[Feature]add MT2731_MP2_MR2_SVN388 baseline version
Change-Id: Ief04314834b31e27effab435d3ca8ba33b499059
diff --git a/src/kernel/linux/v4.14/security/keys/keyring.c b/src/kernel/linux/v4.14/security/keys/keyring.c
new file mode 100644
index 0000000..f7cf371
--- /dev/null
+++ b/src/kernel/linux/v4.14/security/keys/keyring.c
@@ -0,0 +1,1587 @@
+/* Keyring handling
+ *
+ * Copyright (C) 2004-2005, 2008, 2013 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/security.h>
+#include <linux/seq_file.h>
+#include <linux/err.h>
+#include <keys/keyring-type.h>
+#include <keys/user-type.h>
+#include <linux/assoc_array_priv.h>
+#include <linux/uaccess.h>
+#include "internal.h"
+
+/*
+ * When plumbing the depths of the key tree, this sets a hard limit
+ * set on how deep we're willing to go.
+ */
+#define KEYRING_SEARCH_MAX_DEPTH 6
+
+/*
+ * We keep all named keyrings in a hash to speed looking them up.
+ */
+#define KEYRING_NAME_HASH_SIZE (1 << 5)
+
+/*
+ * We mark pointers we pass to the associative array with bit 1 set if
+ * they're keyrings and clear otherwise.
+ */
+#define KEYRING_PTR_SUBTYPE 0x2UL
+
+static inline bool keyring_ptr_is_keyring(const struct assoc_array_ptr *x)
+{
+ return (unsigned long)x & KEYRING_PTR_SUBTYPE;
+}
+static inline struct key *keyring_ptr_to_key(const struct assoc_array_ptr *x)
+{
+ void *object = assoc_array_ptr_to_leaf(x);
+ return (struct key *)((unsigned long)object & ~KEYRING_PTR_SUBTYPE);
+}
+static inline void *keyring_key_to_ptr(struct key *key)
+{
+ if (key->type == &key_type_keyring)
+ return (void *)((unsigned long)key | KEYRING_PTR_SUBTYPE);
+ return key;
+}
+
+static struct list_head keyring_name_hash[KEYRING_NAME_HASH_SIZE];
+static DEFINE_RWLOCK(keyring_name_lock);
+
+static inline unsigned keyring_hash(const char *desc)
+{
+ unsigned bucket = 0;
+
+ for (; *desc; desc++)
+ bucket += (unsigned char)*desc;
+
+ return bucket & (KEYRING_NAME_HASH_SIZE - 1);
+}
+
+/*
+ * The keyring key type definition. Keyrings are simply keys of this type and
+ * can be treated as ordinary keys in addition to having their own special
+ * operations.
+ */
+static int keyring_preparse(struct key_preparsed_payload *prep);
+static void keyring_free_preparse(struct key_preparsed_payload *prep);
+static int keyring_instantiate(struct key *keyring,
+ struct key_preparsed_payload *prep);
+static void keyring_revoke(struct key *keyring);
+static void keyring_destroy(struct key *keyring);
+static void keyring_describe(const struct key *keyring, struct seq_file *m);
+static long keyring_read(const struct key *keyring,
+ char __user *buffer, size_t buflen);
+
+struct key_type key_type_keyring = {
+ .name = "keyring",
+ .def_datalen = 0,
+ .preparse = keyring_preparse,
+ .free_preparse = keyring_free_preparse,
+ .instantiate = keyring_instantiate,
+ .revoke = keyring_revoke,
+ .destroy = keyring_destroy,
+ .describe = keyring_describe,
+ .read = keyring_read,
+};
+EXPORT_SYMBOL(key_type_keyring);
+
+/*
+ * Semaphore to serialise link/link calls to prevent two link calls in parallel
+ * introducing a cycle.
+ */
+static DECLARE_RWSEM(keyring_serialise_link_sem);
+
+/*
+ * Publish the name of a keyring so that it can be found by name (if it has
+ * one).
+ */
+static void keyring_publish_name(struct key *keyring)
+{
+ int bucket;
+
+ if (keyring->description) {
+ bucket = keyring_hash(keyring->description);
+
+ write_lock(&keyring_name_lock);
+
+ if (!keyring_name_hash[bucket].next)
+ INIT_LIST_HEAD(&keyring_name_hash[bucket]);
+
+ list_add_tail(&keyring->name_link,
+ &keyring_name_hash[bucket]);
+
+ write_unlock(&keyring_name_lock);
+ }
+}
+
+/*
+ * Preparse a keyring payload
+ */
+static int keyring_preparse(struct key_preparsed_payload *prep)
+{
+ return prep->datalen != 0 ? -EINVAL : 0;
+}
+
+/*
+ * Free a preparse of a user defined key payload
+ */
+static void keyring_free_preparse(struct key_preparsed_payload *prep)
+{
+}
+
+/*
+ * Initialise a keyring.
+ *
+ * Returns 0 on success, -EINVAL if given any data.
+ */
+static int keyring_instantiate(struct key *keyring,
+ struct key_preparsed_payload *prep)
+{
+ assoc_array_init(&keyring->keys);
+ /* make the keyring available by name if it has one */
+ keyring_publish_name(keyring);
+ return 0;
+}
+
+/*
+ * Multiply 64-bits by 32-bits to 96-bits and fold back to 64-bit. Ideally we'd
+ * fold the carry back too, but that requires inline asm.
+ */
+static u64 mult_64x32_and_fold(u64 x, u32 y)
+{
+ u64 hi = (u64)(u32)(x >> 32) * y;
+ u64 lo = (u64)(u32)(x) * y;
+ return lo + ((u64)(u32)hi << 32) + (u32)(hi >> 32);
+}
+
+/*
+ * Hash a key type and description.
+ */
+static unsigned long hash_key_type_and_desc(const struct keyring_index_key *index_key)
+{
+ const unsigned level_shift = ASSOC_ARRAY_LEVEL_STEP;
+ const unsigned long fan_mask = ASSOC_ARRAY_FAN_MASK;
+ const char *description = index_key->description;
+ unsigned long hash, type;
+ u32 piece;
+ u64 acc;
+ int n, desc_len = index_key->desc_len;
+
+ type = (unsigned long)index_key->type;
+
+ acc = mult_64x32_and_fold(type, desc_len + 13);
+ acc = mult_64x32_and_fold(acc, 9207);
+ for (;;) {
+ n = desc_len;
+ if (n <= 0)
+ break;
+ if (n > 4)
+ n = 4;
+ piece = 0;
+ memcpy(&piece, description, n);
+ description += n;
+ desc_len -= n;
+ acc = mult_64x32_and_fold(acc, piece);
+ acc = mult_64x32_and_fold(acc, 9207);
+ }
+
+ /* Fold the hash down to 32 bits if need be. */
+ hash = acc;
+ if (ASSOC_ARRAY_KEY_CHUNK_SIZE == 32)
+ hash ^= acc >> 32;
+
+ /* Squidge all the keyrings into a separate part of the tree to
+ * ordinary keys by making sure the lowest level segment in the hash is
+ * zero for keyrings and non-zero otherwise.
