selinux: convert range transition list to a hashtab
Per https://bugzilla.redhat.com/show_bug.cgi?id=548145 there are sufficient range transition rules in modern (Fedora) policy to make mls_compute_sid a significant factor on the shmem file setup path due to the length of the range_tr list. Replace the simple range_tr list with a hashtab inside the security server to help mitigate this problem. Signed-off-by: Stephen D. Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org>
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@ -513,7 +513,8 @@ int mls_compute_sid(struct context *scontext,
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u32 specified,
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struct context *newcontext)
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{
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struct range_trans *rtr;
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struct range_trans rtr;
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struct mls_range *r;
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if (!selinux_mls_enabled)
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return 0;
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@ -521,15 +522,12 @@ int mls_compute_sid(struct context *scontext,
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switch (specified) {
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case AVTAB_TRANSITION:
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/* Look for a range transition rule. */
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for (rtr = policydb.range_tr; rtr; rtr = rtr->next) {
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if (rtr->source_type == scontext->type &&
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rtr->target_type == tcontext->type &&
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rtr->target_class == tclass) {
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/* Set the range from the rule */
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return mls_range_set(newcontext,
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&rtr->target_range);
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}
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}
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rtr.source_type = scontext->type;
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rtr.target_type = tcontext->type;
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rtr.target_class = tclass;
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r = hashtab_search(policydb.range_tr, &rtr);
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if (r)
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return mls_range_set(newcontext, r);
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/* Fallthrough */
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case AVTAB_CHANGE:
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if (tclass == policydb.process_class)
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@ -177,6 +177,21 @@ out_free_role:
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goto out;
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}
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static u32 rangetr_hash(struct hashtab *h, const void *k)
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{
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const struct range_trans *key = k;
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return (key->source_type + (key->target_type << 3) +
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(key->target_class << 5)) & (h->size - 1);
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}
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static int rangetr_cmp(struct hashtab *h, const void *k1, const void *k2)
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{
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const struct range_trans *key1 = k1, *key2 = k2;
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return (key1->source_type != key2->source_type ||
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key1->target_type != key2->target_type ||
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key1->target_class != key2->target_class);
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}
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/*
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* Initialize a policy database structure.
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*/
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@ -204,6 +219,10 @@ static int policydb_init(struct policydb *p)
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if (rc)
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goto out_free_symtab;
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p->range_tr = hashtab_create(rangetr_hash, rangetr_cmp, 256);
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if (!p->range_tr)
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goto out_free_symtab;
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ebitmap_init(&p->policycaps);
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ebitmap_init(&p->permissive_map);
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@ -408,6 +427,20 @@ static void symtab_hash_eval(struct symtab *s)
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info.slots_used, h->size, info.max_chain_len);
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}
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}
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static void rangetr_hash_eval(struct hashtab *h)
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{
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struct hashtab_info info;
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hashtab_stat(h, &info);
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printk(KERN_DEBUG "SELinux: rangetr: %d entries and %d/%d buckets used, "
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"longest chain length %d\n", h->nel,
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info.slots_used, h->size, info.max_chain_len);
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}
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#else
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static inline void rangetr_hash_eval(struct hashtab *h)
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{
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}
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#endif
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/*
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@ -612,6 +645,17 @@ static int (*destroy_f[SYM_NUM]) (void *key, void *datum, void *datap) =
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cat_destroy,
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};
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static int range_tr_destroy(void *key, void *datum, void *p)
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{
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struct mls_range *rt = datum;
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kfree(key);
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ebitmap_destroy(&rt->level[0].cat);
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ebitmap_destroy(&rt->level[1].cat);
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kfree(datum);
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cond_resched();
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return 0;
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}
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static void ocontext_destroy(struct ocontext *c, int i)
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{
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context_destroy(&c->context[0]);
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@ -632,7 +676,6 @@ void policydb_destroy(struct policydb *p)
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int i;
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struct role_allow *ra, *lra = NULL;
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struct role_trans *tr, *ltr = NULL;
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struct range_trans *rt, *lrt = NULL;
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for (i = 0; i < SYM_NUM; i++) {
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cond_resched();
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@ -693,20 +736,8 @@ void policydb_destroy(struct policydb *p)
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}
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kfree(lra);
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for (rt = p->range_tr; rt; rt = rt->next) {
