From 9a56c2db49e7349c7963f0ce66c1ef578d44ebd3 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Wed, 8 Feb 2012 07:53:04 -0800 Subject: userns: Convert security/keys to the new userns infrastructure - Replace key_user ->user_ns equality checks with kuid_has_mapping checks. - Use from_kuid to generate key descriptions - Use kuid_t and kgid_t and the associated helpers instead of uid_t and gid_t - Avoid potential problems with file descriptor passing by displaying keys in the user namespace of the opener of key status proc files. Cc: linux-security-module@vger.kernel.org Cc: keyrings@linux-nfs.org Cc: David Howells Signed-off-by: Eric W. Biederman --- security/keys/internal.h | 6 ++---- security/keys/key.c | 23 +++++++------------- security/keys/keyctl.c | 50 ++++++++++++++++++++++++++------------------ security/keys/keyring.c | 4 ++-- security/keys/permission.c | 14 ++++--------- security/keys/proc.c | 44 +++++++++++++++++++------------------- security/keys/process_keys.c | 15 ++++++------- security/keys/request_key.c | 6 +++--- 8 files changed, 79 insertions(+), 83 deletions(-) (limited to 'security/keys') diff --git a/security/keys/internal.h b/security/keys/internal.h index 22ff05269e3d..8bbefc3b55d4 100644 --- a/security/keys/internal.h +++ b/security/keys/internal.h @@ -52,8 +52,7 @@ struct key_user { atomic_t usage; /* for accessing qnkeys & qnbytes */ atomic_t nkeys; /* number of keys */ atomic_t nikeys; /* number of instantiated keys */ - uid_t uid; - struct user_namespace *user_ns; + kuid_t uid; int qnkeys; /* number of keys allocated to this user */ int qnbytes; /* number of bytes allocated to this user */ }; @@ -62,8 +61,7 @@ extern struct rb_root key_user_tree; extern spinlock_t key_user_lock; extern struct key_user root_key_user; -extern struct key_user *key_user_lookup(uid_t uid, - struct user_namespace *user_ns); +extern struct key_user *key_user_lookup(kuid_t uid); extern void key_user_put(struct key_user *user); /* diff --git a/security/keys/key.c b/security/keys/key.c index 50d96d4e06f2..4289c5ba2710 100644 --- a/security/keys/key.c +++ b/security/keys/key.c @@ -18,7 +18,6 @@ #include #include #include -#include #include "internal.h" struct kmem_cache *key_jar; @@ -52,7 +51,7 @@ void __key_check(const struct key *key) * Get the key quota record for a user, allocating a new record if one doesn't * already exist. */ -struct key_user *key_user_lookup(uid_t uid, struct user_namespace *user_ns) +struct key_user *key_user_lookup(kuid_t uid) { struct key_user *candidate = NULL, *user; struct rb_node *parent = NULL; @@ -67,13 +66,9 @@ try_again: parent = *p; user = rb_entry(parent, struct key_user, node); - if (uid < user->uid) + if (uid_lt(uid, user->uid)) p = &(*p)->rb_left; - else if (uid > user->uid) - p = &(*p)->rb_right; - else if (user_ns < user->user_ns) - p = &(*p)->rb_left; - else if (user_ns > user->user_ns) + else if (uid_gt(uid, user->uid)) p = &(*p)->rb_right; else goto found; @@ -102,7 +97,6 @@ try_again: atomic_set(&candidate->nkeys, 0); atomic_set(&candidate->nikeys, 0); candidate->uid = uid; - candidate->user_ns = get_user_ns(user_ns); candidate->qnkeys = 0; candidate->qnbytes = 0; spin_lock_init(&candidate->lock); @@ -131,7 +125,6 @@ void key_user_put(struct key_user *user) if (atomic_dec_and_lock(&user->usage, &key_user_lock)) { rb_erase(&user->node, &key_user_tree); spin_unlock(&key_user_lock); - put_user_ns(user->user_ns); kfree(user); } @@ -229,7 +222,7 @@ serial_exists: * key_alloc() calls don't race with module