From mboxrd@z Thu Jan 1 00:00:00 1970 From: "\"Eric W. Beiderman" Subject: [PATCH 15/43] userns: Disassociate user_struct from the user_namespace. Date: Sat, 7 Apr 2012 22:15:11 -0700 Message-ID: <1333862139-31737-15-git-send-email-ebiederm@xmission.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Cc: Linux Containers , Cyrill Gorcunov , linux-security-module-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Al Viro , linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Andrew Morton , Linus Torvalds , "Eric W. Biederman" List-Id: containers.vger.kernel.org From: Eric W. Biederman Modify alloc_uid to take a kuid and make the user hash table global. Stop holding a reference to the user namespace in struct user_struct. This simplifies the code and makes the per user accounting not care about which user namespace a uid happens to appear in. Acked-by: Serge Hallyn Signed-off-by: Eric W. Biederman --- fs/ioprio.c | 18 ++++++++++++++---- include/linux/sched.h | 8 ++++---- include/linux/user_namespace.h | 4 ---- kernel/sys.c | 34 +++++++++++++++++++++++----------- kernel/user.c | 28 +++++++++++++--------------- kernel/user_namespace.c | 6 +----- 6 files changed, 55 insertions(+), 43 deletions(-) diff --git a/fs/ioprio.c b/fs/ioprio.c index 0f1b951..8e35e96 100644 --- a/fs/ioprio.c +++ b/fs/ioprio.c @@ -65,6 +65,7 @@ SYSCALL_DEFINE3(ioprio_set, int, which, int, who, int, ioprio) struct task_struct *p, *g; struct user_struct *user; struct pid *pgrp; + kuid_t uid; int ret; switch (class) { @@ -110,16 +111,21 @@ SYSCALL_DEFINE3(ioprio_set, int, which, int, who, int, ioprio) } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); break; case IOPRIO_WHO_USER: + uid = make_kuid(current_user_ns(), who); + if (!uid_valid(uid)) + break; if (!who) user = current_user(); else - user = find_user(who); + user = find_user(uid); if (!user) break; do_each_thread(g, p) { - if (__task_cred(p)->uid != who) + const struct cred *tcred = __task_cred(p); + kuid_t tcred_uid = make_kuid(tcred->user_ns, tcred->uid); + if (!uid_eq(tcred_uid, uid)) continue; ret = set_task_ioprio(p, ioprio); if (ret) @@ -174,6 +180,7 @@ SYSCALL_DEFINE2(ioprio_get, int, which, int, who) struct task_struct *g, *p; struct user_struct *user; struct pid *pgrp; + kuid_t uid; int ret = -ESRCH; int tmpio; @@ -203,16 +210,19 @@ SYSCALL_DEFINE2(ioprio_get, int, which, int, who) } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); break; case IOPRIO_WHO_USER: + uid = make_kuid(current_user_ns(), who); if (!who) user = current_user(); else - user = find_user(who); + user = find_user(uid); if (!user) break; do_each_thread(g, p) { - if (__task_cred(p)->uid != user->uid) + const struct cred *tcred = __task_cred(p); + kuid_t tcred_uid = make_kuid(tcred->user_ns, tcred->uid); + if (!uid_eq(tcred_uid, user->uid)) continue; tmpio = get_task_ioprio(p); if (tmpio < 0) diff --git a/include/linux/sched.h b/include/linux/sched.h index 6867ae9..5fdc1eb 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -90,6 +90,7 @@ struct sched_param { #include #include #include +#include #include @@ -728,8 +729,7 @@ struct user_struct { /* Hash table maintenance information */ struct hlist_node uidhash_node; - uid_t uid; - struct user_namespace *_user_ns; /* Don't use will be removed soon */ + kuid_t uid; #ifdef CONFIG_PERF_EVENTS atomic_long_t locked_vm; @@ -738,7 +738,7 @@ struct user_struct { extern int uids_sysfs_init(void); -extern struct user_struct *find_user(uid_t); +extern struct user_struct *find_user(kuid_t); extern struct user_struct root_user; #define INIT_USER (&root_user) @@ -2177,7 +2177,7 @@ extern struct task_struct *find_task_by_pid_ns(pid_t nr, extern void __set_special_pids(struct pid *pid); /* per-UID process charging. */ -extern struct user_struct * alloc_uid(struct user_namespace *, uid_t); +extern struct user_struct * alloc_uid(kuid_t); static inline struct user_struct *get_uid(struct user_struct *u) { atomic_inc(&u->__count); diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h index dc2d85a..d767508 100644 --- a/include/linux/user_namespace.h +++ b/include/linux/user_namespace.h @@ -6,12 +6,8 @@ #include #include -#define UIDHASH_BITS (CONFIG_BASE_SMALL ? 