+ */
+ if (index_key->type != &key_type_keyring && (hash & fan_mask) == 0)
+ return hash | (hash >> (ASSOC_ARRAY_KEY_CHUNK_SIZE - level_shift)) | 1;
+ if (index_key->type == &key_type_keyring && (hash & fan_mask) != 0)
+ return (hash + (hash << level_shift)) & ~fan_mask;
+ return hash;
+}
+
+/*
+ * Build the next index key chunk.
+ *
+ * On 32-bit systems the index key is laid out as:
+ *
+ * 0 4 5 9...
+ * hash desclen typeptr desc[]
+ *
+ * On 64-bit systems:
+ *
+ * 0 8 9 17...
+ * hash desclen typeptr desc[]
+ *
+ * We return it one word-sized chunk at a time.
+ */
+static unsigned long keyring_get_key_chunk(const void *data, int level)
+{
+ const struct keyring_index_key *index_key = data;
+ unsigned long chunk = 0;
+ long offset = 0;
+ int desc_len = index_key->desc_len, n = sizeof(chunk);
+
+ level /= ASSOC_ARRAY_KEY_CHUNK_SIZE;
+ switch (level) {
+ case 0:
+ return hash_key_type_and_desc(index_key);
+ case 1:
+ return ((unsigned long)index_key->type << 8) | desc_len;
+ case 2:
+ if (desc_len == 0)
+ return (u8)((unsigned long)index_key->type >>
+ (ASSOC_ARRAY_KEY_CHUNK_SIZE - 8));
+ n--;
+ offset = 1;
+ default:
+ offset += sizeof(chunk) - 1;
+ offset += (level - 3) * sizeof(chunk);
+ if (offset >= desc_len)
+ return 0;
+ desc_len -= offset;
+ if (desc_len > n)
+ desc_len = n;
+ offset += desc_len;
+ do {
+ chunk <<= 8;
+ chunk |= ((u8*)index_key->description)[--offset];
+ } while (--desc_len > 0);
+
+ if (level == 2) {
+ chunk <<= 8;
+ chunk |= (u8)((unsigned long)index_key->type >>
+ (ASSOC_ARRAY_KEY_CHUNK_SIZE - 8));
+ }
+ return chunk;
+ }
+}
+
+static unsigned long keyring_get_object_key_chunk(const void *object, int level)
+{
+ const struct key *key = keyring_ptr_to_key(object);
+ return keyring_get_key_chunk(&key->index_key, level);
+}
+
+static bool keyring_compare_object(const void *object, const void *data)
+{
+ const struct keyring_index_key *index_key = data;
+ const struct key *key = keyring_ptr_to_key(object);
+
+ return key->index_key.type == index_key->type &&
+ key->index_key.desc_len == index_key->desc_len &&
+ memcmp(key->index_key.description, index_key->description,
+ index_key->desc_len) == 0;
+}
+
+/*
+ * Compare the index keys of a pair of objects and determine the bit position
+ * at which they differ - if they differ.
+ */
+static int keyring_diff_objects(const void *object, const void *data)
+{
+ const struct key *key_a = keyring_ptr_to_key(object);
+ const struct keyring_index_key *a = &key_a->index_key;
+ const struct keyring_index_key *b = data;
+ unsigned long seg_a, seg_b;
+ int level, i;
+
+ level = 0;
+ seg_a = hash_key_type_and_desc(a);
+ seg_b = hash_key_type_and_desc(b);
+ if ((seg_a ^ seg_b) != 0)
+ goto differ;
+
+ /* The number of bits contributed by the hash is controlled by a
+ * constant in the assoc_array headers. Everything else thereafter we
+ * can deal with as being machine word-size dependent.
+ */
+ level += ASSOC_ARRAY_KEY_CHUNK_SIZE / 8;
+ seg_a = a->desc_len;
+ seg_b = b->desc_len;
+ if ((seg_a ^ seg_b) != 0)
+ goto differ;
+
+ /* The next bit may not work on big endian */
+ level++;
+ seg_a = (unsigned long)a->type;
+ seg_b = (unsigned long)b->type;
+ if ((seg_a ^ seg_b) != 0)
+ goto differ;
+
+ level += sizeof(unsigned long);
+ if (a->desc_len == 0)
+ goto same;
+
+ i = 0;
+ if (((unsigned long)a->description | (unsigned long)b->description) &
+ (sizeof(unsigned long) - 1)) {
+ do {
+ seg_a = *(unsigned long *)(a->description + i);
+ seg_b = *(unsigned long *)(b->description + i);
+ if ((seg_a ^ seg_b) != 0)
+ goto differ_plus_i;
+ i += sizeof(unsigned long);
+ } while (i < (a->desc_len & (sizeof(unsigned long) - 1)));
+ }
+
+ for (; i < a->desc_len; i++) {
+ seg_a = *(unsigned char *)(a->description + i);
+ seg_b = *(unsigned char *)(b->description + i);
+ if ((seg_a ^ seg_b) != 0)
+ goto differ_plus_i;
+ }
+
+same:
+ return -1;
+
+differ_plus_i:
+ level += i;
+differ:
+ i = level * 8 + __ffs(seg_a ^ seg_b);
+ return i;
+}
+
+/*
+ * Free an object after stripping the keyring flag off of the pointer.
+ */
+static void keyring_free_object(void *object)
+{
+ key_put(keyring_ptr_to_key(object));
+}
+
+/*
+ * Operations for keyring management by the index-tree routines.
+ */
+static const struct assoc_array_ops keyring_assoc_array_ops = {
+ .get_key_chunk = keyring_get_key_chunk,
+ .get_object_key_chunk = keyring_get_object_key_chunk,
+ .compare_object = keyring_compare_object,
+ .diff_objects = keyring_diff_objects,
+ .free_object = keyring_free_object,
+};
+
+/*
+ * Clean up a keyring when it is destroyed. Unpublish its name if it had one
+ * and dispose of its data.
+ *
+ * The garbage collector detects the final key_put(), removes the keyring from
+ * the serial number tree and then does RCU synchronisation before coming here,
+ * so we shouldn't need to worry about code poking around here with the RCU
+ * readlock held by this time.
