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Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells To: keyrings@vger.kernel.org cc: dhowells@redhat.com, Jarkko Sakkinen , linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] keys: Add tracepoints for the keyrings facility Precedence: bulk X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-ID: <2014450.1721690435.1@warthog.procyon.org.uk> Date: Tue, 23 Jul 2024 00:20:35 +0100 Message-ID: <2014451.1721690435@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 3.0 on 10.30.177.40 Add some tracepoints to aid in debuggin the keyrings facility and applications that use it. A number of events and operations are traceable, including: - Allocation - Refcounting - Instantiation and negative instantiation/rejection - Update - Detection of key being dead - Key quota changes - Key quota failure - Link, unlink and move - Keyring clearance - Revocation and invalidation - Garbage collection Signed-off-by: David Howells cc: Jarkko Sakkinen cc: keyrings@vger.kernel.org cc: linux-security-module@vger.kernel.org --- Documentation/security/keys/core.rst | 1 crypto/asymmetric_keys/restrict.c | 6 include/keys/key_user.h | 35 +++ include/linux/key.h | 16 - include/trace/events/key.h | 401 +++++++++++++++++++++++++++++++++++ security/keys/gc.c | 4 security/keys/internal.h | 41 --- security/keys/key.c | 66 +++++ security/keys/keyctl.c | 2 security/keys/keyring.c | 45 +++ security/keys/process_keys.c | 15 - 11 files changed, 562 insertions(+), 70 deletions(-) diff --git a/Documentation/security/keys/core.rst b/Documentation/security/keys/core.rst index 326b8a973828..0b179540d885 100644 --- a/Documentation/security/keys/core.rst +++ b/Documentation/security/keys/core.rst @@ -1217,7 +1217,6 @@ payload contents" for more information. * Extra references can be made to a key by calling one of the following functions:: - struct key *__key_get(struct key *key); struct key *key_get(struct key *key); Keys so references will need to be disposed of by calling key_put() when diff --git a/crypto/asymmetric_keys/restrict.c b/crypto/asymmetric_keys/restrict.c index afcd4d101ac5..1ea7bfd4e5d7 100644 --- a/crypto/asymmetric_keys/restrict.c +++ b/crypto/asymmetric_keys/restrict.c @@ -267,20 +267,20 @@ static int key_or_keyring_common(struct key *dest_keyring, if (!sig->auth_ids[0] && !sig->auth_ids[1]) { if (asymmetric_key_id_same(signer_ids[2], sig->auth_ids[2])) - key = __key_get(trusted); + key = key_get(trusted); } else if (!sig->auth_ids[0] || !sig->auth_ids[1]) { const struct asymmetric_key_id *auth_id; auth_id = sig->auth_ids[0] ?: sig->auth_ids[1]; if (match_either_id(signer_ids, auth_id)) - key = __key_get(trusted); + key = key_get(trusted); } else if (asymmetric_key_id_same(signer_ids[1], sig->auth_ids[1]) && match_either_id(signer_ids, sig->auth_ids[0])) { - key = __key_get(trusted); + key = key_get(trusted); } } else { return -EOPNOTSUPP; diff --git a/include/keys/key_user.h b/include/keys/key_user.h new file mode 100644 index 000000000000..e9c383d8116e --- /dev/null +++ b/include/keys/key_user.h @@ -0,0 +1,35 @@ +/* User quota tracking for keys. + * + * Copyright (C) 2024 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 Licence + * as published by the Free Software Foundation; either version + * 2 of the Licence, or (at your option) any later version. + */ + +#ifndef _KEYS_KEY_USER_H +#define _KEYS_KEY_USER_H + +/* + * Keep track of keys for a user. + * + * This needs to be separate