// SPDX-License-Identifier: GPL-2.0-or-later/* Keyring handling * * Copyright (C) 2004-2005, 2008, 2013 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) */ #include <linux/export.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 <linux/user_namespace.h>#include <linux/nsproxy.h>#include <keys/keyring-type.h>#include <keys/user-type.h>#include <linux/assoc_array_priv.h>#include <linux/uaccess.h>#include <net/net_namespace.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 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 DEFINE_RWLOCK(keyring_name_lock); /* * Clean up the bits of user_namespace that belong to us. */void key_free_user_ns(struct user_namespace *ns){ write_lock(&keyring_name_lock); list_del_init(&ns->keyring_name_list); write_unlock(&keyring_name_lock); key_put(ns->user_keyring_register);#ifdef CONFIG_PERSISTENT_KEYRINGS key_put(ns->persistent_keyring_register);#endif} /* * 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 *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 DEFINE_MUTEX(keyring_serialise_link_lock); /* * Publish the name of a keyring so that it can be found by name (if it has * one and it doesn't begin with a dot). */static void keyring_publish_name(struct key *keyring){ struct user_namespace *ns = current_user_ns(); if (keyring->description && keyring->description[0] && keyring->description[0] != '.') { write_lock(&keyring_name_lock); list_add_tail(&keyring->name_link, &ns->keyring_name_list); 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 void hash_key_type_and_desc(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); piece = (unsigned long)index_key->domain_tag; acc = mult_64x32_and_fold(acc, piece); 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) hash |= (hash >> (ASSOC_ARRAY_KEY_CHUNK_SIZE - level_shift)) | 1; else if (index_key->type == &key_type_keyring && (hash & fan_mask) != 0) hash = (hash + (hash << level_shift)) & ~fan_mask; index_key->hash = hash;} /* * Finalise an index key to include a part of the description actually in the * index key, to set the domain tag and to calculate the hash. */void key_set_index_key(struct keyring_index_key *index_key){ static struct key_tag default_domain_tag = { .usage = REFCOUNT_INIT(1), }; size_t n = min_t(size_t, index_key->desc_len, sizeof(index_key->desc)); memcpy(index_key->desc, index_key->description, n); if (!index_key->domain_tag) { if (index_key->type->flags & KEY_TYPE_NET_DOMAIN) index_key->domain_tag = current->nsproxy->net_ns->key_domain; else index_key->domain_tag = &default_domain_tag; } hash_key_type_and_desc(index_key);} /** * key_put_tag - Release a ref on a tag. * @tag: The tag to release. * * This releases a reference the given tag and returns true if that ref was the * last one. */bool key_put_tag(struct key_tag *tag){ if (refcount_dec_and_test(&tag->usage)) { kfree_rcu(tag, rcu); return true; } return false;} /** * key_remove_domain - Kill off a key domain and gc its keys * @domain_tag: The domain tag to release. * * This marks a domain tag as being dead and releases a ref on it. If that * wasn't the last reference, the garbage collector is poked to try and delete * all keys that were in the domain. */void key_remove_domain(struct key_tag *domain_tag){ domain_tag->removed = true; if (!key_put_tag(domain_tag)) key_schedule_gc_links();} /* * Build the next index key chunk. * * 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; const u8 *d; int desc_len = index_key->desc_len, n = sizeof(chunk); unsigned int offset; level /= ASSOC_ARRAY_KEY_CHUNK_SIZE; switch (level) { case 0: return index_key->hash; case 1: return index_key->x; case 2: return (unsigned long)index_key->type; case 3: return (unsigned long)index_key->domain_tag; default: level -= 4; offset = sizeof(index_key->desc) + level * sizeof(long); if (desc_len <= offset) return 0; d = index_key->description + offset; desc_len -= offset; if (desc_len > n) desc_len = n; d += desc_len; do { chunk <<= 8; chunk |= *--d; } while (--desc_len > 0); 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.domain_tag == index_key->domain_tag && 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 = a->hash; seg_b = b->hash; if ((seg_a ^ seg_b) != 0) goto differ; level += ASSOC_ARRAY_KEY_CHUNK_SIZE / 8; /* 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. */ seg_a = a->x; seg_b = b->x; if ((seg_a ^ seg_b) != 0) goto differ; level += sizeof(unsigned long); /* The next bit may not work on big endian */ seg_a = (unsigned long)a->type; seg_b = (unsigned long)b->type; if ((seg_a ^ seg_b) != 0) goto differ; level += sizeof(unsigned long); seg_a = (unsigned long)a->domain_tag; seg_b = (unsigned long)b->domain_tag; if ((seg_a ^ seg_b) != 0) goto differ; level += sizeof(unsigned long); i = sizeof(a->desc); if (a->desc_len <= i) goto same; 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 - (int)sizeof(a->desc);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 *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 *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 *)buffer; ctx.buflen = buflen; ctx.count = 0; ret = assoc_array_iterate(&keyring->keys, keyring_read_iterator, &ctx);Lines 1–500 of 1800. Load more