3 : 7) -#define UIDHASH_SZ (1 << UIDHASH_BITS) - struct user_namespace { struct kref kref; - struct hlist_head uidhash_table[UIDHASH_SZ]; struct user_namespace *parent; struct user_struct *creator; struct work_struct destroyer; diff --git a/kernel/sys.c b/kernel/sys.c index 7185241..f0c43b4 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -175,6 +175,8 @@ SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval) const struct cred *cred = current_cred(); int error = -EINVAL; struct pid *pgrp; + kuid_t cred_uid; + kuid_t uid; if (which > PRIO_USER || which < PRIO_PROCESS) goto out; @@ -207,18 +209,22 @@ SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval) } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); break; case PRIO_USER: + cred_uid = make_kuid(cred->user_ns, cred->uid); + uid = make_kuid(cred->user_ns, who); user = cred->user; if (!who) - who = cred->uid; - else if ((who != cred->uid) && - !(user = find_user(who))) + uid = cred_uid; + else if (!uid_eq(uid, cred_uid) && + !(user = find_user(uid))) goto out_unlock; /* No processes for this user */ do_each_thread(g, p) { - if (__task_cred(p)->uid == who) + const struct cred *tcred = __task_cred(p); + kuid_t tcred_uid = make_kuid(tcred->user_ns, tcred->uid); + if (uid_eq(tcred_uid, uid)) error = set_one_prio(p, niceval, error); } while_each_thread(g, p); - if (who != cred->uid) + if (!uid_eq(uid, cred_uid)) free_uid(user); /* For find_user() */ break; } @@ -242,6 +248,8 @@ SYSCALL_DEFINE2(getpriority, int, which, int, who) const struct cred *cred = current_cred(); long niceval, retval = -ESRCH; struct pid *pgrp; + kuid_t cred_uid; + kuid_t uid; if (which > PRIO_USER || which < PRIO_PROCESS) return -EINVAL; @@ -272,21 +280,25 @@ SYSCALL_DEFINE2(getpriority, int, which, int, who) } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); break; case PRIO_USER: + cred_uid = make_kuid(cred->user_ns, cred->uid); + uid = make_kuid(cred->user_ns, who); user = cred->user; if (!who) - who = cred->uid; - else if ((who != cred->uid) && - !(user = find_user(who))) + uid = cred_uid; + else if (!uid_eq(uid, cred_uid) && + !(user = find_user(uid))) goto out_unlock; /* No processes for this user */ do_each_thread(g, p) { - if (__task_cred(p)->uid == who) { + const struct cred *tcred = __task_cred(p); + kuid_t tcred_uid = make_kuid(tcred->user_ns, tcred->uid); + if (uid_eq(tcred_uid, uid)) { niceval = 20 - task_nice(p); if (niceval > retval) retval = niceval; } } while_each_thread(g, p); - if (who != cred->uid) + if (!uid_eq(uid, cred_uid)) free_uid(user); /* for find_user() */ break; } @@ -629,7 +641,7 @@ static int set_user(struct cred *new) { struct user_struct *new_user; - new_user = alloc_uid(current_user_ns(), new->uid); + new_user = alloc_uid(make_kuid(new->user_ns, new->uid)); if (!new_user) return -EAGAIN; diff --git a/kernel/user.c b/kernel/user.c index d65fec0..025077e 100644 --- a/kernel/user.c +++ b/kernel/user.c @@ -34,11 +34,14 @@ EXPORT_SYMBOL_GPL(init_user_ns); * when changing user ID's (ie setuid() and friends). */ +#define UIDHASH_BITS (CONFIG_BASE_SMALL ? 3 : 7) +#define UIDHASH_SZ (1 << UIDHASH_BITS) #define UIDHASH_MASK (UIDHASH_SZ - 1) #define __uidhashfn(uid) (((uid >> UIDHASH_BITS) + uid) & UIDHASH_MASK) -#define uidhashentry(ns, uid) ((ns)->uidhash_table + __uidhashfn((uid))) +#define uidhashentry(uid) (uidhash_table + __uidhashfn((__kuid_val(uid)))) static struct kmem_cache *uid_cachep; +struct hlist_head uidhash_table[UIDHASH_SZ]; /* * The uidhash_lock is mostly taken from process context, but it is @@ -58,7 +61,7 @@ struct user_struct root_user = { .files = ATOMIC_INIT(0), .sigpending = ATOMIC_INIT(0), .locked_shm = 0, - ._user_ns = &init_user_ns, + .uid = GLOBAL_ROOT_UID, }; /* @@ -72,16 +75,15 @@ static void uid_hash_insert(struct user_struct *up, struct hlist_head *hashent) static void uid_hash_remove(struct user_struct *up) { hlist_del_init(&up->uidhash_node); - put_user_ns(up->_user_ns); /* It is safe to free the uid hash table now */ } -static struct user_struct *uid_hash_find(uid_t uid, struct hlist_head *hashent) +static struct user_struct *uid_hash_find(kuid_t uid, struct hlist_head *hashent) { struct user_struct *user; struct hlist_node *h; hlist_for_each_entry(user, h, hashent, uidhash_node) { - if (user->uid == uid) { + if (uid_eq(user->uid, uid)) { atomic_inc(&user->__count); return user; } @@ -110,14 +112,13 @@ static void free_user(struct user_struct *up, unsigned long flags) * * If the user_struct could not be found, return