }
+ nklep->smk_label = oklep->smk_label;
+ list_add(&nklep->list, nhead);
+ }
+
+ return 0;
+}
+
+/**
* smk_ptrace_mode - helper function for converting PTRACE_MODE_* into MAY_*
* @mode - input mode in form of PTRACE_MODE_*
*
@@ -1922,6 +1952,8 @@ static void smack_cred_free(struct cred *cred)
return;
cred->security = NULL;
+ smk_destroy_label_list(&tsp->smk_relabel);
+
list_for_each_safe(l, n, &tsp->smk_rules) {
rp = list_entry(l, struct smack_rule, list);
list_del(&rp->list);
@@ -1953,6 +1985,11 @@ static int smack_cred_prepare(struct cred *new, const struct cred *old,
if (rc != 0)
return rc;
+ rc = smk_copy_relabel(&new_tsp->smk_relabel, &old_tsp->smk_relabel,
+ gfp);
+ if (rc != 0)
+ return rc;
+
new->security = new_tsp;
return 0;
}
@@ -3552,9 +3589,11 @@ 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)
{
- struct task_smack *tsp;
+ struct task_smack *tsp = current_security();
struct cred *new;
struct smack_known *skp;
+ struct smack_known_list_elem *sklep;
+ int rc;
/*
* Changing another process' Smack value is too dangerous
@@ -3563,7 +3602,7 @@ static int smack_setprocattr(struct task_struct *p, char *name,
if (p != current)
return -EPERM;
- if (!smack_privileged(CAP_MAC_ADMIN))
+ if (!smack_privileged(CAP_MAC_ADMIN) && list_empty(&tsp->smk_relabel))
return -EPERM;
if (value == NULL || size == 0 || size >= SMK_LONGLABEL)
@@ -3582,12 +3621,27 @@ static int smack_setprocattr(struct task_struct *p, char *name,
if (skp == &smack_known_web)
return -EPERM;
+ if (!smack_privileged(CAP_MAC_ADMIN)) {
+ rc = -EPERM;
+ list_for_each_entry(sklep, &tsp->smk_relabel, list)
+ if (sklep->smk_label == skp) {
+ rc = 0;
+ break;
+ }
+ if (rc)
+ return rc;
+ }
+
new = prepare_creds();
if (new == NULL)
return -ENOMEM;
tsp = new->security;
tsp->smk_task = skp;
+ /*
+ * process can change its label only once
+ */
+ smk_destroy_label_list(&tsp->smk_relabel);
commit_creds(new);
return size;