to user_struct to avoid a refcount-loop + * (user_struct pins some keyrings which pin this struct). + * + * We also keep track of keys under request from userspace for this UID here. + */ +struct key_user { + struct rb_node node; + struct mutex cons_lock; /* construction initiation lock */ + spinlock_t lock; + refcount_t usage; /* for accessing qnkeys & qnbytes */ + atomic_t nkeys; /* number of keys */ + atomic_t nikeys; /* number of instantiated keys */ + kuid_t uid; + int qnkeys; /* number of keys allocated to this user */ + int qnbytes; /* number of bytes allocated to this user */ +}; + +#endif /* _KEYS_KEY_USER_H */ diff --git a/include/linux/key.h b/include/linux/key.h index 943a432da3ae..4e5baf3e7286 100644 --- a/include/linux/key.h +++ b/include/linux/key.h @@ -299,24 +299,20 @@ extern struct key *key_alloc(struct key_type *type, extern void key_revoke(struct key *key); extern void key_invalidate(struct key *key); +struct key *key_get(struct key *key); +struct key *key_try_get(struct key *key); extern void key_put(struct key *key); extern bool key_put_tag(struct key_tag *tag); extern void key_remove_domain(struct key_tag *domain_tag); -static inline struct key *__key_get(struct key *key) -{ - refcount_inc(&key->usage); - return key; -} - -static inline struct key *key_get(struct key *key) +static inline void key_ref_put(key_ref_t key_ref) { - return key ? __key_get(key) : key; + key_put(key_ref_to_ptr(key_ref)); } -static inline void key_ref_put(key_ref_t key_ref) +static inline void key_ref_get(key_ref_t key_ref) { - key_put(key_ref_to_ptr(key_ref)); + key_get(key_ref_to_ptr(key_ref)); } extern struct key *request_key_tag(struct key_type *type, diff --git a/include/trace/events/key.h b/include/trace/events/key.h new file mode 100644 index 000000000000..b3f8c39cc0e8 --- /dev/null +++ b/include/trace/events/key.h @@ -0,0 +1,401 @@ +/* Keyrings tracepoints + * + * Copyright (C) 2024 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 Licence + * as published by the Free Software Foundation; either version + * 2 of the Licence, or (at your option) any later version. + */ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM key + +#if !defined(_TRACE_KEY_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_KEY_H + +#include + +struct key; + +/* + * Declare tracing information enums and their string mappings for display. + */ +#define key_ref_traces \ + EM(key_trace_ref_alloc, "ALLOC") \ + EM(key_trace_ref_free, "FREE ") \ + EM(key_trace_ref_gc, "GC ") \ + EM(key_trace_ref_get, "GET ") \ + EM(key_trace_ref_put, "PUT ") \ + E_(key_trace_ref_try_get, "GET ") + +#define key_dead_traces \ + EM(key_trace_dead_type_removed, "TYPR") \ + EM(key_trace_dead_domain_removed, "DOMR") \ + EM(key_trace_dead_expired, "EXPD") \ + E_(key_trace_dead_invalidated, "INVL") + +/* + * Generate enums for tracing information. + */ +#ifndef __NETFS_DECLARE_TRACE_ENUMS_ONCE_ONLY +#define __NETFS_DECLARE_TRACE_ENUMS_ONCE_ONLY + +#undef EM +#undef E_ +#define EM(a, b) a, +#define E_(a, b) a + +enum key_dead_trace { key_dead_traces } __mode(byte); +enum key_ref_trace { key_ref_traces } __mode(byte); + +#endif /* end __RXRPC_DECLARE_TRACE_ENUMS_ONCE_ONLY */ + +/* + * Export enum symbols via userspace. + */ +#undef EM +#undef E_ +#define EM(a, b) TRACE_DEFINE_ENUM(a); +#define E_(a, b) TRACE_DEFINE_ENUM(a); + +key_dead_traces; +key_ref_traces; + +/* + * Now redefine the EM() and E_() macros to map the enums to the strings that + * will be printed