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Diffstat (limited to 'security/selinux/ss/sidtab.c')
-rw-r--r--security/selinux/ss/sidtab.c119
1 files changed, 80 insertions, 39 deletions
diff --git a/security/selinux/ss/sidtab.c b/security/selinux/ss/sidtab.c
index eb6d27b5aeb4..59f8c09158ef 100644
--- a/security/selinux/ss/sidtab.c
+++ b/security/selinux/ss/sidtab.c
@@ -2,11 +2,12 @@
/*
* Implementation of the SID table type.
*
- * Original author: Stephen Smalley, <sds@tycho.nsa.gov>
+ * Original author: Stephen Smalley, <stephen.smalley.work@gmail.com>
* Author: Ondrej Mosnacek, <omosnacek@gmail.com>
*
* Copyright (C) 2018 Red Hat, Inc.
*/
+
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/list.h>
@@ -18,17 +19,18 @@
#include "flask.h"
#include "security.h"
#include "sidtab.h"
+#include "services.h"
struct sidtab_str_cache {
struct rcu_head rcu_member;
struct list_head lru_member;
struct sidtab_entry *parent;
u32 len;
- char str[];
+ char str[] __counted_by(len);
};
-#define index_to_sid(index) (index + SECINITSID_NUM + 1)
-#define sid_to_index(sid) (sid - (SECINITSID_NUM + 1))
+#define index_to_sid(index) ((index) + SECINITSID_NUM + 1)
+#define sid_to_index(sid) ((sid) - (SECINITSID_NUM + 1))
int sidtab_init(struct sidtab *s)
{
@@ -39,6 +41,7 @@ int sidtab_init(struct sidtab *s)
for (i = 0; i < SECINITSID_NUM; i++)
s->isids[i].set = 0;
+ s->frozen = false;
s->count = 0;
s->convert = NULL;
hash_init(s->context_to_sid);
@@ -63,7 +66,7 @@ static u32 context_to_sid(struct sidtab *s, struct context *context, u32 hash)
hash_for_each_possible_rcu(s->context_to_sid, entry, list, hash) {
if (entry->hash != hash)
continue;
- if (context_cmp(&entry->context, context)) {
+ if (context_equal(&entry->context, context)) {
sid = entry->sid;
break;
}
@@ -111,12 +114,12 @@ int sidtab_set_initial(struct sidtab *s, u32 sid, struct context *context)
int sidtab_hash_stats(struct sidtab *sidtab, char *page)
{
- int i;
+ unsigned int i;
int chain_len = 0;
int slots_used = 0;
int entries = 0;
int max_chain_len = 0;
- int cur_bucket = 0;
+ unsigned int cur_bucket = 0;
struct sidtab_entry *entry;
rcu_read_lock();
@@ -138,9 +141,11 @@ int sidtab_hash_stats(struct sidtab *sidtab, char *page)
if (chain_len > max_chain_len)
max_chain_len = chain_len;
- return scnprintf(page, PAGE_SIZE, "entries: %d\nbuckets used: %d/%d\n"
- "longest chain: %d\n", entries,
- slots_used, SIDTAB_HASH_BUCKETS, max_chain_len);
+ return scnprintf(page, PAGE_SIZE,
+ "entries: %d\nbuckets used: %d/%d\n"
+ "longest chain: %d\n",
+ entries, slots_used, SIDTAB_HASH_BUCKETS,
+ max_chain_len);
}
static u32 sidtab_level_from_count(u32 count)
@@ -160,15 +165,15 @@ static int sidtab_alloc_roots(struct sidtab *s, u32 level)
u32 l;
if (!s->roots[0].ptr_leaf) {
- s->roots[0].ptr_leaf = kzalloc(SIDTAB_NODE_ALLOC_SIZE,
- GFP_ATOMIC);
+ s->roots[0].ptr_leaf =
+ kzalloc(SIDTAB_NODE_ALLOC_SIZE, GFP_ATOMIC);
if (!s->roots[0].ptr_leaf)
return -ENOMEM;
}
for (l = 1; l <= level; ++l)
if (!s->roots[l].ptr_inner) {
- s->roots[l].ptr_inner = kzalloc(SIDTAB_NODE_ALLOC_SIZE,
- GFP_ATOMIC);
+ s->roots[l].ptr_inner =
+ kzalloc(SIDTAB_NODE_ALLOC_SIZE, GFP_ATOMIC);
if (!s->roots[l].ptr_inner)
return -ENOMEM;
s->roots[l].ptr_inner->entries[0] = s->roots[l - 1];
@@ -201,16 +206,16 @@ static struct sidtab_entry *sidtab_do_lookup(struct sidtab *s, u32 index,
if (!entry->ptr_inner) {
if (alloc)
- entry->ptr_inner = kzalloc(SIDTAB_NODE_ALLOC_SIZE,
- GFP_ATOMIC);
+ entry->ptr_inner = kzalloc(
+ SIDTAB_NODE_ALLOC_SIZE, GFP_ATOMIC);
if (!entry->ptr_inner)
return NULL;
}
}
if (!entry->ptr_leaf) {
if (alloc)
- entry->ptr_leaf = kzalloc(SIDTAB_NODE_ALLOC_SIZE,
- GFP_ATOMIC);
+ entry->ptr_leaf =
+ kzalloc(SIDTAB_NODE_ALLOC_SIZE, GFP_ATOMIC);
if (!entry->ptr_leaf)
return NULL;
}
@@ -260,8 +265,7 @@ struct sidtab_entry *sidtab_search_entry_force(struct sidtab *s, u32 sid)
return sidtab_search_core(s, sid, 1);
}
-int sidtab_context_to_sid(struct sidtab *s, struct context *context,
- u32 *sid)
+int sidtab_context_to_sid(struct sidtab *s, struct context *context, u32 *sid)
{
unsigned long flags;
u32 count, hash = context_compute_hash(context);
@@ -281,8 +285,16 @@ int sidtab_context_to_sid(struct sidtab *s, struct context *context,
if (*sid)
goto out_unlock;
+ if (unlikely(s->frozen)) {
+ /*
+ * This sidtab is now frozen - tell the caller to abort and
+ * get the new one.