// SPDX-License-Identifier: GPL-2.0-or-later /* Keyring handling * * Copyright (C) 2004-2005, 2008, 2013 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) */ #include <linux/export.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 <linux/user_namespace.h> #include <linux/nsproxy.h> #include <keys/keyring-type.h> #include <keys/user-type.h> #include <linux/assoc_array_priv.h> #include <linux/uaccess.h> #include <net/net_namespace.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 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 DEFINE_RWLOCK(keyring_name_lock); /* * Clean up the bits of user_namespace that belong to us. */ void key_free_user_ns(struct user_namespace *ns) { write_lock(&keyring_name_lock); list_del_init(&ns->keyring_name_list); write_unlock(&keyring_name_lock); key_put(ns->user_keyring_register); #ifdef CONFIG_PERSISTENT_KEYRINGS key_put(ns->persistent_keyring_register); #endif } /* * 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 *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 DEFINE_MUTEX(keyring_serialise_link_lock); /* * Publish the name of a keyring so that it can be found by name (if it has * one and it doesn't begin with a dot). */ static void keyring_publish_name(struct key *keyring) { struct user_namespace *ns = current_user_ns(); if (keyring->description && keyring->description[0] && keyring->description[0] != '.') { write_lock(&keyring_name_lock); list_add_tail(&keyring->name_link, &ns->keyring_name_list); 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 void hash_key_type_and_desc(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); piece = (unsigned long)index_key->domain_tag; acc = mult_64x32_and_fold(acc, piece); 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) hash |= (hash >> (ASSOC_ARRAY_KEY_CHUNK_SIZE - level_shift)) | 1; else if (index_key->type == &key_type_keyring && (hash & fan_mask) != 0) hash = (hash + (hash << level_shift)) & ~fan_mask; index_key->hash = hash; } /* * Finalise an index key to include a part of the description actually in the * index key, to set the domain tag and to calculate the hash. */ void key_set_index_key(struct keyring_index_key *index_key) { static struct key_tag default_domain_tag = { .usage = REFCOUNT_INIT(1), }; size_t n = min_t(size_t, index_key->desc_len, sizeof(index_key->desc)); memcpy(index_key->desc, index_key->description, n); if (!index_key->domain_tag) { if (index_key->type->flags & KEY_TYPE_NET_DOMAIN) index_key->domain_tag = current->nsproxy->net_ns->key_domain; else index_key->domain_tag = &default_domain_tag; } hash_key_type_and_desc(index_key); } /** * key_put_tag - Release a ref on a tag. * @tag: The tag to release. * * This releases a reference the given tag and returns true if that ref was the * last one. */ bool key_put_tag(struct key_tag *tag) { if (refcount_dec_and_test(&tag->usage)) { kfree_rcu(tag, rcu); return true; } return false; } /** * key_remove_domain - Kill off a key domain and gc its keys * @domain_tag: The domain tag to release. * * This marks a domain tag as being dead and releases a ref on it. If that * wasn't the last reference, the garbage collector is poked to try and delete * all keys that were in the domain. */ void key_remove_domain(struct key_tag *domain_tag) { domain_tag->removed = true; if (!key_put_tag(domain_tag)) key_schedule_gc_links(); } /* * Build the next index key chunk. * * 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; const u8 *d; int desc_len = index_key->desc_len, n = sizeof(chunk); unsigned int offset; level /= ASSOC_ARRAY_KEY_CHUNK_SIZE; switch (level) { case 0: return index_key->hash; case 1: return index_key->x; case 2: return (unsigned long)index_key->type; case 3: return (unsigned long)index_key->domain_tag; default: level -= 4; offset = sizeof(index_key->desc) + level * sizeof(long); if (desc_len <= offset) return 0; d = index_key->description + offset; desc_len -= offset; if (desc_len > n) desc_len = n; d += desc_len; do { chunk <<= 8; chunk |= *--d; } while (--desc_len > 0); 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.domain_tag == index_key->domain_tag && 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 = a->hash; seg_b = b->hash; if ((seg_a ^ seg_b) != 0) goto differ; level += ASSOC_ARRAY_KEY_CHUNK_SIZE / 8; /* 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. */ seg_a = a->x; seg_b = b->x; if ((seg_a ^ seg_b) != 0) goto differ; level += sizeof(unsigned long); /* The next bit may not work on big endian */ seg_a = (unsigned long)a->type; seg_b = (unsigned long)b->type; if ((seg_a ^ seg_b) != 0) goto differ; level += sizeof(unsigned long); seg_a = (unsigned long)a->domain_tag; seg_b = (unsigned long)b->domain_tag; if ((seg_a ^ seg_b) != 0) goto differ; level += sizeof(unsigned long); i = sizeof(a->desc); if (a->desc_len <= i) goto same; 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 - (int)sizeof(a->desc); 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 *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 *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 *)buffer; ctx.buflen = buflen; ctx.count = 0; ret = assoc_array_iterate(&keyring->keys, keyring_read_iterator, &ctx);