in the output. + */ +#undef EM +#undef E_ +#define EM(a, b) { a, b }, +#define E_(a, b) { a, b } + +TRACE_EVENT(key_alloc, + TP_PROTO(const struct key *key), + + TP_ARGS(key), + + TP_STRUCT__entry( + __field(key_serial_t, key) + __field(uid_t, uid) + __array(char, type, 8) + __array(char, desc, 24) + ), + + TP_fast_assign( + __entry->key = key->serial; + __entry->uid = from_kuid(&init_user_ns, key->uid); + strncpy(__entry->type, key->type->name, sizeof(__entry->type) - 1); + strncpy(__entry->desc, key->description ?: "", sizeof(__entry->desc) - 1); + __entry->type[sizeof(__entry->type) - 1] = 0; + __entry->desc[sizeof(__entry->desc) - 1] = 0; + ), + + TP_printk("key=%08x uid=%08x t=%s d=%s", + __entry->key, + __entry->uid, + __entry->type, + __entry->desc) + ); + +TRACE_EVENT(key_ref, + TP_PROTO(key_serial_t key, unsigned int ref, enum key_ref_trace trace, + const void *where), + + TP_ARGS(key, ref, trace, where), + + TP_STRUCT__entry( + __field(key_serial_t, key) + __field(enum key_ref_trace, trace) + __field(unsigned int, ref) + __field(const void *, where) + ), + + TP_fast_assign( + __entry->key = key; + __entry->trace = trace; + __entry->ref = ref; + __entry->where = where; + ), + + TP_printk("key=%08x %s r=%d pc=%pSR", + __entry->key, + __print_symbolic(__entry->trace, key_ref_traces), + __entry->ref, + __entry->where) + ); + +TRACE_EVENT(key_instantiate, + TP_PROTO(const struct key *key, const struct key_preparsed_payload *prep), + + TP_ARGS(key, prep), + + TP_STRUCT__entry( + __field(key_serial_t, key) + __field(unsigned int, datalen) + __field(unsigned int, quotalen) + ), + + TP_fast_assign( + __entry->key = key->serial; + __entry->datalen = prep->datalen; + __entry->quotalen = prep->quotalen; + ), + + TP_printk("key=%08x dlen=%u qlen=%u", + __entry->key, + __entry->datalen, + __entry->quotalen) + ); + +TRACE_EVENT(key_reject, + TP_PROTO(const struct key *key, int error), + + TP_ARGS(key, error), + + TP_STRUCT__entry( + __field(key_serial_t, key) + __field(int, error) + ), + + TP_fast_assign( + __entry->key = key->serial; + __entry->error = error; + ), + + TP_printk("key=%08x err=%d", + __entry->key, + __entry->error) + ); + +TRACE_EVENT(key_update, + TP_PROTO(const struct key *key, const struct key_preparsed_payload *prep), + + TP_ARGS(key, prep), + + TP_STRUCT__entry( + __field(key_serial_t, key) + __field(unsigned int, datalen) + __field(unsigned int, quotalen) + ), + + TP_fast_assign( + __entry->key = key->serial; + __entry->datalen = prep->datalen; + __entry->quotalen = prep->quotalen; + ), + + TP_printk("key=%08x dlen=%u qlen=%u", + __entry->key, + __entry->datalen, + __entry->quotalen) + ); + +TRACE_EVENT(key_dead, + TP_PROTO(const struct key *key, enum key_dead_trace trace), + + TP_ARGS(key, trace), + + TP_STRUCT__entry( + __field(key_serial_t, key) + __field(enum key_dead_trace, trace) + ), + + TP_fast_assign( + __entry->key = key->serial; + __entry->trace = trace; + ), + + TP_printk("key=%08x %s", + __entry->key, + __print_symbolic(__entry->trace, key_dead_traces)) + ); + +TRACE_EVENT(key_quota, + TP_PROTO(const struct key_user *user, int change_keys, int change_bytes), + + TP_ARGS(user, change_keys, change_bytes), + + TP_STRUCT__entry( + __field(uid_t, uid) + __field(unsigned int, nkeys) + __field(unsigned int, nikeys) + __field(unsigned int, qnkeys) + __field(unsigned int, qnbytes) + __field(int, change_keys) + __field(int, change_bytes) + ), + + TP_fast_assign( + __entry->uid = from_kuid(&init_user_ns, user->uid); + __entry->nkeys = atomic_read(&user->nkeys); + __entry->nikeys = atomic_read(&user->nikeys); + __entry->qnkeys = user->qnkeys; + __entry->qnbytes = user->qnbytes; + __entry->change_keys = change_keys; + __entry->change_bytes = change_bytes; + ), + + TP_printk("uid=%d nkeys=%u/%u qkeys=%u qpay=%u ckeys=%d cpay=%d", + __entry->uid, + __entry->nikeys, __entry->nkeys, + __entry->qnkeys, + __entry->qnbytes, + __entry->change_keys, __entry->change_bytes) + ); + +TRACE_EVENT(key_edquot, + TP_PROTO(const struct key_user *user, unsigned int maxkeys, + unsigned int maxbytes, unsigned int reqbytes), + + TP_ARGS(user, maxkeys, maxbytes, reqbytes), + + TP_STRUCT__entry( + __field(uid_t, uid) + __field(unsigned int, nkeys) + __field(unsigned int, nikeys) + __field(unsigned int, qnkeys) + __field(unsigned int, qnbytes) + __field(unsigned int, maxkeys) + __field(unsigned int, maxbytes) + __field(unsigned int, reqbytes) + ), + + TP_fast_assign( + __entry->uid = from_kuid(&init_user_ns, user->uid); + __entry->nkeys = atomic_read(&user->nkeys); + __entry->nikeys = atomic_read(&user->nikeys); + __entry->qnkeys = user->qnkeys; + __entry->qnbytes = user->qnbytes; + __entry->maxkeys = maxkeys; + __entry->maxbytes = maxbytes; + __entry->reqbytes = reqbytes; + ), + + TP_printk("u=%d nkeys=%u/%u qkeys=%u/%u qpay=%u/%u cpay=%u", + __entry->uid, + __entry->nikeys, __entry->nkeys, + __entry->qnkeys, __entry->maxkeys, + __entry->qnbytes, __entry->maxbytes, + __entry->reqbytes) + ); + +TRACE_EVENT(key_link, + TP_PROTO(const struct key *keyring, const struct key *key), + + TP_ARGS(keyring, key), + + TP_STRUCT__entry( + __field(key_serial_t, keyring) + __field(key_serial_t, key) + ), + + TP_fast_assign( + __entry->keyring = keyring->serial; + __entry->key = key->serial; + ), + + TP_printk("key=%08x to=%08x", + __entry->key, __entry->keyring) + ); + +TRACE_EVENT(key_unlink, + TP_PROTO(const struct key *keyring, const struct key *key), + + TP_ARGS(keyring, key), + + TP_STRUCT__entry( + __field(key_serial_t, keyring) + __field(key_serial_t, key) + ), + + TP_fast_assign( + __entry->keyring = keyring->serial; + __entry->key = key->serial; + ), + + TP_printk("key=%08x from=%08x", + __entry->key, __entry->keyring) + ); + +TRACE_EVENT(key_move, + TP_PROTO(const struct key *from, const struct key *to, + const struct key *key), + + TP_ARGS(from, to, key), + + TP_STRUCT__entry( + __field(key_serial_t, from) + __field(key_serial_t, to) + __field(key_serial_t, key) + ), + + TP_fast_assign( + __entry->from = from->serial; + __entry->to = to->serial; + __entry->key = key->serial; + ), + + TP_printk("key=%08x from=%08x to=%08x", + __entry->key, __entry->from, __entry->to) + ); + +TRACE_EVENT(key_clear, + TP_PROTO(const struct key *keyring), + TP_ARGS(keyring), + TP_STRUCT__entry( + __field(key_serial_t, keyring) + ), + TP_fast_assign( + __entry->keyring = keyring->serial; + ), + TP_printk("key=%08x", + __entry->keyring) + ); + +TRACE_EVENT(key_revoke, + TP_PROTO(const struct key *key), + TP_ARGS(key), + TP_STRUCT__entry( + __field(key_serial_t, key) + ), + TP_fast_assign( + __entry->key = key->serial; + ), + TP_printk("key=%08x", + __entry->key) + ); + +TRACE_EVENT(key_invalidate, + TP_PROTO(const struct key *key), + TP_ARGS(key), + TP_STRUCT__entry( + __field(key_serial_t, key) + ), + TP_fast_assign( + __entry->key = key->serial; + ), + TP_printk("key=%08x", + __entry->key) + ); + +TRACE_EVENT(key_gc, + TP_PROTO(const struct key *key), + TP_ARGS(key), + TP_STRUCT__entry( + __field(key_serial_t, key) + ), + TP_fast_assign( + __entry->key = key->serial; + ), + TP_printk("key=%08x", + __entry->key) + ); + +#undef EM +#undef E_ +#endif /* _TRACE_KEY_H */ + +/* This part must be outside protection */ +#include diff --git a/security/keys/gc.c b/security/keys/gc.c index 7d687b0962b1..47f857653854 100644 --- a/security/keys/gc.c +++ b/security/keys/gc.c @@ -141,6 +141,7 @@ static noinline void key_gc_unused_keys(struct list_head *keys) list_del(&key->graveyard_link); + trace_key_gc(key); kdebug("- %u", key->serial); key_check(key); @@ -163,6 +164,8 @@ static noinline void key_gc_unused_keys(struct list_head *keys) key_put_tag(key->domain_tag); kfree(key->description); + trace_key_ref(key->serial, refcount_read(&key->usage), + key_trace_ref_free, 0); memzero_explicit(key, sizeof(*key)); kmem_cache_free(key_jar, key); } @@ -331,6 +334,7 @@ static void key_garbage_collector(struct work_struct *work) */ found_unreferenced_key: kdebug("unrefd key %d", key->serial); + trace_key_ref(key->serial, refcount_read(&key->usage), key_trace_ref_gc, 0); rb_erase(&key->serial_node, &key_serial_tree); spin_unlock(&key_serial_lock); diff --git a/security/keys/internal.h b/security/keys/internal.h index 2cffa6dc8255..87600683a7f5 100644 --- a/security/keys/internal.h +++ b/security/keys/internal.h @@ -19,6 +19,8 @@ #include #include #include +#include +#include struct iovec; @@ -43,25 +45,6 @@ extern struct key_type key_type_user; extern struct key_type key_type_logon; /*****************************************************************************/ -/* - * Keep track of keys for a user. - * - * This needs to be separate to user_struct to avoid a refcount-loop - * (user_struct pins some keyrings which pin this struct). - * - * We also keep track of keys under request from userspace for this UID here. - */ -struct key_user { - struct rb_node node; - struct mutex cons_lock; /* construction initiation lock */ - spinlock_t lock; - refcount_t usage; /* for accessing qnkeys & qnbytes */ - atomic_t nkeys; /* number of keys */ - atomic_t nikeys; /* number of instantiated keys */ - kuid_t uid; - int qnkeys; /* number of keys allocated to this user */ - int qnbytes; /* number of bytes allocated to this user */ -}; extern struct rb_root key_user_tree; extern spinlock_t key_user_lock; @@ -211,26 +194,6 @@ extern struct key *request_key_auth_new(struct key *target, extern struct key *key_get_instantiation_authkey(key_serial_t target_id); -/* - * Determine whether a key is dead. - */ -static inline bool key_is_dead(const struct key *key, time64_t limit) -{ - time64_t expiry = key->expiry; - - if (expiry != TIME64_MAX) { - if (!(key->type->flags & KEY_TYPE_INSTANT_REAP)) - expiry += key_gc_delay; - if (expiry <= limit) - return true; - } - - return - key->flags & ((1 << KEY_FLAG_DEAD) | - (1 << KEY_FLAG_INVALIDATED)) || - key->domain_tag->removed; -} - /* * keyctl() functions */ diff --git a/security/keys/key.c b/security/keys/key.c index 3d7d185019d3..28a4128ff103 100644 --- a/security/keys/key.c +++ b/security/keys/key.c @@ -14,6 +14,7 @@ #include #include #include +#define CREATE_TRACE_POINTS #include "internal.h" struct kmem_cache *key_jar; @@ -264,12 +265,15 @@ struct key *key_alloc(struct key_type *type, const char *desc, if (!