+ */
+static void keyring_destroy(struct key *keyring)
+{
+ if (keyring->description) {
+ write_lock(&keyring_name_lock);
+
+ if (keyring->name_link.next != NULL &&
+ !list_empty(&keyring->name_link))
+ list_del(&keyring->name_link);
+
+ write_unlock(&keyring_name_lock);
+ }
+
+ if (keyring->restrict_link) {
+ struct key_restriction *keyres = keyring->restrict_link;
+
+ key_put(keyres->key);
+ kfree(keyres);
+ }
+
+ assoc_array_destroy(&keyring->keys, &keyring_assoc_array_ops);
+}
+
+/*
+ * Describe a keyring for /proc.
+ */
+static void keyring_describe(const struct key *keyring, struct seq_file *m)
+{
+ if (keyring->description)
+ seq_puts(m, keyring->description);
+ else
+ seq_puts(m, "[anon]");
+
+ if (key_is_positive(keyring)) {
+ if (keyring->keys.nr_leaves_on_tree != 0)
+ seq_printf(m, ": %lu", keyring->keys.nr_leaves_on_tree);
+ else
+ seq_puts(m, ": empty");
+ }
+}
+
+struct keyring_read_iterator_context {
+ size_t buflen;
+ size_t count;
+ key_serial_t __user *buffer;
+};
+
+static int keyring_read_iterator(const void *object, void *data)
+{
+ struct keyring_read_iterator_context *ctx = data;
+ const struct key *key = keyring_ptr_to_key(object);
+
+ kenter("{%s,%d},,{%zu/%zu}",
+ key->type->name, key->serial, ctx->count, ctx->buflen);
+
+ if (ctx->count >= ctx->buflen)
+ return 1;
+
+ *ctx->buffer++ = key->serial;
+ ctx->count += sizeof(key->serial);
+ return 0;
+}
+
+/*
+ * Read a list of key IDs from the keyring's contents in binary form
+ *
+ * The keyring's semaphore is read-locked by the caller. This prevents someone
+ * from modifying it under us - which could cause us to read key IDs multiple
+ * times.
+ */
+static long keyring_read(const struct key *keyring,
+ char __user *buffer, size_t buflen)
+{
+ struct keyring_read_iterator_context ctx;
+ long ret;
+
+ kenter("{%d},,%zu", key_serial(keyring), buflen);
+
+ if (buflen & (sizeof(key_serial_t) - 1))
+ return -EINVAL;
+
+ /* Copy as many key IDs as fit into the buffer */
+ if (buffer && buflen) {
+ ctx.buffer = (key_serial_t __user *)buffer;
+ ctx.buflen = buflen;
+ ctx.count = 0;
+ ret = assoc_array_iterate(&keyring->keys,
+ keyring_read_iterator, &ctx);
+ if (ret < 0) {
+ kleave(" = %ld [iterate]", ret);
+ return ret;
+ }
+ }
+
+ /* Return the size of the buffer needed */
+ ret = keyring->keys.nr_leaves_on_tree * sizeof(key_serial_t);
+ if (ret <= buflen)
+ kleave("= %ld [ok]", ret);
+ else
+ kleave("= %ld [buffer too small]", ret);
+ return ret;
+}
+
+/*
+ * Allocate a keyring and link into the destination keyring.
+ */
+struct key *keyring_alloc(const char *description, kuid_t uid, kgid_t gid,
+ const struct cred *cred, key_perm_t perm,
+ unsigned long flags,
+ struct key_restriction *restrict_link,
+ struct key *dest)
+{
+ struct key *keyring;
+ int ret;
+
+ keyring = key_alloc(&key_type_keyring, description,
+ uid, gid, cred, perm, flags, restrict_link);
+ if (!IS_ERR(keyring)) {
+ ret = key_instantiate_and_link(keyring, NULL, 0, dest, NULL);
+ if (ret < 0) {
+ key_put(keyring);
+ keyring = ERR_PTR(ret);
+ }
+ }
+
+ return keyring;
+}
+EXPORT_SYMBOL(keyring_alloc);
+
+/**
+ * restrict_link_reject - Give -EPERM to restrict link
+ * @keyring: The keyring being added to.
+ * @type: The type of key being added.
+ * @payload: The payload of the key intended to be added.
+ * @data: Additional data for evaluating restriction.
+ *
+ * Reject the addition of any links to a keyring. It can be overridden by
+ * passing KEY_ALLOC_BYPASS_RESTRICTION to key_instantiate_and_link() when
+ * adding a key to a keyring.
+ *
+ * This is meant to be stored in a key_restriction structure which is passed
+ * in the restrict_link parameter to keyring_alloc().
+ */
+int restrict_link_reject(struct key *keyring,
+ const struct key_type *type,
+ const union key_payload *payload,
+ struct key *restriction_key)
+{
+ return -EPERM;
+}
+
+/*
+ * By default, we keys found by getting an exact match on their descriptions.
+ */
+bool key_default_cmp(const struct key *key,
+ const struct key_match_data *match_data)
+{
+ return strcmp(key->description, match_data->raw_data) == 0;
+}
+
+/*
+ * Iteration function to consider each key found.
+ */
+static int keyring_search_iterator(const void *object, void *iterator_data)
+{
+ struct keyring_search_context *ctx = iterator_data;
+ const struct key *key = keyring_ptr_to_key(object);
+ unsigned long kflags = READ_ONCE(key->flags);
+ short state = READ_ONCE(key->state);
+
+ kenter("{%d}", key->serial);
+
+ /* ignore keys not of this type */
+ if (key->type != ctx->index_key.type) {
+ kleave(" = 0 [!type]");
+ return 0;
+ }
+
+ /* skip invalidated, revoked and expired keys */
+ if (ctx->flags & KEYRING_SEARCH_DO_STATE_CHECK) {
+ time_t expiry = READ_ONCE(key->expiry);
+
+ if (kflags & ((1 << KEY_FLAG_INVALIDATED) |
+ (1 << KEY_FLAG_REVOKED))) {
+ ctx->result = ERR_PTR(-EKEYREVOKED);
+ kleave(" = %d [invrev]", ctx->skipped_ret);
+ goto skipped;
+ }
+
+ if (expiry && ctx->now.tv_sec >= expiry) {
+ if (!(ctx->flags & KEYRING_SEARCH_SKIP_EXPIRED))
+ ctx->result = ERR_PTR(-EKEYEXPIRED);
+ kleave(" = %d [expire]", ctx->skipped_ret);
+ goto skipped;
+ }
+ }
+
+ /* keys that don't match */
+ if (!ctx->match_data.cmp(key, &ctx->match_data)) {
+ kleave(" = 0 [!match]");
+ return 0;
+ }
+
+ /* key must have search permissions */
+ if (!(ctx->flags & KEYRING_SEARCH_NO_CHECK_PERM) &&
+ key_task_permission(make_key_ref(key, ctx->possessed),
+ ctx->cred, KEY_NEED_SEARCH) < 0) {
+ ctx->result = ERR_PTR(-EACCES);
+ kleave(" = %d [!perm]", ctx->skipped_ret);
+ goto skipped;
+ }
+
+ if (ctx->flags & KEYRING_SEARCH_DO_STATE_CHECK) {
+ /* we set a different error code if we pass a negative key */
+ if (state < 0) {
+ ctx->result = ERR_PTR(state);
+ kleave(" = %d [neg]", ctx->skipped_ret);
+ goto skipped;
+ }
+ }
+
+ /* Found */
+ ctx->result = make_key_ref(key, ctx->possessed);
+ kleave(" = 1 [found]");
+ return 1;
+
+skipped:
+ return ctx->skipped_ret;
+}
+
+/*
+ * Search inside a keyring for a key. We can search by walking to it
+ * directly based on its index-key or we can iterate over the entire
+ * tree looking for it, based on the match function.