+ */
+ rc = -ESTALE;
+ goto out_unlock;
+ }
+
count = s->count;
- convert = s->convert;
/* bail out if we already reached max entries */
rc = -EOVERFLOW;
@@ -306,26 +318,30 @@ int sidtab_context_to_sid(struct sidtab *s, struct context *context,
* if we are building a new sidtab, we need to convert the context
* and insert it there as well
*/
+ convert = s->convert;
if (convert) {
+ struct sidtab *target = convert->target;
+
rc = -ENOMEM;
- dst_convert = sidtab_do_lookup(convert->target, count, 1);
+ dst_convert = sidtab_do_lookup(target, count, 1);
if (!dst_convert) {
context_destroy(&dst->context);
goto out_unlock;
}
- rc = convert->func(context, &dst_convert->context,
- convert->args);
+ rc = services_convert_context(convert->args, context,
+ &dst_convert->context,
+ GFP_ATOMIC);
if (rc) {
context_destroy(&dst->context);
goto out_unlock;
}
dst_convert->sid = index_to_sid(count);
dst_convert->hash = context_compute_hash(&dst_convert->context);
- convert->target->count = count + 1;
+ target->count = count + 1;
- hash_add_rcu(convert->target->context_to_sid,
- &dst_convert->list, dst_convert->hash);
+ hash_add_rcu(target->context_to_sid, &dst_convert->list,
+ dst_convert->hash);
}
if (context->len)
@@ -359,8 +375,8 @@ static void sidtab_convert_hashtable(struct sidtab *s, u32 count)
}
static int sidtab_convert_tree(union sidtab_entry_inner *edst,
- union sidtab_entry_inner *esrc,
- u32 *pos, u32 count, u32 level,
+ union sidtab_entry_inner *esrc, u32 *pos,
+ u32 count, u32 level,
struct sidtab_convert_params *convert)
{
int rc;
@@ -368,8 +384,8 @@ static int sidtab_convert_tree(union sidtab_entry_inner *edst,
if (level != 0) {
if (!edst->ptr_inner) {
- edst->ptr_inner = kzalloc(SIDTAB_NODE_ALLOC_SIZE,
- GFP_KERNEL);
+ edst->ptr_inner =
+ kzalloc(SIDTAB_NODE_ALLOC_SIZE, GFP_KERNEL);
if (!edst->ptr_inner)
return -ENOMEM;
}
@@ -385,16 +401,18 @@ static int sidtab_convert_tree(union sidtab_entry_inner *edst,
}
} else {
if (!edst->ptr_leaf) {
- edst->ptr_leaf = kzalloc(SIDTAB_NODE_ALLOC_SIZE,
- GFP_KERNEL);
+ edst->ptr_leaf =
+ kzalloc(SIDTAB_NODE_ALLOC_SIZE, GFP_KERNEL);
if (!edst->ptr_leaf)
return -ENOMEM;
}
i = 0;
while (i < SIDTAB_LEAF_ENTRIES && *pos < count) {
- rc = convert->func(&esrc->ptr_leaf->entries[i].context,
- &edst->ptr_leaf->entries[i].context,
- convert->args);
+ rc = services_convert_context(
+ convert->args,
+ &esrc->ptr_leaf->entries[i].context,
+ &edst->ptr_leaf->entries[i].context,
+ GFP_KERNEL);
if (rc)
return rc;
(*pos)++;
@@ -464,6 +482,29 @@ int sidtab_convert(struct sidtab *s, struct sidtab_convert_params *params)
return 0;
}
+void sidtab_cancel_convert(struct sidtab *s)
+{
+ unsigned long flags;
+
+ /* cancelling policy load - disable live convert of sidtab */
+ spin_lock_irqsave(&s->lock, flags);
+ s->convert = NULL;
+ spin_unlock_irqrestore(&s->lock, flags);
+}
+
+void sidtab_freeze_begin(struct sidtab *s, unsigned long *flags)
+ __acquires(&s->lock)
+{
+ spin_lock_irqsave(&s->lock, *flags);
+ s->frozen = true;
+ s->convert = NULL;
+}
+void sidtab_freeze_end(struct sidtab *s, unsigned long *flags)
+ __releases(&s->lock)
+{
+ spin_unlock_irqrestore(&s->lock, *flags);
+}
+
static void sidtab_destroy_entry(struct sidtab_entry *entry)
{
context_destroy(&entry->context);
@@ -539,7 +580,7 @@ void sidtab_sid2str_put(struct sidtab *s, struct sidtab_entry *entry,
goto out_unlock;
}
- cache = kmalloc(sizeof(struct sidtab_str_cache) + str_len, GFP_ATOMIC);
+ cache = kmalloc(struct_size(cache, str, str_len), GFP_ATOMIC);
if (!cache)
goto out_unlock;
@@ -564,8 +605,8 @@ out_unlock:
kfree_rcu(victim, rcu_member);
}
-int sidtab_sid2str_get(struct sidtab *s, struct sidtab_entry *entry,
- char **out, u32 *out_len)
+int sidtab_sid2str_get(struct sidtab *s, struct sidtab_entry *entry, char **out,
+ u32 *out_len)
{
struct sidtab_str_cache *cache;
int rc = 0;