NULL. */ -struct user_struct *find_user(uid_t uid) +struct user_struct *find_user(kuid_t uid) { struct user_struct *ret; unsigned long flags; - struct user_namespace *ns = current_user_ns(); spin_lock_irqsave(&uidhash_lock, flags); - ret = uid_hash_find(uid, uidhashentry(ns, uid)); + ret = uid_hash_find(uid, uidhashentry(uid)); spin_unlock_irqrestore(&uidhash_lock, flags); return ret; } @@ -136,9 +137,9 @@ void free_uid(struct user_struct *up) local_irq_restore(flags); } -struct user_struct *alloc_uid(struct user_namespace *ns, uid_t uid) +struct user_struct *alloc_uid(kuid_t uid) { - struct hlist_head *hashent = uidhashentry(ns, uid); + struct hlist_head *hashent = uidhashentry(uid); struct user_struct *up, *new; spin_lock_irq(&uidhash_lock); @@ -153,8 +154,6 @@ struct user_struct *alloc_uid(struct user_namespace *ns, uid_t uid) new->uid = uid; atomic_set(&new->__count, 1); - new->_user_ns = get_user_ns(ns); - /* * Before adding this, check whether we raced * on adding the same user already.. @@ -162,7 +161,6 @@ struct user_struct *alloc_uid(struct user_namespace *ns, uid_t uid) spin_lock_irq(&uidhash_lock); up = uid_hash_find(uid, hashent); if (up) { - put_user_ns(ns); key_put(new->uid_keyring); key_put(new->session_keyring); kmem_cache_free(uid_cachep, new); @@ -187,11 +185,11 @@ static int __init uid_cache_init(void) 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); for(n = 0; n < UIDHASH_SZ; ++n) - INIT_HLIST_HEAD(init_user_ns.uidhash_table + n); + INIT_HLIST_HEAD(uidhash_table + n); /* Insert the root user immediately (init already runs as root) */ spin_lock_irq(&uidhash_lock); - uid_hash_insert(&root_user, uidhashentry(&init_user_ns, 0)); + uid_hash_insert(&root_user, uidhashentry(GLOBAL_ROOT_UID)); spin_unlock_irq(&uidhash_lock); return 0; diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c index e216e1e..898e973 100644 --- a/kernel/user_namespace.c +++ b/kernel/user_namespace.c @@ -27,7 +27,6 @@ int create_user_ns(struct cred *new) { struct user_namespace *ns, *parent_ns = new->user_ns; struct user_struct *root_user; - int n; ns = kmem_cache_alloc(user_ns_cachep, GFP_KERNEL); if (!ns) @@ -35,11 +34,8 @@ int create_user_ns(struct cred *new) kref_init(&ns->kref); - for (n = 0; n < UIDHASH_SZ; ++n) - INIT_HLIST_HEAD(ns->uidhash_table + n); - /* Alloc new root user. */ - root_user = alloc_uid(ns, 0); + root_user = alloc_uid(make_kuid(ns, 0)); if (!root_user) { kmem_cache_free(user_ns_cachep, ns); return -ENOMEM; -- 1.7.2.5 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755775Ab2DHFUE (ORCPT ); Sun, 8 Apr 2012 01:20:04 -0400 Received: from out01.mta.xmission.com ([166.70.13.231]:51485 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752652Ab2DHFMU (ORCPT ); Sun, 8 Apr 2012 01:12:20 -0400 From: "\"Eric W. Beiderman" To: Cc: , , Linux Containers , Andrew Morton , Linus Torvalds , Al Viro , Cyrill Gorcunov , "Eric W. Biederman" Date: Sat, 7 Apr 2012 22:15:11 -0700 Message-Id: <1333862139-31737-15-git-send-email-ebiederm@xmission.com> X-Mailer: git-send-email 1.7.2.5 In-Reply-To: References: X-XM-SPF: eid=;;;mid=;;;hst=in02.mta.xmission.com;;;ip=98.207.153.68;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX18+M1RAkW1R86+xzihs0WlrPiuwnD5/6ws= X-SA-Exim-Connect-IP: 98.207.153.68 X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-Report: * 1.1 FH_FROMEML_NOTLD E-mail address doesn't have TLD (.com, etc.) * 1.5 XMNoVowels Alpha-numberic number with no vowels * 0.1 XMSubLong Long Subject * 0.0 T_TM2_M_HEADER_IN_MSG BODY: T_TM2_M_HEADER_IN_MSG * -0.0 BAYES_40 BODY: Bayes spam probability is 20 to 40% * [score: 0.3281] * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa02 1397; Body=1 Fuz1=1 Fuz2=1] * 0.0 T_XMDrugObfuBody_14 obfuscated drug references * 0.0 T_TooManySym_01 4+ unique symbols in subject * 0.0 T_TooManySym_02 5+ unique symbols in subject * 0.4 UNTRUSTED_Relay Comes from a non-trusted relay X-Spam-DCC: XMission; sa02 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: ***; X-Spam-Relay-Country: ** Subject: [PATCH 15/43] userns: Disassociate user_struct from the user_namespace. X-Spam-Flag: No X-SA-Exim-Version: 4.2.1 (built Fri, 06 Aug 2010 16:31:04 -0600) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Eric W. Biederman Modify alloc_uid to take a kuid and make the user hash table global. Stop holding a reference