+ */
+static int search_keyring(struct key *keyring, struct keyring_search_context *ctx)
+{
+ if (ctx->match_data.lookup_type == KEYRING_SEARCH_LOOKUP_DIRECT) {
+ const void *object;
+
+ object = assoc_array_find(&keyring->keys,
+ &keyring_assoc_array_ops,
+ &ctx->index_key);
+ return object ? ctx->iterator(object, ctx) : 0;
+ }
+ return assoc_array_iterate(&keyring->keys, ctx->iterator, ctx);
+}
+
+/*
+ * Search a tree of keyrings that point to other keyrings up to the maximum
+ * depth.
+ */
+static bool search_nested_keyrings(struct key *keyring,
+ struct keyring_search_context *ctx)
+{
+ struct {
+ struct key *keyring;
+ struct assoc_array_node *node;
+ int slot;
+ } stack[KEYRING_SEARCH_MAX_DEPTH];
+
+ struct assoc_array_shortcut *shortcut;
+ struct assoc_array_node *node;
+ struct assoc_array_ptr *ptr;
+ struct key *key;
+ int sp = 0, slot;
+
+ kenter("{%d},{%s,%s}",
+ keyring->serial,
+ ctx->index_key.type->name,
+ ctx->index_key.description);
+
+#define STATE_CHECKS (KEYRING_SEARCH_NO_STATE_CHECK | KEYRING_SEARCH_DO_STATE_CHECK)
+ BUG_ON((ctx->flags & STATE_CHECKS) == 0 ||
+ (ctx->flags & STATE_CHECKS) == STATE_CHECKS);
+
+ /* Check to see if this top-level keyring is what we are looking for
+ * and whether it is valid or not.
+ */
+ if (ctx->match_data.lookup_type == KEYRING_SEARCH_LOOKUP_ITERATE ||
+ keyring_compare_object(keyring, &ctx->index_key)) {
+ ctx->skipped_ret = 2;
+ switch (ctx->iterator(keyring_key_to_ptr(keyring), ctx)) {
+ case 1:
+ goto found;
+ case 2:
+ return false;
+ default:
+ break;
+ }
+ }
+
+ ctx->skipped_ret = 0;
+
+ /* Start processing a new keyring */
+descend_to_keyring:
+ kdebug("descend to %d", keyring->serial);
+ if (keyring->flags & ((1 << KEY_FLAG_INVALIDATED) |
+ (1 << KEY_FLAG_REVOKED)))
+ goto not_this_keyring;
+
+ /* Search through the keys in this keyring before its searching its
+ * subtrees.
+ */
+ if (search_keyring(keyring, ctx))
+ goto found;
+
+ /* Then manually iterate through the keyrings nested in this one.
+ *
+ * Start from the root node of the index tree. Because of the way the
+ * hash function has been set up, keyrings cluster on the leftmost
+ * branch of the root node (root slot 0) or in the root node itself.
+ * Non-keyrings avoid the leftmost branch of the root entirely (root
+ * slots 1-15).
+ */
+ ptr = READ_ONCE(keyring->keys.root);
+ if (!ptr)
+ goto not_this_keyring;
+
+ if (assoc_array_ptr_is_shortcut(ptr)) {
+ /* If the root is a shortcut, either the keyring only contains
+ * keyring pointers (everything clusters behind root slot 0) or
+ * doesn't contain any keyring pointers.
+ */
+ shortcut = assoc_array_ptr_to_shortcut(ptr);
+ smp_read_barrier_depends();
+ if ((shortcut->index_key[0] & ASSOC_ARRAY_FAN_MASK) != 0)
+ goto not_this_keyring;
+
+ ptr = READ_ONCE(shortcut->next_node);
+ node = assoc_array_ptr_to_node(ptr);
+ goto begin_node;
+ }
+
+ node = assoc_array_ptr_to_node(ptr);
+ smp_read_barrier_depends();
+
+ ptr = node->slots[0];
+ if (!assoc_array_ptr_is_meta(ptr))
+ goto begin_node;
+
+descend_to_node:
+ /* Descend to a more distal node in this keyring's content tree and go
+ * through that.
+ */
+ kdebug("descend");
+ if (assoc_array_ptr_is_shortcut(ptr)) {
+ shortcut = assoc_array_ptr_to_shortcut(ptr);
+ smp_read_barrier_depends();
+ ptr = READ_ONCE(shortcut->next_node);
+ BUG_ON(!assoc_array_ptr_is_node(ptr));
+ }
+ node = assoc_array_ptr_to_node(ptr);
+
+begin_node:
+ kdebug("begin_node");
+ smp_read_barrier_depends();
+ slot = 0;
+ascend_to_node:
+ /* Go through the slots in a node */
+ for (; slot < ASSOC_ARRAY_FAN_OUT; slot++) {
+ ptr = READ_ONCE(node->slots[slot]);
+
+ if (assoc_array_ptr_is_meta(ptr) && node->back_pointer)
+ goto descend_to_node;
+
+ if (!keyring_ptr_is_keyring(ptr))
+ continue;
+
+ key = keyring_ptr_to_key(ptr);
+
+ if (sp >= KEYRING_SEARCH_MAX_DEPTH) {
+ if (ctx->flags & KEYRING_SEARCH_DETECT_TOO_DEEP) {
+ ctx->result = ERR_PTR(-ELOOP);
+ return false;
+ }
+ goto not_this_keyring;
+ }
+
+ /* Search a nested keyring */
+ if (!(ctx->flags & KEYRING_SEARCH_NO_CHECK_PERM) &&
+ key_task_permission(make_key_ref(key, ctx->possessed),
+ ctx->cred, KEY_NEED_SEARCH) < 0)
+ continue;
+
+ /* stack the current position */
+ stack[sp].keyring = keyring;
+ stack[sp].node = node;
+ stack[sp].slot = slot;
+ sp++;
+
+ /* begin again with the new keyring */
+ keyring = key;
+ goto descend_to_keyring;
+ }
+
+ /* We've dealt with all the slots in the current node, so now we need
+ * to ascend to the parent and continue processing there.