(flags & KEY_ALLOC_QUOTA_OVERRUN)) { if (user->qnkeys + 1 > maxkeys || user->qnbytes + quotalen > maxbytes || - user->qnbytes + quotalen < user->qnbytes) + user->qnbytes + quotalen < user->qnbytes) { + trace_key_edquot(user, maxkeys, maxbytes, quotalen); goto no_quota; + } } user->qnkeys++; user->qnbytes += quotalen; + trace_key_quota(user, +1, quotalen); spin_unlock_irqrestore(&user->lock, irqflags); } @@ -319,7 +323,10 @@ struct key *key_alloc(struct key_type *type, const char *desc, /* publish the key by giving it a serial number */ refcount_inc(&key->domain_tag->usage); atomic_inc(&user->nkeys); + trace_key_quota(user, 0, 0); key_alloc_serial(key); + trace_key_alloc(key); + trace_key_ref(key->serial, 1, key_trace_ref_alloc, __builtin_return_address(0)); error: return key; @@ -331,6 +338,7 @@ struct key *key_alloc(struct key_type *type, const char *desc, spin_lock_irqsave(&user->lock, irqflags); user->qnkeys--; user->qnbytes -= quotalen; + trace_key_quota(user, -1, -quotalen); spin_unlock_irqrestore(&user->lock, irqflags); } key_user_put(user); @@ -344,6 +352,7 @@ struct key *key_alloc(struct key_type *type, const char *desc, spin_lock_irqsave(&user->lock, irqflags); user->qnkeys--; user->qnbytes -= quotalen; + trace_key_quota(user, -1, quotalen); spin_unlock_irqrestore(&user->lock, irqflags); } key_user_put(user); @@ -388,11 +397,13 @@ int key_payload_reserve(struct key *key, size_t datalen) if (delta > 0 && (key->user->qnbytes + delta > maxbytes || key->user->qnbytes + delta < key->user->qnbytes)) { + trace_key_edquot(key->user, 0, maxbytes, datalen); ret = -EDQUOT; } else { key->user->qnbytes += delta; key->quotalen += delta; + trace_key_quota(key->user, 0, delta); } spin_unlock_irqrestore(&key->user->lock, flags); } @@ -447,6 +458,7 @@ static int __key_instantiate_and_link(struct key *key, if (ret == 0) { /* mark the key as being instantiated */ atomic_inc(&key->user->nikeys); + trace_key_instantiate(key, prep); mark_key_instantiated(key, 0); notify_key(key, NOTIFY_KEY_INSTANTIATED, 0); @@ -604,6 +616,7 @@ int key_reject_and_link(struct key *key, if (key->state == KEY_IS_UNINSTANTIATED) { /* mark the key as being negatively instantiated */ atomic_inc(&key->user->nikeys); + trace_key_reject(key, -error); mark_key_instantiated(key, -error); notify_key(key, NOTIFY_KEY_INSTANTIATED, -error); key_set_expiry(key, ktime_get_real_seconds() + timeout); @@ -635,6 +648,39 @@ int key_reject_and_link(struct key *key, } EXPORT_SYMBOL(key_reject_and_link); +/** + * key_get - Get a reference on a key + * @key: The key to get a reference on. + * + * Get a reference on a key, if not NULL, and return the parameter. + */ +noinline struct key *key_get(struct key *key) +{ + if (key) { + int r; + + __refcount_inc(&key->usage, &r); + trace_key_ref(key->serial, r + 1, key_trace_ref_get, + __builtin_return_address(0)); + } + return key; +} +EXPORT_SYMBOL(key_get); + +/* + * Get a ref on a key if its refcount is not non-zero. + */ +noinline struct key *key_try_get(struct key *key) +{ + int r; + + if (!__refcount_inc_not_zero(&key->usage, &r)) + return NULL; + trace_key_ref(key->serial, r + 1, key_trace_ref_try_get, + __builtin_return_address(0)); + return key; +} + /** * key_put - Discard a reference to a key. * @key: The key to discard a reference from. @@ -643,12 +689,19 @@ EXPORT_SYMBOL(key_reject_and_link); * schedule the cleanup task to come and pull it out of the tree in process * context at some later time. */ -void key_put(struct key *key) +noinline void key_put(struct key *key) { if (key) { + key_serial_t serial = key->serial; + bool zero; + int r; + key_check(key); - if (refcount_dec_and_test(&key->usage)) { + zero = __refcount_dec_and_test(&key->usage, &r); + trace_key_ref(serial, r - 1, key_trace_ref_put, + __builtin_return_address(0)); + if (zero) { unsigned long flags; /* deal with the user's key tracking and quota */ @@ -656,6 +709,7 @@ void key_put(struct key *key) spin_lock_irqsave(&key->user->lock, flags); key->user->qnkeys--; key->user->qnbytes -= key->quotalen; + trace_key_quota(key->user, -1, -key->quotalen); spin_unlock_irqrestore(&key->user->lock, flags); } schedule_work(&key_gc_work); @@ -695,7 +749,7 @@ struct key *key_lookup(key_serial_t id) /* A key is allowed to be looked up only if someone still owns a * reference to it - otherwise it's awaiting the gc. */ - if (!refcount_inc_not_zero(&key->usage)) + if (!key_try_get(key)) goto not_found; error: @@ -779,6 +833,7 @@ static inline key_ref_t __key_update(key_ref_t key_ref, ret = key->type->update(key, prep); if (ret == 0) { /* Updating a negative key positively instantiates it */ + trace_key_update(key, prep); mark_key_instantiated(key, 0); notify_key(key, NOTIFY_KEY_UPDATED, 0); } @@ -1103,6 +1158,7 @@ int key_update(key_ref_t key_ref, const void *payload, size_t plen) ret = key->type->update(key, &prep); if (ret == 0) { /* Updating a negative key positively instantiates it */ + trace_key_update(key, &prep); mark_key_instantiated(key, 0); notify_key(key, NOTIFY_KEY_UPDATED, 0); } @@ -1138,6 +1194,7 @@ void key_revoke(struct key *key) */ down_write_nested(&key->sem, 1); if (!test_and_set_bit(KEY_FLAG_REVOKED, &key->flags)) { + trace_key_revoke(key); notify_key(key, NOTIFY_KEY_REVOKED, 0); if (key->type->revoke) key->type->revoke(key); @@ -1170,6 +1227,7 @@ void key_invalidate(struct key *key) if (!test_bit(KEY_FLAG_INVALIDATED, &key->flags)) { down_write_nested(&key->sem, 1); if (!test_and_set_bit(KEY_FLAG_INVALIDATED, &key->flags)) { + trace_key_invalidate(key); notify_key(key, NOTIFY_KEY_INVALIDATED, 0); key_schedule_gc_links(); } diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c index 4bc3e9398ee3..8fa4ced5c915 100644 --- a/security/keys/keyctl.c +++ b/security/keys/keyctl.c @@ -1020,11 +1020,13 @@ long keyctl_chown_key(key_serial_t id, uid_t user, gid_t group) newowner->qnkeys++; newowner->qnbytes += key->quotalen; + trace_key_quota(newowner, +1, key->quotalen); spin_unlock_irqrestore(&newowner->lock, flags); spin_lock_irqsave(&key->user->lock, flags); key->user->qnkeys--; key->user->qnbytes -= key->quotalen; + trace_key_quota(newowner, -1, -key->quotalen); spin_unlock_irqrestore(&key->user->lock, flags); } diff --git a/security/keys/keyring.c b/security/keys/keyring.c index 4448758f643a..d67a60142318 100644 --- a/security/keys/keyring.c +++ b/security/keys/keyring.c @@ -920,7 +920,7 @@ key_ref_t keyring_search_rcu(key_ref_t keyring_ref, ctx->now = ktime_get_real_seconds(); if (search_nested_keyrings(keyring, ctx)) - __key_get(key_ref_to_ptr(ctx->result)); + key_ref_get(ctx->result); return ctx->result; } @@ -1122,7 +1122,7 @@ key_ref_t find_key_to_update(key_ref_t keyring_ref, kleave(" = NULL [x]"); return NULL; } - __key_get(key); + key_get(key); kleave(" = {%d}", key->serial); return make_key_ref(key, is_key_possessed(keyring_ref)); } @@ -1174,7 +1174,7 @@ struct key *find_keyring_by_name(const char *name, bool uid_keyring) /* 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)) + if (!key_try_get(keyring)) continue; keyring->last_used_at = ktime_get_real_seconds(); goto out; @@ -1367,7 +1367,8 @@ int __key_link_check_live_key(struct key *keyring, struct key *key) void __key_link(struct key *keyring, struct key *key, struct assoc_array_edit **_edit) { - __key_get(key); + key_get(key); + trace_key_link(keyring, key); assoc_array_insert_set_object(*_edit, keyring_key_to_ptr(key)); assoc_array_apply_edit(*_edit); *_edit = NULL; @@ -1506,6 +1507,7 @@ static int __key_unlink_begin(struct key *keyring, struct key *key, static void __key_unlink(struct key *keyring, struct key *key, struct assoc_array_edit **_edit) { + trace_key_unlink(keyring, key); assoc_array_apply_edit(*_edit); notify_key(keyring, NOTIFY_KEY_UNLINKED, key_serial(key)); *_edit = NULL; @@ -1625,6 +1627,7 @@ int key_move(struct key *key, if (ret < 0) goto error; + trace_key_move(from_keyring, to_keyring, key); __key_unlink(from_keyring, key, &from_edit); __key_link(to_keyring, key, &to_edit); error: @@ -1654,6 +1657,7 @@ int keyring_clear(struct key *keyring) down_write(&keyring->sem); + trace_key_clear(keyring); edit = assoc_array_clear(&keyring->keys, &keyring_assoc_array_ops); if (IS_ERR(edit)) { ret = PTR_ERR(edit); @@ -1687,6 +1691,39 @@ static void keyring_revoke(struct key *keyring) } } +/* + * Determine whether a key is dead. + */ +static bool key_is_dead(const struct key *key, time64_t limit) +{ + time64_t expiry = key->expiry; + + if (expiry != TIME64_MAX) { + if (!(key->type->flags & KEY_TYPE_INSTANT_REAP)) + expiry += key_gc_delay; + if (expiry <= limit) { + trace_key_dead(key, key_trace_dead_expired); + return true; + } + } + + if (test_bit(KEY_FLAG_DEAD, &key->flags)) { + trace_key_dead(key, key_trace_dead_type_removed); + return true; + } + + if (test_bit(KEY_FLAG_INVALIDATED, &key->flags)) { + trace_key_dead(key, key_trace_dead_invalidated); + return true; + } + + if (key->domain_tag->removed) { + trace_key_dead(key, key_trace_dead_domain_removed); + return true; + } + return false; +} + static bool keyring_gc_select_iterator(void *object, void *iterator_data) { struct key *key = keyring_ptr_to_key(object); diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c index b5d5333ab330..01291b2d0888 100644 --- a/security/keys/process_keys.c +++ b/security/keys/process_keys.c @@ -333,7 +333,7 @@ int install_session_keyring_to_cred(struct cred *cred, struct key *keyring) if (IS_ERR(keyring)) return PTR_ERR(keyring); } else { - __key_get(keyring); + key_get(keyring); } /* install the keyring */ @@ -641,7 +641,7 @@ key_ref_t lookup_user_key(key_serial_t id, unsigned long lflags, } key = ctx.cred->thread_keyring; - __key_get(key); + key_get(key); key_ref = make_key_ref(key, 1); break; @@ -658,8 +658,7 @@ key_ref_t lookup_user_key(key_serial_t id, unsigned long lflags, goto reget_creds; } - key = ctx.cred->process_keyring; - __key_get(key); + key = key_get(ctx.cred->process_keyring); key_ref = make_key_ref(key, 1); break; @@ -688,8 +687,7 @@ key_ref_t lookup_user_key(key_serial_t id, unsigned long lflags, goto reget_creds; } - key = ctx.cred->session_keyring; - __key_get(key); + key = key_get(ctx.cred->session_keyring); key_ref = make_key_ref(key, 1); break; @@ -717,7 +715,7 @@ key_ref_t lookup_user_key(key_serial_t id, unsigned long lflags, if (!key) goto error; - __key_get(key); + key_get(key); key_ref = make_key_ref(key, 1); break; @@ -732,8 +730,7 @@ key_ref_t lookup_user_key(key_serial_t id, unsigned long lflags, key = NULL; } else { rka = ctx.cred->request_key_auth->payload.data[0]; - key = rka->dest_keyring; - __key_get(key); + key = key_get(rka->dest_keyring); } up_read(&ctx.cred->request_key_auth->sem); if (!key)