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cond_resched();
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if (lrt) {
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ebitmap_destroy(&lrt->target_range.level[0].cat);
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ebitmap_destroy(&lrt->target_range.level[1].cat);
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kfree(lrt);
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}
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lrt = rt;
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}
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if (lrt) {
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ebitmap_destroy(&lrt->target_range.level[0].cat);
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ebitmap_destroy(&lrt->target_range.level[1].cat);
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kfree(lrt);
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}
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hashtab_map(p->range_tr, range_tr_destroy, NULL);
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hashtab_destroy(p->range_tr);
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if (p->type_attr_map) {
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for (i = 0; i < p->p_types.nprim; i++)
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@ -1689,7 +1720,8 @@ int policydb_read(struct policydb *p, void *fp)
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u32 len, len2, config, nprim, nel, nel2;
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char *policydb_str;
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struct policydb_compat_info *info;
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struct range_trans *rt, *lrt;
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struct range_trans *rt;
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struct mls_range *r;
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config = 0;
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@ -2122,44 +2154,61 @@ int policydb_read(struct policydb *p, void *fp)
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if (rc < 0)
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goto bad;
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nel = le32_to_cpu(buf[0]);
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lrt = NULL;
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for (i = 0; i < nel; i++) {
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rt = kzalloc(sizeof(*rt), GFP_KERNEL);
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if (!rt) {
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rc = -ENOMEM;
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goto bad;
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}
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if (lrt)
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lrt->next = rt;
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else
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p->range_tr = rt;
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rc = next_entry(buf, fp, (sizeof(u32) * 2));
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if (rc < 0)
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if (rc < 0) {
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kfree(rt);
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goto bad;
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}
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rt->source_type = le32_to_cpu(buf[0]);
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rt->target_type = le32_to_cpu(buf[1]);
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if (new_rangetr) {
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rc = next_entry(buf, fp, sizeof(u32));
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if (rc < 0)
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if (rc < 0) {
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kfree(rt);
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goto bad;
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}
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rt->target_class = le32_to_cpu(buf[0]);
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} else
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rt->target_class = p->process_class;
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if (!policydb_type_isvalid(p, rt->source_type) ||
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!policydb_type_isvalid(p, rt->target_type) ||
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!policydb_class_isvalid(p, rt->target_class)) {
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kfree(rt);
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rc = -EINVAL;
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goto bad;
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}
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rc = mls_read_range_helper(&rt->target_range, fp);
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if (rc)
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goto bad;
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if (!mls_range_isvalid(p, &rt->target_range)) {
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printk(KERN_WARNING "SELinux: rangetrans: invalid range\n");
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r = kzalloc(sizeof(*r), GFP_KERNEL);
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if (!r) {
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kfree(rt);
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rc = -ENOMEM;
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goto bad;
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}
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rc = mls_read_range_helper(r, fp);
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if (rc) {
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kfree(rt);
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kfree(r);
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goto bad;
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}
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if (!mls_range_isvalid(p, r)) {
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printk(KERN_WARNING "SELinux: rangetrans: invalid range\n");
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kfree(rt);
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kfree(r);
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goto bad;
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}
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rc = hashtab_insert(p->range_tr, rt, r);
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if (rc) {
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kfree(rt);
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kfree(r);
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goto bad;
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}
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lrt = rt;
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}
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rangetr_hash_eval(p->range_tr);
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}
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p->type_attr_map = kmalloc(p->p_types.nprim*sizeof(struct ebitmap), GFP_KERNEL);
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@ -113,8 +113,6 @@ struct range_trans {
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u32 source_type;
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u32 target_type;
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u32 target_class;
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struct mls_range target_range;
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struct range_trans *next;
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};
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/* Boolean data type */
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@ -240,8 +238,8 @@ struct policydb {
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fixed labeling behavior. */
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struct genfs *genfs;
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/* range transitions */
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struct range_trans *range_tr;
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/* range transitions table (range_trans_key -> mls_range) */
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struct hashtab *range_tr;
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/* type -> attribute reverse mapping */
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struct ebitmap *type_attr_map;
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