unloading. */ struct key *key_alloc(struct key_type *type, const char *desc, - uid_t uid, gid_t gid, const struct cred *cred, + kuid_t uid, kgid_t gid, const struct cred *cred, key_perm_t perm, unsigned long flags) { struct key_user *user = NULL; @@ -253,16 +246,16 @@ struct key *key_alloc(struct key_type *type, const char *desc, quotalen = desclen + type->def_datalen; /* get hold of the key tracking for this user */ - user = key_user_lookup(uid, cred->user_ns); + user = key_user_lookup(uid); if (!user) goto no_memory_1; /* check that the user's quota permits allocation of another key and * its description */ if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) { - unsigned maxkeys = (uid == 0) ? + unsigned maxkeys = uid_eq(uid, GLOBAL_ROOT_UID) ? key_quota_root_maxkeys : key_quota_maxkeys; - unsigned maxbytes = (uid == 0) ? + unsigned maxbytes = uid_eq(uid, GLOBAL_ROOT_UID) ? key_quota_root_maxbytes : key_quota_maxbytes; spin_lock(&user->lock); @@ -380,7 +373,7 @@ int key_payload_reserve(struct key *key, size_t datalen) /* contemplate the quota adjustment */ if (delta != 0 && test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) { - unsigned maxbytes = (key->user->uid == 0) ? + unsigned maxbytes = uid_eq(key->user->uid, GLOBAL_ROOT_UID) ? key_quota_root_maxbytes : key_quota_maxbytes; spin_lock(&key->user->lock); diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c index 3364fbf46807..1ecc0f79906e 100644 --- a/security/keys/keyctl.c +++ b/security/keys/keyctl.c @@ -569,8 +569,8 @@ okay: ret = snprintf(tmpbuf, PAGE_SIZE - 1, "%s;%d;%d;%08x;%s", key->type->name, - key->uid, - key->gid, + from_kuid_munged(current_user_ns(), key->uid), + from_kgid_munged(current_user_ns(), key->gid), key->perm, key->description ?: ""); @@ -766,15 +766,25 @@ error: * * If successful, 0 will be returned. */ -long keyctl_chown_key(key_serial_t id, uid_t uid, gid_t gid) +long keyctl_chown_key(key_serial_t id, uid_t user, gid_t group) { struct key_user *newowner, *zapowner = NULL; struct key *key; key_ref_t key_ref; long ret; + kuid_t uid; + kgid_t gid; + + uid = make_kuid(current_user_ns(), user); + gid = make_kgid(current_user_ns(), group); + ret = -EINVAL; + if ((user != (uid_t) -1) && !uid_valid(uid)) + goto error; + if ((group != (gid_t) -1) && !gid_valid(gid)) + goto error; ret = 0; - if (uid == (uid_t) -1 && gid == (gid_t) -1) + if (user == (uid_t) -1 && group == (gid_t) -1) goto error; key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL, @@ -792,27 +802,27 @@ long keyctl_chown_key(key_serial_t id, uid_t uid, gid_t gid) if (!capable(CAP_SYS_ADMIN)) { /* only the sysadmin can chown a key to some other UID */ - if (uid != (uid_t) -1 && key->uid != uid) + if (user != (uid_t) -1 && !uid_eq(key->uid, uid)) goto error_put; /* only the sysadmin can set the key's GID to a group other * than one of those that the current process subscribes to */ - if (gid != (gid_t) -1 && gid != key->gid && !in_group_p(gid)) + if (group != (gid_t) -1 && !gid_eq(gid, key->gid) && !in_group_p(gid)) goto error_put; } /* change the UID */ - if (uid != (uid_t) -1 && uid != key->uid) { + if (user != (uid_t) -1 && !uid_eq(uid, key->uid)) { ret = -ENOMEM; - newowner = key_user_lookup(uid, current_user_ns()); + newowner = key_user_lookup(uid); if (!newowner) goto error_put; /* transfer the quota burden to the new user */ if (test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) { - unsigned maxkeys = (uid == 0) ? + unsigned maxkeys = uid_eq(uid, GLOBAL_ROOT_UID) ? key_quota_root_maxkeys : key_quota_maxkeys; - unsigned maxbytes = (uid == 0) ? + unsigned maxbytes = uid_eq(uid, GLOBAL_ROOT_UID) ? key_quota_root_maxbytes : key_quota_maxbytes; spin_lock(&newowner->lock); @@ -846,7 +856,7 @@ long keyctl_chown_key(key_serial_t id, uid_t uid, gid_t gid) } /* change the GID */ - if (gid != (gid_t) -1) + if (group != (gid_t) -1) key->gid = gid; ret = 0; @@ -897,7 +907,7 @@ long keyctl_setperm_key(key_serial_t id, key_perm_t perm) down_write(&key->sem); /* if we're not the sysadmin, we can only change a key that we own */ - if (capable(CAP_SYS_ADMIN) || key->uid == current_fsuid()) { + if (capable(CAP_SYS_ADMIN) || uid_eq(key->uid, current_fsuid())) { key->perm = perm; ret = 0; } @@ -1507,18 +1517,18 @@ long keyctl_session_to_parent(void) /* the parent must have the same effective ownership and mustn't be * SUID/SGID */ - if (pcred->uid != mycred->euid || - pcred->euid != mycred->euid || - pcred->suid != mycred->euid || - pcred->gid != mycred->egid || - pcred->egid != mycred->egid || - pcred->sgid != mycred->egid) + if (!uid_eq(pcred->uid, mycred->euid) || + !uid_eq(pcred->euid, mycred->euid) || + !uid_eq(pcred->suid, mycred->euid) || + !gid_eq(pcred->gid, mycred->egid) || + !gid_eq(pcred->egid, mycred->egid) || + !gid_eq(pcred->sgid, mycred->egid)) goto unlock; /* the keyrings must have the same UID */ if ((pcred->tgcred->session_keyring && - pcred->tgcred->session_keyring->uid != mycred->euid) || - mycred->tgcred->session_keyring->uid != mycred->euid) + !uid_eq(pcred->tgcred->session_keyring->uid, mycred->euid)) || + !uid_eq(mycred->tgcred->session_keyring->uid, mycred->euid)) goto unlock; /* cancel an already pending keyring replacement */ diff --git a/security/keys/keyring.c b/security/keys/keyring.c index 81e7852d281d..a5f5c4b6edc5 100644 --- a/security/keys/keyring.c +++ b/security/keys/keyring.c @@ -256,7 +256,7 @@ error: /* * Allocate a keyring and link into the destination keyring. */ -struct key *keyring_alloc(const char *description, uid_t uid, gid_t gid, +struct key *keyring_alloc(const char *description, kuid_t uid, kgid_t gid, const struct cred *cred, unsigned long flags, struct key *dest) { @@ -612,7 +612,7 @@ struct key *find_keyring_by_name(const char *name, bool skip_perm_check) &keyring_name_hash[bucket], type_data.link ) { - if (keyring->user->user_ns != current_user_ns()) + if (!kuid_has_mapping(current_user_ns(), keyring->user->uid)) continue; if (test_bit(KEY_FLAG_REVOKED, &keyring->flags)) diff --git a/security/keys/permission.c b/security/keys/permission.c index 0b4d019e027d..efcc0c855a0d 100644 --- a/security/keys/permission.c +++ b/security/keys/permission.c @@ -36,33 +36,27 @@ int key_task_permission(const key_ref_t key_ref, const struct cred *cred, key = key_ref_to_ptr(key_ref); - if (key->user->user_ns != cred->user_ns) - goto use_other_perms; - /* use the second 8-bits of permissions for keys the caller owns */ - if (key->uid == cred->fsuid) { + if (uid_eq(key->uid, cred->fsuid)) { kperm = key->perm >> 16; goto use_these_perms; } /* use the third 8-bits of permissions for keys the caller has a group * membership in common with */ - if (key->gid != -1 && key->perm & KEY_GRP_ALL) { - if (key->gid == cred->fsgid) { + if (gid_valid(key->gid) && key->perm & KEY_GRP_ALL) { + if (gid_eq(key->gid, cred->fsgid)) { kperm = key->perm >> 8; goto use_these_perms; } - ret = groups_search(cred->group_info, - make_kgid(current_user_ns(), key->gid)); + ret = groups_search(cred->group_info, key->gid); if (ret) { kperm = key->perm >> 8; goto use_these_perms; } } -use_other_perms: - /* otherwise use the least-significant 8-bits */ kperm = key->perm; diff --git a/security/keys/proc.c b/security/keys/proc.c index 30d1ddfd9cef..217b6855e815 100644 --- a/security/keys/proc.c +++ b/security/keys/proc.c @@ -88,14 +88,14 @@ __initcall(key_proc_init); */ #ifdef CONFIG_KEYS_DEBUG_PROC_KEYS -static struct rb_node *key_serial_next(struct rb_node *n) +static struct rb_node *key_serial_next(struct seq_file *p, struct rb_node *n) { - struct user_namespace *user_ns = current_user_ns(); + struct user_namespace *user_ns = seq_user_ns(p); n = rb_next(n); while (n) { struct key *key = rb_entry(n, struct key, serial_node); - if (key->user->user_ns == user_ns) + if (kuid_has_mapping(user_ns, key->user->uid)) break; n = rb_next(n); } @@ -107,9 +107,9 @@ static int proc_keys_open(struct inode *inode, struct file *file) return seq_open(file, &proc_keys_ops); } -static struct key *find_ge_key(key_serial_t id) +static struct key *find_ge_key(struct seq_file *p, key_serial_t id) { - struct user_namespace *user_ns = current_user_ns(); + struct user_namespace *user_ns = seq_user_ns(p); struct rb_node *n = key_serial_tree.rb_node; struct key *minkey = NULL; @@ -132,7 +132,7 @@ static struct key *find_ge_key(key_serial_t id) return NULL; for (;;) { - if (minkey->user->user_ns == user_ns) + if (kuid_has_mapping(user_ns, minkey->user->uid)) return minkey; n = rb_next(&minkey->serial_node); if (!n) @@ -151,7 +151,7 @@ static void *proc_keys_start(struct seq_file *p, loff_t *_pos) if (*_pos > INT_MAX) return NULL; - key = find_ge_key(pos); + key = find_ge_key(p, pos); if (!key) return NULL; *_pos = key->serial; @@ -168,7 +168,7 @@ static void *proc_keys_next(struct seq_file *p, void *v, loff_t *_pos) { struct rb_node *n; - n = key_serial_next(v); + n = key_serial_next(p, v); if (n) *_pos = key_node_serial(n); return n; @@ -254,8 +254,8 @@ static int proc_keys_show(struct seq_file *m, void *v) atomic_read(&key->usage), xbuf, key->perm, - key->uid, - key->gid, + from_kuid_munged(seq_user_ns(m), key->uid), + from_kgid_munged(seq_user_ns(m), key->gid), key->type->name); #undef showflag @@ -270,26 +270,26 @@ static int proc_keys_show(struct seq_file *m, void *v) #endif /* CONFIG_KEYS_DEBUG_PROC_KEYS */ -static struct rb_node *__key_user_next(struct rb_node *n) +static struct rb_node *__key_user_next(struct user_namespace *user_ns, struct rb_node *n) { while (n) { struct key_user *user = rb_entry(n, struct key_user, node); - if (user->user_ns == current_user_ns()) + if (kuid_has_mapping(user_ns, user->uid)) break; n = rb_next(n); } return n; } -static struct rb_node *key_user_next(struct rb_node *n) +static struct rb_node *key_user_next(struct user_namespace *user_ns, struct rb_node *n) { - return __key_user_next(rb_next(n)); + return __key_user_next(user_ns, rb_next(n)); } -static struct rb_node *key_user_first(struct rb_root *r) +static struct rb_node *key_user_first(struct user_namespace *user_ns, struct rb_root *r) { struct rb_node *n = rb_first(r); - return __key_user_next(n); + return __key_user_next(user_ns, n); } /* @@ -309,10 +309,10 @@ static void *proc_key_users_start(struct seq_file *p, loff_t *_pos) spin_lock(&key_user_lock); - _p = key_user_first(&key_user_tree); + _p = key_user_first(seq_user_ns(p), &key_user_tree); while (pos > 0 && _p) { pos--; - _p = key_user_next(_p); + _p = key_user_next(seq_user_ns(p), _p); } return _p; @@ -321,7 +321,7 @@ static void *proc_key_users_start(struct seq_file *p, loff_t *_pos) static void *proc_key_users_next(struct seq_file *p, void *v, loff_t *_pos) { (*_pos)++; - return key_user_next((struct rb_node *)v); + return key_user_next(seq_user_ns(p), (struct rb_node *)v); } static void proc_key_users_stop(struct seq_file *p, void *v) @@ -334,13 +334,13 @@ static int proc_key_users_show(struct seq_file *m, void *v) { struct rb_node *_p = v; struct key_user *user = rb_entry(_p, struct key_user, node); - unsigned maxkeys = (user->uid == 0) ? + unsigned maxkeys = uid_eq(user->uid, GLOBAL_ROOT_UID) ? key_quota_root_maxkeys : key_quota_maxkeys; - unsigned maxbytes = (user->uid == 0) ? + unsigned maxbytes = uid_eq(user->uid, GLOBAL_ROOT_UID) ? key_quota_root_maxbytes : key_quota_maxbytes; seq_printf(m, "%5u: %5d %d/%d %d/%d %d/%d\n", - user->uid, + from_kuid_munged(seq_user_ns(m), user->uid), atomic_read(&user->usage), atomic_read(&user->nkeys), atomic_read(&user->nikeys), diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c index 54339cfd6734..a58f712605d8 100644 --- a/security/keys/process_keys.c +++ b/security/keys/process_keys.c @@ -34,8 +34,7 @@ struct key_user root_key_user = { .lock = __SPIN_LOCK_UNLOCKED(root_key_user.lock), .nkeys = ATOMIC_INIT(2), .nikeys = ATOMIC_INIT(2), - .uid = 0, - .user_ns = &init_user_ns, + .uid = GLOBAL_ROOT_UID, }; /* @@ -48,11 +47,13 @@ int install_user_keyrings(void) struct key *uid_keyring, *session_keyring; char buf[20]; int ret; + uid_t uid; cred = current_cred(); user = cred->user; + uid = from_kuid(cred->user_ns, user->uid); - kenter("%p{%u}", user, user->uid); + kenter("%p{%u}", user, uid); if (user->uid_keyring) { kleave(" = 0 [exist]"); @@ -67,11 +68,11 @@ int install_user_keyrings(void) * - there may be one in existence already as it may have been * pinned by a session, but the user_struct pointing to it * may have been destroyed by setuid */ - sprintf(buf, "_uid.%u", user->uid); + sprintf(buf, "_uid.%u", uid); uid_keyring = find_keyring_by_name(buf, true); if (IS_ERR(uid_keyring)) { - uid_keyring = keyring_alloc(buf, user->uid, (gid_t) -1, + uid_keyring = keyring_alloc(buf, user->uid, INVALID_GID, cred, KEY_ALLOC_IN_QUOTA, NULL); if (IS_ERR(uid_keyring)) { @@ -82,12 +83,12 @@ int install_user_keyrings(void) /* get a default session keyring (which might also exist * already) */ - sprintf(buf, "_uid_ses.%u", user->uid); + sprintf(buf, "_uid_ses.%u", uid); session_keyring = find_keyring_by_name(buf, true); if (IS_ERR(session_keyring)) { session_keyring = - keyring_alloc(buf, user->uid, (gid_t) -1, + keyring_alloc(buf, user->uid, INVALID_GID, cred, KEY_ALLOC_IN_QUOTA, NULL); if (IS_ERR(session_keyring)) { ret = PTR_ERR(session_keyring); diff --git a/security/keys/request_key.c b/security/keys/request_key.c index 000e75017520..66e21184b559 100644 --- a/security/keys/request_key.c +++ b/security/keys/request_key.c @@ -139,8 +139,8 @@ static int call_sbin_request_key(struct key_construction *cons, goto error_link; /* record the UID and GID */ - sprintf(uid_str, "%d", cred->fsuid); - sprintf(gid_str, "%d", cred->fsgid); + sprintf(uid_str, "%d", from_kuid(&init_user_ns, cred->fsuid)); + sprintf(gid_str, "%d", from_kgid(&init_user_ns, cred->fsgid)); /* we say which key is under construction */ sprintf(key_str, "%d", key->serial); @@ -442,7 +442,7 @@ static struct key *construct_key_and_link(struct key_type *type, kenter(""); - user = key_user_lookup(current_fsuid(), current_user_ns()); + user = key_user_lookup(current_fsuid()); if (!user) return ERR_PTR(-ENOMEM); -- cgit v1.2.3-59-g8ed1b