+ */
+ ptr = READ_ONCE(node->back_pointer);
+ slot = node->parent_slot;
+
+ if (ptr && assoc_array_ptr_is_shortcut(ptr)) {
+ shortcut = assoc_array_ptr_to_shortcut(ptr);
+ smp_read_barrier_depends();
+ ptr = READ_ONCE(shortcut->back_pointer);
+ slot = shortcut->parent_slot;
+ }
+ if (!ptr)
+ goto not_this_keyring;
+ node = assoc_array_ptr_to_node(ptr);
+ smp_read_barrier_depends();
+ slot++;
+
+ /* If we've ascended to the root (zero backpointer), we must have just
+ * finished processing the leftmost branch rather than the root slots -
+ * so there can't be any more keyrings for us to find.
+ */
+ if (node->back_pointer) {
+ kdebug("ascend %d", slot);
+ goto ascend_to_node;
+ }
+
+ /* The keyring we're looking at was disqualified or didn't contain a
+ * matching key.
+ */
+not_this_keyring:
+ kdebug("not_this_keyring %d", sp);
+ if (sp <= 0) {
+ kleave(" = false");
+ return false;
+ }
+
+ /* Resume the processing of a keyring higher up in the tree */
+ sp--;
+ keyring = stack[sp].keyring;
+ node = stack[sp].node;
+ slot = stack[sp].slot + 1;
+ kdebug("ascend to %d [%d]", keyring->serial, slot);
+ goto ascend_to_node;
+
+ /* We found a viable match */
+found:
+ key = key_ref_to_ptr(ctx->result);
+ key_check(key);
+ if (!(ctx->flags & KEYRING_SEARCH_NO_UPDATE_TIME)) {
+ key->last_used_at = ctx->now.tv_sec;
+ keyring->last_used_at = ctx->now.tv_sec;
+ while (sp > 0)
+ stack[--sp].keyring->last_used_at = ctx->now.tv_sec;
+ }
+ kleave(" = true");
+ return true;
+}
+
+/**
+ * keyring_search_aux - Search a keyring tree for a key matching some criteria
+ * @keyring_ref: A pointer to the keyring with possession indicator.
+ * @ctx: The keyring search context.
+ *
+ * Search the supplied keyring tree for a key that matches the criteria given.
+ * The root keyring and any linked keyrings must grant Search permission to the
+ * caller to be searchable and keys can only be found if they too grant Search
+ * to the caller. The possession flag on the root keyring pointer controls use
+ * of the possessor bits in permissions checking of the entire tree. In
+ * addition, the LSM gets to forbid keyring searches and key matches.
+ *
+ * The search is performed as a breadth-then-depth search up to the prescribed
+ * limit (KEYRING_SEARCH_MAX_DEPTH).
+ *
+ * Keys are matched to the type provided and are then filtered by the match
+ * function, which is given the description to use in any way it sees fit. The
+ * match function may use any attributes of a key that it wishes to to
+ * determine the match. Normally the match function from the key type would be
+ * used.
+ *
+ * RCU can be used to prevent the keyring key lists from disappearing without
+ * the need to take lots of locks.
+ *
+ * Returns a pointer to the found key and increments the key usage count if
+ * successful; -EAGAIN if no matching keys were found, or if expired or revoked
+ * keys were found; -ENOKEY if only negative keys were found; -ENOTDIR if the
+ * specified keyring wasn't a keyring.
+ *
+ * In the case of a successful return, the possession attribute from
+ * @keyring_ref is propagated to the returned key reference.
+ */
+key_ref_t keyring_search_aux(key_ref_t keyring_ref,
+ struct keyring_search_context *ctx)
+{
+ struct key *keyring;
+ long err;
+
+ ctx->iterator = keyring_search_iterator;
+ ctx->possessed = is_key_possessed(keyring_ref);
+ ctx->result = ERR_PTR(-EAGAIN);
+
+ keyring = key_ref_to_ptr(keyring_ref);
+ key_check(keyring);
+
+ if (keyring->type != &key_type_keyring)
+ return ERR_PTR(-ENOTDIR);
+
+ if (!(ctx->flags & KEYRING_SEARCH_NO_CHECK_PERM)) {
+ err = key_task_permission(keyring_ref, ctx->cred, KEY_NEED_SEARCH);
+ if (err < 0)
+ return ERR_PTR(err);
+ }
+
+ rcu_read_lock();
+ ctx->now = current_kernel_time();
+ if (search_nested_keyrings(keyring, ctx))
+ __key_get(key_ref_to_ptr(ctx->result));
+ rcu_read_unlock();
+ return ctx->result;
+}
+
+/**
+ * keyring_search - Search the supplied keyring tree for a matching key
+ * @keyring: The root of the keyring tree to be searched.
+ * @type: The type of keyring we want to find.
+ * @description: The name of the keyring we want to find.
+ *
+ * As keyring_search_aux() above, but using the current task's credentials and
+ * type's default matching function and preferred search method.
+ */
+key_ref_t keyring_search(key_ref_t keyring,
+ struct key_type *type,
+ const char *description)
+{
+ struct keyring_search_context ctx = {
+ .index_key.type = type,
+ .index_key.description = description,
+ .index_key.desc_len = strlen(description),
+ .cred = current_cred(),
+ .match_data.cmp = key_default_cmp,
+ .match_data.raw_data = description,
+ .match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT,
+ .flags = KEYRING_SEARCH_DO_STATE_CHECK,
+ };
+ key_ref_t key;
+ int ret;
+
+ if (type->match_preparse) {
+ ret = type->match_preparse(&ctx.match_data);
+ if (ret < 0)
+ return ERR_PTR(ret);
+ }
+
+ key = keyring_search_aux(keyring, &ctx);
+
+ if (type->match_free)
+ type->match_free(&ctx.match_data);
+ return key;
+}
+EXPORT_SYMBOL(keyring_search);
+
+static struct key_restriction *keyring_restriction_alloc(
+ key_restrict_link_func_t check)
+{
+ struct key_restriction *keyres =
+ kzalloc(sizeof(struct key_restriction), GFP_KERNEL);
+
+ if (!keyres)
+ return ERR_PTR(-ENOMEM);
+
+ keyres->check = check;
+
+ return keyres;
+}
+
+/*
+ * Semaphore to serialise restriction setup to prevent reference count
+ * cycles through restriction key pointers.
+ */
+static DECLARE_RWSEM(keyring_serialise_restrict_sem);
+
+/*
+ * Check for restriction cycles that would prevent keyring garbage collection.
+ * keyring_serialise_restrict_sem must be held.