to the user namespace in struct user_struct. This simplifies the code and makes the per user accounting not care about which user namespace a uid happens to appear in. Acked-by: Serge Hallyn Signed-off-by: Eric W. Biederman --- fs/ioprio.c | 18 ++++++++++++++---- include/linux/sched.h | 8 ++++---- include/linux/user_namespace.h | 4 ---- kernel/sys.c | 34 +++++++++++++++++++++++----------- kernel/user.c | 28 +++++++++++++--------------- kernel/user_namespace.c | 6 +----- 6 files changed, 55 insertions(+), 43 deletions(-) diff --git a/fs/ioprio.c b/fs/ioprio.c index 0f1b951..8e35e96 100644 --- a/fs/ioprio.c +++ b/fs/ioprio.c @@ -65,6 +65,7 @@ SYSCALL_DEFINE3(ioprio_set, int, which, int, who, int, ioprio) struct task_struct *p, *g; struct user_struct *user; struct pid *pgrp; + kuid_t uid; int ret; switch (class) { @@ -110,16 +111,21 @@ SYSCALL_DEFINE3(ioprio_set, int, which, int, who, int, ioprio) } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); break; case IOPRIO_WHO_USER: + uid = make_kuid(current_user_ns(), who); + if (!uid_valid(uid)) + break; if (!who) user = current_user(); else - user = find_user(who); + user = find_user(uid); if (!user) break; do_each_thread(g, p) { - if (__task_cred(p)->uid != who) + const struct cred *tcred = __task_cred(p); + kuid_t tcred_uid = make_kuid(tcred->user_ns, tcred->uid); + if (!uid_eq(tcred_uid, uid)) continue; ret = set_task_ioprio(p, ioprio); if (ret) @@ -174,6 +180,7 @@ SYSCALL_DEFINE2(ioprio_get, int, which, int, who) struct task_struct *g, *p; struct user_struct *user; struct pid *pgrp; + kuid_t uid; int ret = -ESRCH; int tmpio; @@ -203,16 +210,19 @@ SYSCALL_DEFINE2(ioprio_get, int, which, int, who) } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); break; case IOPRIO_WHO_USER: + uid = make_kuid(current_user_ns(), who); if (!who) user = current_user(); else - user = find_user(who); + user = find_user(uid); if (!user) break; do_each_thread(g, p) { - if (__task_cred(p)->uid != user->uid) + const struct cred *tcred = __task_cred(p); + kuid_t tcred_uid = make_kuid(tcred->user_ns, tcred->uid); + if (!uid_eq(tcred_uid, user->uid)) continue; tmpio = get_task_ioprio(p); if (tmpio < 0) diff --git a/include/linux/sched.h b/include/linux/sched.h index 6867ae9..5fdc1eb 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -90,6 +90,7 @@ struct sched_param { #include #include #include +#include #include @@ -728,8 +729,7 @@ struct user_struct { /* Hash table maintenance information */ struct hlist_node uidhash_node; - uid_t uid; - struct user_namespace *_user_ns; /* Don't use will be removed soon */ + kuid_t uid; #ifdef CONFIG_PERF_EVENTS atomic_long_t locked_vm; @@ -738,7 +738,7 @@ struct user_struct { extern int uids_sysfs_init(void); -extern struct user_struct *find_user(uid_t); +extern struct user_struct *find_user(kuid_t); extern struct user_struct root_user; #define INIT_USER (&root_user) @@ -2177,7 +2177,7 @@ extern struct task_struct *find_task_by_pid_ns(pid_t nr, extern void __set_special_pids(struct pid *pid); /* per-UID process charging. */ -extern struct user_struct * alloc_uid(struct user_namespace *, uid_t); +extern struct user_struct * alloc_uid(kuid_t); static inline struct user_struct *get_uid(struct user_struct *u) { atomic_inc(&u->__count); diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h index dc2d85a..d767508 100644 --- a/include/linux/user_namespace.h +++ b/include/linux/user_namespace.h @@ -6,12 +6,8 @@ #include #include -#define UIDHASH_BITS (CONFIG_BASE_SMALL ? 3 : 7) -#define UIDHASH_SZ (1 << UIDHASH_BITS) - struct user_namespace { struct kref kref; - struct hlist_head uidhash_table[UIDHASH_SZ]; struct user_namespace *parent; struct user_struct *creator; struct work_struct destroyer; diff --git a/kernel/sys.c b/kernel/sys.c index 7185241..f0c43b4 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -175,6 +175,8 @@ SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval) const struct cred *cred = current_cred(); int error = -EINVAL; struct pid *pgrp; + kuid_t cred_uid; + kuid_t uid; if (which > PRIO_USER || which < PRIO_PROCESS) goto out; @@ -207,18 +209,22 @@ SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval) } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); break; case PRIO_USER: + cred_uid = make_kuid(cred->user_ns, cred->uid); + uid = make_kuid(cred->user_ns, who); user = cred->user; if (!who) - who = cred->uid; - else if ((who != cred->uid) && - !