+ */
+static bool keyring_detect_restriction_cycle(const struct key *dest_keyring,
+ struct key_restriction *keyres)
+{
+ while (keyres && keyres->key &&
+ keyres->key->type == &key_type_keyring) {
+ if (keyres->key == dest_keyring)
+ return true;
+
+ keyres = keyres->key->restrict_link;
+ }
+
+ return false;
+}
+
+/**
+ * keyring_restrict - Look up and apply a restriction to a keyring
+ *
+ * @keyring: The keyring to be restricted
+ * @restriction: The restriction options to apply to the keyring
+ */
+int keyring_restrict(key_ref_t keyring_ref, const char *type,
+ const char *restriction)
+{
+ struct key *keyring;
+ struct key_type *restrict_type = NULL;
+ struct key_restriction *restrict_link;
+ int ret = 0;
+
+ keyring = key_ref_to_ptr(keyring_ref);
+ key_check(keyring);
+
+ if (keyring->type != &key_type_keyring)
+ return -ENOTDIR;
+
+ if (!type) {
+ restrict_link = keyring_restriction_alloc(restrict_link_reject);
+ } else {
+ restrict_type = key_type_lookup(type);
+
+ if (IS_ERR(restrict_type))
+ return PTR_ERR(restrict_type);
+
+ if (!restrict_type->lookup_restriction) {
+ ret = -ENOENT;
+ goto error;
+ }
+
+ restrict_link = restrict_type->lookup_restriction(restriction);
+ }
+
+ if (IS_ERR(restrict_link)) {
+ ret = PTR_ERR(restrict_link);
+ goto error;
+ }
+
+ down_write(&keyring->sem);
+ down_write(&keyring_serialise_restrict_sem);
+
+ if (keyring->restrict_link)
+ ret = -EEXIST;
+ else if (keyring_detect_restriction_cycle(keyring, restrict_link))
+ ret = -EDEADLK;
+ else
+ keyring->restrict_link = restrict_link;
+
+ up_write(&keyring_serialise_restrict_sem);
+ up_write(&keyring->sem);
+
+ if (ret < 0) {
+ key_put(restrict_link->key);
+ kfree(restrict_link);
+ }
+
+error:
+ if (restrict_type)
+ key_type_put(restrict_type);
+
+ return ret;
+}
+EXPORT_SYMBOL(keyring_restrict);
+
+/*
+ * Search the given keyring for a key that might be updated.
+ *
+ * The caller must guarantee that the keyring is a keyring and that the
+ * permission is granted to modify the keyring as no check is made here. The
+ * caller must also hold a lock on the keyring semaphore.
+ *
+ * Returns a pointer to the found key with usage count incremented if
+ * successful and returns NULL if not found. Revoked and invalidated keys are
+ * skipped over.
+ *
+ * If successful, the possession indicator is propagated from the keyring ref
+ * to the returned key reference.
+ */
+key_ref_t find_key_to_update(key_ref_t keyring_ref,
+ const struct keyring_index_key *index_key)
+{
+ struct key *keyring, *key;
+ const void *object;
+
+ keyring = key_ref_to_ptr(keyring_ref);
+
+ kenter("{%d},{%s,%s}",
+ keyring->serial, index_key->type->name, index_key->description);
+
+ object = assoc_array_find(&keyring->keys, &keyring_assoc_array_ops,
+ index_key);
+
+ if (object)
+ goto found;
+
+ kleave(" = NULL");
+ return NULL;
+
+found:
+ key = keyring_ptr_to_key(object);
+ if (key->flags & ((1 << KEY_FLAG_INVALIDATED) |
+ (1 << KEY_FLAG_REVOKED))) {
+ kleave(" = NULL [x]");
+ return NULL;
+ }
+ __key_get(key);
+ kleave(" = {%d}", key->serial);
+ return make_key_ref(key, is_key_possessed(keyring_ref));
+}
+
+/*
+ * Find a keyring with the specified name.
+ *
+ * Only keyrings that have nonzero refcount, are not revoked, and are owned by a
+ * user in the current user namespace are considered. If @uid_keyring is %true,
+ * the keyring additionally must have been allocated as a user or user session
+ * keyring; otherwise, it must grant Search permission directly to the caller.
+ *
+ * Returns a pointer to the keyring with the keyring's refcount having being
+ * incremented on success. -ENOKEY is returned if a key could not be found.
+ */
+struct key *find_keyring_by_name(const char *name, bool uid_keyring)
+{
+ struct key *keyring;
+ int bucket;
+
+ if (!name)
+ return ERR_PTR(-EINVAL);
+
+ bucket = keyring_hash(name);
+
+ read_lock(&keyring_name_lock);
+
+ if (keyring_name_hash[bucket].next) {
+ /* search this hash bucket for a keyring with a matching name
+ * that's readable and that hasn't been revoked */
+ list_for_each_entry(keyring,
+ &keyring_name_hash[bucket],
+ name_link
+ ) {
+ if (!kuid_has_mapping(current_user_ns(), keyring->user->uid))
+ continue;
+
+ if (test_bit(KEY_FLAG_REVOKED, &keyring->flags))
+ continue;
+
+ if (strcmp(keyring->description, name) != 0)
+ continue;
+
+ if (uid_keyring) {
+ if (!test_bit(KEY_FLAG_UID_KEYRING,
+ &keyring->flags))
+ continue;
+ } else {
+ if (key_permission(make_key_ref(keyring, 0),
+ KEY_NEED_SEARCH) < 0)
+ continue;
+ }
+
+ /* we've got a match but we might end up racing with
+ * key_cleanup() if the keyring is currently 'dead'
+ * (ie. it has a zero usage count) */
+ if (!refcount_inc_not_zero(&keyring->usage))
+ continue;
+ keyring->last_used_at = current_kernel_time().tv_sec;
+ goto out;
+ }
+ }
+
+ keyring = ERR_PTR(-ENOKEY);
+out:
+ read_unlock(&keyring_name_lock);
+ return keyring;
+}
+
+static int keyring_detect_cycle_iterator(const void *object,
+ void *iterator_data)
+{
+ struct keyring_search_context *ctx = iterator_data;
+ const struct key *key = keyring_ptr_to_key(object);
+
+ kenter("{%d}", key->serial);
+
+ /* We might get a keyring with matching index-key that is nonetheless a
+ * different keyring. */
+ if (key != ctx->match_data.raw_data)
+ return 0;
+
+ ctx->result = ERR_PTR(-EDEADLK);
+ return 1;
+}
+
+/*
+ * See if a cycle will will be created by inserting acyclic tree B in acyclic
+ * tree A at the topmost level (ie: as a direct child of A).
+ *
+ * Since we are adding B to A at the top level, checking for cycles should just
+ * be a matter of seeing if node A is somewhere in tree B.