(user = find_user(who))) + uid = cred_uid; + else if (!uid_eq(uid, cred_uid) && + !(user = find_user(uid))) goto out_unlock; /* No processes for this user */ do_each_thread(g, p) { - if (__task_cred(p)->uid == who) + const struct cred *tcred = __task_cred(p); + kuid_t tcred_uid = make_kuid(tcred->user_ns, tcred->uid); + if (uid_eq(tcred_uid, uid)) error = set_one_prio(p, niceval, error); } while_each_thread(g, p); - if (who != cred->uid) + if (!uid_eq(uid, cred_uid)) free_uid(user); /* For find_user() */ break; } @@ -242,6 +248,8 @@ SYSCALL_DEFINE2(getpriority, int, which, int, who) const struct cred *cred = current_cred(); long niceval, retval = -ESRCH; struct pid *pgrp; + kuid_t cred_uid; + kuid_t uid; if (which > PRIO_USER || which < PRIO_PROCESS) return -EINVAL; @@ -272,21 +280,25 @@ SYSCALL_DEFINE2(getpriority, int, which, int, who) } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); break; case PRIO_USER: + cred_uid = make_kuid(cred->user_ns, cred->uid); + uid = make_kuid(cred->user_ns, who); user = cred->user; if (!who) - who = cred->uid; - else if ((who != cred->uid) && - !(user = find_user(who))) + uid = cred_uid; + else if (!uid_eq(uid, cred_uid) && + !(user = find_user(uid))) goto out_unlock; /* No processes for this user */ do_each_thread(g, p) { - if (__task_cred(p)->uid == who) { + const struct cred *tcred = __task_cred(p); + kuid_t tcred_uid = make_kuid(tcred->user_ns, tcred->uid); + if (uid_eq(tcred_uid, uid)) { niceval = 20 - task_nice(p); if (niceval > retval) retval = niceval; } } while_each_thread(g, p); - if (who != cred->uid) + if (!uid_eq(uid, cred_uid)) free_uid(user); /* for find_user() */ break; } @@ -629,7 +641,7 @@ static int set_user(struct cred *new) { struct user_struct *new_user; - new_user = alloc_uid(current_user_ns(), new->uid); + new_user = alloc_uid(make_kuid(new->user_ns, new->uid)); if (!new_user) return -EAGAIN; diff --git a/kernel/user.c b/kernel/user.c index d65fec0..025077e 100644 --- a/kernel/user.c +++ b/kernel/user.c @@ -34,11 +34,14 @@ EXPORT_SYMBOL_GPL(init_user_ns); * when changing user ID's (ie setuid() and friends). */ +#define UIDHASH_BITS (CONFIG_BASE_SMALL ? 3 : 7) +#define UIDHASH_SZ (1 << UIDHASH_BITS) #define UIDHASH_MASK (UIDHASH_SZ - 1) #define __uidhashfn(uid) (((uid >> UIDHASH_BITS) + uid) & UIDHASH_MASK) -#define uidhashentry(ns, uid) ((ns)->uidhash_table + __uidhashfn((uid))) +#define uidhashentry(uid) (uidhash_table + __uidhashfn((__kuid_val(uid)))) static struct kmem_cache *uid_cachep; +struct hlist_head uidhash_table[UIDHASH_SZ]; /* * The uidhash_lock is mostly taken from process context, but it is @@ -58,7 +61,7 @@ struct user_struct root_user = { .files = ATOMIC_INIT(0), .sigpending = ATOMIC_INIT(0), .locked_shm = 0, - ._user_ns = &init_user_ns, + .uid = GLOBAL_ROOT_UID, }; /* @@ -72,16 +75,15 @@ static void uid_hash_insert(struct user_struct *up, struct hlist_head *hashent) static void uid_hash_remove(struct user_struct *up) { hlist_del_init(&up->uidhash_node); - put_user_ns(up->_user_ns); /* It is safe to free the uid hash table now */ } -static struct user_struct *uid_hash_find(uid_t uid, struct hlist_head *hashent) +static struct user_struct *uid_hash_find(kuid_t uid, struct hlist_head *hashent) { struct user_struct *user; struct hlist_node *h; hlist_for_each_entry(user, h, hashent, uidhash_node) { - if (user->uid == uid) { + if (uid_eq(user->uid, uid)) { atomic_inc(&user->__count); return user; } @@ -110,14 +112,13 @@ static void free_user(struct user_struct *up, unsigned long flags) * * If the user_struct could not be found, return NULL. */ -struct user_struct *find_user(uid_t uid) +struct user_struct *find_user(kuid_t uid) { struct user_struct *ret; unsigned long flags; - struct user_namespace *ns = current_user_ns(); spin_lock_irqsave(&uidhash_lock, flags); - ret = uid_hash_find(uid, uidhashentry(ns, uid)); + ret = uid_hash_find(uid, uidhashentry(uid)); spin_unlock_irqrestore(&uidhash_lock, flags); return ret; } @@ -136,9 +137,9 @@ void free_uid(struct user_struct *up) local_irq_restore(flags); } -struct user_struct *alloc_uid(struct user_namespace *ns, uid_t uid) +struct user_struct *alloc_uid(kuid_t uid) { - struct hlist_head *hashent = uidhashentry(ns, uid); + struct hlist_head *hashent = uidhashentry(uid); struct user_struct *up, *new; spin_lock_irq(&uidhash_lock); @@ -153,8 +154,6 @@ struct user_struct *alloc_uid(struct user_namespace *ns, uid_t uid) new->uid = uid; atomic_set(&new->__count, 1); - new->_user_ns = get_user_ns(ns); - /* * Before adding this, check whether we raced * on adding the same user already.. @@ -162,7 +161,6 @@ struct user_struct *alloc_uid(struct user_namespace *ns, uid_t uid) spin_lock_irq(&uidhash_lock); up = uid_hash_find(uid, hashent); if (up) { - put_user_ns(ns); key_put(new->uid_keyring); key_put(new->session_keyring); kmem_cache_free(uid_cachep, new); @@ -187,11 +185,11 @@ static int __init uid_cache_init(void) 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); for(n = 0; n < UIDHASH_SZ; ++n) - INIT_HLIST_HEAD(init_user_ns.uidhash_table + n); + INIT_HLIST_HEAD(uidhash_table + n); /* Insert the root user immediately (init already runs as root) */ spin_lock_irq(&uidhash_lock); - uid_hash_insert(&root_user, uidhashentry(&init_user_ns, 0)); + uid_hash_insert(&root_user, uidhashentry(GLOBAL_ROOT_UID)); spin_unlock_irq(&uidhash_lock); return 0; diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c index e216e1e..898e973 100644 --- a/kernel/user_namespace.c +++ b/kernel/user_namespace.c @@ -27,7 +27,6 @@ int create_user_ns(struct cred *new) { struct user_namespace *ns, *parent_ns = new->user_ns; struct user_struct *root_user; - int n; ns = kmem_cache_alloc(user_ns_cachep, GFP_KERNEL); if (!ns) @@ -35,11 +34,8 @@ int create_user_ns(struct cred *new) kref_init(&ns->kref); - for (n = 0; n < UIDHASH_SZ; ++n) - INIT_HLIST_HEAD(ns->uidhash_table + n); - /* Alloc new root user. */ - root_user = alloc_uid(ns, 0); + root_user = alloc_uid(make_kuid(ns, 0)); if (!root_user) { kmem_cache_free(user_ns_cachep, ns); return -ENOMEM; -- 1.7.2.5 From mboxrd@z Thu Jan 1 00:00:00 1970 From: "\"Eric W. Beiderman" Subject: [PATCH 15/43] userns: Disassociate user_struct from the user_namespace. Date: Sat, 7 Apr 2012 22:15:11 -0700 Message-ID: <1333862139-31737-15-git-send-email-ebiederm@xmission.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Linux Containers , Cyrill Gorcunov , linux-security-module-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Al Viro , linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Andrew Morton , Linus Torvalds , "Eric W. Biederman" To: Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org List-Id: linux-fsdevel.vger.kernel.org From: Eric W. Biederman Modify alloc_uid to take a kuid and make the user hash table global. Stop holding a reference to the user namespace in struct user_struct. This simplifies the code and makes the per user accounting not care about which user namespace a uid happens to appear in. Acked-by: Serge Hallyn Signed-off-by: Eric W. Biederman --- fs/ioprio.c | 18 ++++++++++++++---- include/linux/sched.h | 8 ++++---- include/linux/user_namespace.h | 4 ---- kernel/sys.c | 34 +++++++++++++++++++++++----------- kernel/user.c | 28 +++++++++++++--------------- kernel/user_namespace.c | 6 +----- 6 files changed, 55 insertions(+), 43 deletions(-) diff --git a/fs/ioprio.c b/fs/ioprio.c index 0f1b951..8e35e96 100644 --- a/fs/ioprio.c +++ b/fs/ioprio.c @@ -65,6 +65,7 @@ SYSCALL_DEFINE3(ioprio_set, int, which, int, who, int, ioprio) struct task_struct *p, *g; struct user_struct *user; struct pid *pgrp; + kuid_t uid; int ret; switch (class) { @@ -110,16 +111,21 @@ SYSCALL_DEFINE3(ioprio_set, int, which, int, who, int, ioprio) } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); break; case IOPRIO_WHO_USER: + uid = make_kuid(current_user_ns(), who); + if (!uid_valid(uid)) + break; if (!who) user = current_user(); else - user = find_user(who); + user = find_user(uid); if (!user) break; do_each_thread(g, p) { - if (__task_cred(p)->uid != who) + const struct cred *tcred = __task_cred(p); + kuid_t tcred_uid = make_kuid(tcred->user_ns, tcred->uid); + if (!uid_eq(tcred_uid, uid)) continue; ret = set_task_ioprio(p, ioprio); if (ret) @@ -174,6 +180,7 @@ SYSCALL_DEFINE2(ioprio_get, int, which, int, who) struct task_struct *g, *p; struct user_struct *user; struct pid *pgrp; + kuid_t uid; int ret = -ESRCH; int tmpio; @@ -203,16 +210,19 @@ SYSCALL_DEFINE2(ioprio_get, int, which, int, who) } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); break; case IOPRIO_WHO_USER: + uid = make_kuid(current_user_ns(), who); if (!who) user = current_user(); else - user = find_user(who); + user = find_user(uid); if (!user) break; do_each_thread(g, p) { - if (__task_cred(p)->uid != user->uid) + const struct cred *tcred = __task_cred(p); + kuid_t tcred_uid = make_kuid(tcred->user_ns, tcred->uid); + if (!uid_eq(tcred_uid, user->uid)) continue; tmpio = get_task_ioprio(p); if (tmpio < 0) diff --git a/include/linux/sched.h b/include/linux/sched.h index 6867ae9..5fdc1eb 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -90,6 +90,7 @@ struct sched_param { #include #include #include +#include #include @@ -728,8 +729,7 @@ struct user_struct { /* Hash table maintenance information */ struct hlist_node uidhash_node; - uid_t uid; - struct user_namespace *_user_ns; /* Don't use will be removed soon */ + kuid_t uid; #ifdef CONFIG_PERF_EVENTS atomic_long_t locked_vm; @@ -738,7 +738,7 @@ struct user_struct { extern int uids_sysfs_init(void); -extern struct user_struct *find_user(uid_t); +extern struct user_struct *find_user(kuid_t); extern struct user_struct root_user; #define INIT_USER (&root_user) @@ -2177,7 +2177,7 @@ extern struct task_struct *find_task_by_pid_ns(pid_t nr, extern void __set_special_pids(struct pid *pid); /* per-UID process charging. */ -extern struct user_struct * alloc_uid(struct user_namespace *, uid_t); +extern struct user_struct * alloc_uid(kuid_t); static inline struct user_struct *get_uid(struct user_struct *u) { atomic_inc(&u->__count); diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h index dc2d85a..d767508 100644 --- a/include/linux/user_namespace.h +++ b/include/linux/user_namespace.h @@ -6,12 +6,8 @@ #include #include -#define UIDHASH_BITS (CONFIG_BASE_SMALL ? 3 : 7) -#define UIDHASH_SZ (1 << UIDHASH_BITS) - struct user_namespace { struct kref kref; - struct hlist_head uidhash_table[UIDHASH_SZ]; struct user_namespace *parent; struct user_struct *creator; struct work_struct destroyer; diff --git a/kernel/sys.c b/kernel/sys.c index 7185241..f0c43b4 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -175,6 +175,8 @@ SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval) const struct cred *cred = current_cred(); int error = -EINVAL; struct pid *pgrp; + kuid_t cred_uid; + kuid_t uid; if (which > PRIO_USER || which < PRIO_PROCESS) goto out; @@ -207,18 +209,22 @@ SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval) } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); break; case PRIO_USER: + cred_uid = make_kuid(cred->user_ns, cred->uid); + uid = make_kuid(cred->user_ns, who); user = cred->user; if (!who) - who = cred->uid; - else if ((who != cred->uid) && - !(user = find_user(who))) + uid = cred_uid; + else if (!uid_eq(uid, cred_uid) && + !(user = find_user(uid))) goto out_unlock; /* No processes for this user */ do_each_thread(g, p) { - if (__task_cred(p)->uid == who) + const struct cred *tcred = __task_cred(p); + kuid_t tcred_uid = make_kuid(tcred->user_ns, tcred->uid); + if (uid_eq(tcred_uid, uid)) error = set_one_prio(p, niceval, error); } while_each_thread(g, p); - if (who != cred->uid) + if (!uid_eq(uid, cred_uid)) free_uid(user); /* For find_user() */ break; } @@ -242,6 +248,8 @@ SYSCALL_DEFINE2(getpriority, int, which, int, who) const struct cred *cred = current_cred(); long niceval, retval = -ESRCH; struct pid *pgrp; + kuid_t cred_uid; + kuid_t uid; if (which > PRIO_USER || which < PRIO_PROCESS) return -EINVAL; @@ -272,21 +280,25 @@ SYSCALL_DEFINE2(getpriority, int, which, int, who) } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); break; case PRIO_USER: + cred_uid = make_kuid(cred->user_ns, cred->uid); + uid = make_kuid(cred->user_ns, who); user = cred->user; if (!who) - who = cred->uid; - else if ((who != cred->uid) && - !(user = find_user(who))) + uid = cred_uid; + else if (!uid_eq(uid, cred_uid) && + !(user = find_user(uid))) goto out_unlock; /* No processes for this user */ do_each_thread(g, p) { - if (__task_cred(p)->uid == who) { + const struct cred *tcred = __task_cred(p); + kuid_t tcred_uid = make_kuid(tcred->user_ns, tcred->uid); + if (uid_eq(tcred_uid, uid)) { niceval = 20 - task_nice(p); if (niceval > retval) retval = niceval; } } while_each_thread(g, p); - if (who != cred->uid) + if (!uid_eq(uid, cred_uid)) free_uid(user); /* for find_user() */ break; } @@ -629,7 +641,7 @@ static int set_user(struct cred *new) { struct user_struct *new_user; - new_user = alloc_uid(current_user_ns(), new->uid); + new_user = alloc_uid(make_kuid(new->user_ns, new->uid)); if (!new_user) return -EAGAIN; diff --git a/kernel/user.c b/kernel/user.c index d65fec0..025077e 100644 --- a/kernel/user.c +++ b/kernel/user.c @@ -34,11 +34,14 @@ EXPORT_SYMBOL_GPL(init_user_ns); * when changing user ID's (ie setuid() and friends). */ +#define UIDHASH_BITS (CONFIG_BASE_SMALL ? 