+ */
+static int keyring_detect_cycle(struct key *A, struct key *B)
+{
+ struct keyring_search_context ctx = {
+ .index_key = A->index_key,
+ .match_data.raw_data = A,
+ .match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT,
+ .iterator = keyring_detect_cycle_iterator,
+ .flags = (KEYRING_SEARCH_NO_STATE_CHECK |
+ KEYRING_SEARCH_NO_UPDATE_TIME |
+ KEYRING_SEARCH_NO_CHECK_PERM |
+ KEYRING_SEARCH_DETECT_TOO_DEEP),
+ };
+
+ rcu_read_lock();
+ search_nested_keyrings(B, &ctx);
+ rcu_read_unlock();
+ return PTR_ERR(ctx.result) == -EAGAIN ? 0 : PTR_ERR(ctx.result);
+}
+
+/*
+ * Preallocate memory so that a key can be linked into to a keyring.
+ */
+int __key_link_begin(struct key *keyring,
+ const struct keyring_index_key *index_key,
+ struct assoc_array_edit **_edit)
+ __acquires(&keyring->sem)
+ __acquires(&keyring_serialise_link_sem)
+{
+ struct assoc_array_edit *edit;
+ int ret;
+
+ kenter("%d,%s,%s,",
+ keyring->serial, index_key->type->name, index_key->description);
+
+ BUG_ON(index_key->desc_len == 0);
+
+ if (keyring->type != &key_type_keyring)
+ return -ENOTDIR;
+
+ down_write(&keyring->sem);
+
+ ret = -EKEYREVOKED;
+ if (test_bit(KEY_FLAG_REVOKED, &keyring->flags))
+ goto error_krsem;
+
+ /* serialise link/link calls to prevent parallel calls causing a cycle
+ * when linking two keyring in opposite orders */
+ if (index_key->type == &key_type_keyring)
+ down_write(&keyring_serialise_link_sem);
+
+ /* Create an edit script that will insert/replace the key in the
+ * keyring tree.
+ */
+ edit = assoc_array_insert(&keyring->keys,
+ &keyring_assoc_array_ops,
+ index_key,
+ NULL);
+ if (IS_ERR(edit)) {
+ ret = PTR_ERR(edit);
+ goto error_sem;
+ }
+
+ /* If we're not replacing a link in-place then we're going to need some
+ * extra quota.
+ */
+ if (!edit->dead_leaf) {
+ ret = key_payload_reserve(keyring,
+ keyring->datalen + KEYQUOTA_LINK_BYTES);
+ if (ret < 0)
+ goto error_cancel;
+ }
+
+ *_edit = edit;
+ kleave(" = 0");
+ return 0;
+
+error_cancel:
+ assoc_array_cancel_edit(edit);
+error_sem:
+ if (index_key->type == &key_type_keyring)
+ up_write(&keyring_serialise_link_sem);
+error_krsem:
+ up_write(&keyring->sem);
+ kleave(" = %d", ret);
+ return ret;
+}
+
+/*
+ * Check already instantiated keys aren't going to be a problem.
+ *
+ * The caller must have called __key_link_begin(). Don't need to call this for
+ * keys that were created since __key_link_begin() was called.
+ */
+int __key_link_check_live_key(struct key *keyring, struct key *key)
+{
+ if (key->type == &key_type_keyring)
+ /* check that we aren't going to create a cycle by linking one
+ * keyring to another */
+ return keyring_detect_cycle(keyring, key);
+ return 0;
+}
+
+/*
+ * Link a key into to a keyring.
+ *
+ * Must be called with __key_link_begin() having being called. Discards any
+ * already extant link to matching key if there is one, so that each keyring
+ * holds at most one link to any given key of a particular type+description
+ * combination.
+ */
+void __key_link(struct key *key, struct assoc_array_edit **_edit)
+{
+ __key_get(key);
+ assoc_array_insert_set_object(*_edit, keyring_key_to_ptr(key));
+ assoc_array_apply_edit(*_edit);
+ *_edit = NULL;
+}
+
+/*
+ * Finish linking a key into to a keyring.
+ *
+ * Must be called with __key_link_begin() having being called.
+ */
+void __key_link_end(struct key *keyring,
+ const struct keyring_index_key *index_key,
+ struct assoc_array_edit *edit)
+ __releases(&keyring->sem)
+ __releases(&keyring_serialise_link_sem)
+{
+ BUG_ON(index_key->type == NULL);
+ kenter("%d,%s,", keyring->serial, index_key->type->name);
+
+ if (index_key->type == &key_type_keyring)
+ up_write(&keyring_serialise_link_sem);
+
+ if (edit) {
+ if (!edit->dead_leaf) {
+ key_payload_reserve(keyring,
+ keyring->datalen - KEYQUOTA_LINK_BYTES);
+ }
+ assoc_array_cancel_edit(edit);
+ }
+ up_write(&keyring->sem);
+}
+
+/*
+ * Check addition of keys to restricted keyrings.
+ */
+static int __key_link_check_restriction(struct key *keyring, struct key *key)
+{
+ if (!keyring->restrict_link || !keyring->restrict_link->check)
+ return 0;
+ return keyring->restrict_link->check(keyring, key->type, &key->payload,
+ keyring->restrict_link->key);
+}
+
+/**
+ * key_link - Link a key to a keyring
+ * @keyring: The keyring to make the link in.
+ * @key: The key to link to.
+ *
+ * Make a link in a keyring to a key, such that the keyring holds a reference
+ * on that key and the key can potentially be found by searching that keyring.
+ *
+ * This function will write-lock the keyring's semaphore and will consume some
+ * of the user's key data quota to hold the link.
+ *
+ * Returns 0 if successful, -ENOTDIR if the keyring isn't a keyring,
+ * -EKEYREVOKED if the keyring has been revoked, -ENFILE if the keyring is
+ * full, -EDQUOT if there is insufficient key data quota remaining to add
+ * another link or -ENOMEM if there's insufficient memory.
+ *
+ * It is assumed that the caller has checked that it is permitted for a link to
+ * be made (the keyring should have Write permission and the key Link
+ * permission).
+ */
+int key_link(struct key *keyring, struct key *key)
+{
+ struct assoc_array_edit *edit;
+ int ret;
+
+ kenter("{%d,%d}", keyring->serial, refcount_read(&keyring->usage));
+
+ key_check(keyring);
+ key_check(key);
+
+ ret = __key_link_begin(keyring, &key->index_key, &edit);
+ if (ret == 0) {
+ kdebug("begun {%d,%d}", keyring->serial, refcount_read(&keyring->usage));
+ ret = __key_link_check_restriction(keyring, key);
+ if (ret == 0)
+ ret = __key_link_check_live_key(keyring, key);
+ if (ret == 0)
+ __key_link(key, &edit);
+ __key_link_end(keyring, &key->index_key, edit);
+ }
+
+ kleave(" = %d {%d,%d}", ret, keyring->serial, refcount_read(&keyring->usage));
+ return ret;
+}
+EXPORT_SYMBOL(key_link);
+
+/**
+ * key_unlink - Unlink the first link to a key from a keyring.