3 : 7) +#define UIDHASH_SZ (1 << UIDHASH_BITS) #define UIDHASH_MASK (UIDHASH_SZ - 1) #define __uidhashfn(uid) (((uid >> UIDHASH_BITS) + uid) & UIDHASH_MASK) -#define uidhashentry(ns, uid) ((ns)->uidhash_table + __uidhashfn((uid))) +#define uidhashentry(uid) (uidhash_table + __uidhashfn((__kuid_val(uid)))) static struct kmem_cache *uid_cachep; +struct hlist_head uidhash_table[UIDHASH_SZ]; /* * The uidhash_lock is mostly taken from process context, but it is @@ -58,7 +61,7 @@ struct user_struct root_user = { .files = ATOMIC_INIT(0), .sigpending = ATOMIC_INIT(0), .locked_shm = 0, - ._user_ns = &init_user_ns, + .uid = GLOBAL_ROOT_UID, }; /* @@ -72,16 +75,15 @@ static void uid_hash_insert(struct user_struct *up, struct hlist_head *hashent) static void uid_hash_remove(struct user_struct *up) { hlist_del_init(&up->uidhash_node); - put_user_ns(up->_user_ns); /* It is safe to free the uid hash table now */ } -static struct user_struct *uid_hash_find(uid_t uid, struct hlist_head *hashent) +static struct user_struct *uid_hash_find(kuid_t uid, struct hlist_head *hashent) { struct user_struct *user; struct hlist_node *h; hlist_for_each_entry(user, h, hashent, uidhash_node) { - if (user->uid == uid) { + if (uid_eq(user->uid, uid)) { atomic_inc(&user->__count); return user; } @@ -110,14 +112,13 @@ static void free_user(struct user_struct *up, unsigned long flags) * * If the user_struct could not be found, return NULL. */ -struct user_struct *find_user(uid_t uid) +struct user_struct *find_user(kuid_t uid) { struct user_struct *ret; unsigned long flags; - struct user_namespace *ns = current_user_ns(); spin_lock_irqsave(&uidhash_lock, flags); - ret = uid_hash_find(uid, uidhashentry(ns, uid)); + ret = uid_hash_find(uid, uidhashentry(uid)); spin_unlock_irqrestore(&uidhash_lock, flags); return ret; } @@ -136,9 +137,9 @@ void free_uid(struct user_struct *up) local_irq_restore(flags); } -struct user_struct *alloc_uid(struct user_namespace *ns, uid_t uid) +struct user_struct *alloc_uid(kuid_t uid) { - struct hlist_head *hashent = uidhashentry(ns, uid); + struct hlist_head *hashent = uidhashentry(uid); struct user_struct *up, *new; spin_lock_irq(&uidhash_lock); @@ -153,8 +154,6 @@ struct user_struct *alloc_uid(struct user_namespace *ns, uid_t uid) new->uid = uid; atomic_set(&new->__count, 1); - new->_user_ns = get_user_ns(ns); - /* * Before adding this, check whether we raced * on adding the same user already.. @@ -162,7 +161,6 @@ struct user_struct *alloc_uid(struct user_namespace *ns, uid_t uid) spin_lock_irq(&uidhash_lock); up = uid_hash_find(uid, hashent); if (up) { - put_user_ns(ns); key_put(new->uid_keyring); key_put(new->session_keyring); kmem_cache_free(uid_cachep, new); @@ -187,11 +185,11 @@ static int __init uid_cache_init(void) 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); for(n = 0; n < UIDHASH_SZ; ++n) - INIT_HLIST_HEAD(init_user_ns.uidhash_table + n); + INIT_HLIST_HEAD(uidhash_table + n); /* Insert the root user immediately (init already runs as root) */ spin_lock_irq(&uidhash_lock); - uid_hash_insert(&root_user, uidhashentry(&init_user_ns, 0)); + uid_hash_insert(&root_user, uidhashentry(GLOBAL_ROOT_UID)); spin_unlock_irq(&uidhash_lock); return 0; diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c index e216e1e..898e973 100644 --- a/kernel/user_namespace.c +++ b/kernel/user_namespace.c @@ -27,7 +27,6 @@ int create_user_ns(struct cred *new) { struct user_namespace *ns, *parent_ns = new->user_ns; struct user_struct *root_user; - int n; ns = kmem_cache_alloc(user_ns_cachep, GFP_KERNEL); if (!ns) @@ -35,11 +34,8 @@ int create_user_ns(struct cred *new) kref_init(&ns->kref); - for (n = 0; n < UIDHASH_SZ; ++n) - INIT_HLIST_HEAD(ns->uidhash_table + n); - /* Alloc new root user. */ - root_user = alloc_uid(ns, 0); + root_user = alloc_uid(make_kuid(ns, 0)); if (!root_user) { kmem_cache_free(user_ns_cachep, ns); return -ENOMEM; -- 1.7.2.5