+ * @keyring: The keyring to remove the link from.
+ * @key: The key the link is to.
+ *
+ * Remove a link from a keyring to a key.
+ *
+ * This function will write-lock the keyring's semaphore.
+ *
+ * Returns 0 if successful, -ENOTDIR if the keyring isn't a keyring, -ENOENT if
+ * the key isn't linked to by the keyring or -ENOMEM if there's insufficient
+ * memory.
+ *
+ * It is assumed that the caller has checked that it is permitted for a link to
+ * be removed (the keyring should have Write permission; no permissions are
+ * required on the key).
+ */
+int key_unlink(struct key *keyring, struct key *key)
+{
+ struct assoc_array_edit *edit;
+ int ret;
+
+ key_check(keyring);
+ key_check(key);
+
+ if (keyring->type != &key_type_keyring)
+ return -ENOTDIR;
+
+ down_write(&keyring->sem);
+
+ edit = assoc_array_delete(&keyring->keys, &keyring_assoc_array_ops,
+ &key->index_key);
+ if (IS_ERR(edit)) {
+ ret = PTR_ERR(edit);
+ goto error;
+ }
+ ret = -ENOENT;
+ if (edit == NULL)
+ goto error;
+
+ assoc_array_apply_edit(edit);
+ key_payload_reserve(keyring, keyring->datalen - KEYQUOTA_LINK_BYTES);
+ ret = 0;
+
+error:
+ up_write(&keyring->sem);
+ return ret;
+}
+EXPORT_SYMBOL(key_unlink);
+
+/**
+ * keyring_clear - Clear a keyring
+ * @keyring: The keyring to clear.
+ *
+ * Clear the contents of the specified keyring.
+ *
+ * Returns 0 if successful or -ENOTDIR if the keyring isn't a keyring.
+ */
+int keyring_clear(struct key *keyring)
+{
+ struct assoc_array_edit *edit;
+ int ret;
+
+ if (keyring->type != &key_type_keyring)
+ return -ENOTDIR;
+
+ down_write(&keyring->sem);
+
+ edit = assoc_array_clear(&keyring->keys, &keyring_assoc_array_ops);
+ if (IS_ERR(edit)) {
+ ret = PTR_ERR(edit);
+ } else {
+ if (edit)
+ assoc_array_apply_edit(edit);
+ key_payload_reserve(keyring, 0);
+ ret = 0;
+ }
+
+ up_write(&keyring->sem);
+ return ret;
+}
+EXPORT_SYMBOL(keyring_clear);
+
+/*
+ * Dispose of the links from a revoked keyring.
+ *
+ * This is called with the key sem write-locked.
+ */
+static void keyring_revoke(struct key *keyring)
+{
+ struct assoc_array_edit *edit;
+
+ edit = assoc_array_clear(&keyring->keys, &keyring_assoc_array_ops);
+ if (!IS_ERR(edit)) {
+ if (edit)
+ assoc_array_apply_edit(edit);
+ key_payload_reserve(keyring, 0);
+ }
+}
+
+static bool keyring_gc_select_iterator(void *object, void *iterator_data)
+{
+ struct key *key = keyring_ptr_to_key(object);
+ time_t *limit = iterator_data;
+
+ if (key_is_dead(key, *limit))
+ return false;
+ key_get(key);
+ return true;
+}
+
+static int keyring_gc_check_iterator(const void *object, void *iterator_data)
+{
+ const struct key *key = keyring_ptr_to_key(object);
+ time_t *limit = iterator_data;
+
+ key_check(key);
+ return key_is_dead(key, *limit);
+}
+
+/*
+ * Garbage collect pointers from a keyring.
+ *
+ * Not called with any locks held. The keyring's key struct will not be
+ * deallocated under us as only our caller may deallocate it.
+ */
+void keyring_gc(struct key *keyring, time_t limit)
+{
+ int result;
+
+ kenter("%x{%s}", keyring->serial, keyring->description ?: "");
+
+ if (keyring->flags & ((1 << KEY_FLAG_INVALIDATED) |
+ (1 << KEY_FLAG_REVOKED)))
+ goto dont_gc;
+
+ /* scan the keyring looking for dead keys */
+ rcu_read_lock();
+ result = assoc_array_iterate(&keyring->keys,
+ keyring_gc_check_iterator, &limit);
+ rcu_read_unlock();
+ if (result == true)
+ goto do_gc;
+
+dont_gc:
+ kleave(" [no gc]");
+ return;
+
+do_gc:
+ down_write(&keyring->sem);
+ assoc_array_gc(&keyring->keys, &keyring_assoc_array_ops,
+ keyring_gc_select_iterator, &limit);
+ up_write(&keyring->sem);
+ kleave(" [gc]");
+}
+
+/*
+ * Garbage collect restriction pointers from a keyring.
+ *
+ * Keyring restrictions are associated with a key type, and must be cleaned
+ * up if the key type is unregistered. The restriction is altered to always
+ * reject additional keys so a keyring cannot be opened up by unregistering
+ * a key type.
+ *
+ * Not called with any keyring locks held. The keyring's key struct will not
+ * be deallocated under us as only our caller may deallocate it.
+ *
+ * The caller is required to hold key_types_sem and dead_type->sem. This is
+ * fulfilled by key_gc_keytype() holding the locks on behalf of
+ * key_garbage_collector(), which it invokes on a workqueue.
+ */
+void keyring_restriction_gc(struct key *keyring, struct key_type *dead_type)
+{
+ struct key_restriction *keyres;
+
+ kenter("%x{%s}", keyring->serial, keyring->description ?: "");
+
+ /*
+ * keyring->restrict_link is only assigned at key allocation time
+ * or with the key type locked, so the only values that could be
+ * concurrently assigned to keyring->restrict_link are for key
+ * types other than dead_type. Given this, it's ok to check
+ * the key type before acquiring keyring->sem.
+ */
+ if (!dead_type || !keyring->restrict_link ||
+ keyring->restrict_link->keytype != dead_type) {
+ kleave(" [no restriction gc]");
+ return;
+ }
+
+ /* Lock the keyring to ensure that a link is not in progress */
+ down_write(&keyring->sem);
+
+ keyres = keyring->restrict_link;
+
+ keyres->check = restrict_link_reject;
+
+ key_put(keyres->key);
+ keyres->key = NULL;
+ keyres->keytype = NULL;
+
+ up_write(&keyring->sem);
+
+ kleave(" [restriction gc]");
+}