diff options
author | Steven Rostedt (Red Hat) <rostedt@goodmis.org> | 2015-01-16 14:19:36 -0500 |
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committer | Steven Rostedt <rostedt@goodmis.org> | 2015-01-16 14:19:36 -0500 |
commit | 4e5f18c6209fd0172b826a4ed1d79bcf6039191d (patch) | |
tree | 1c341208509931d18f811b12f4782ec89b20452d /kernel | |
parent | 7e8cf38580df94f5372f3a5b2789b8d5f6c5e7eb (diff) | |
parent | c3b70f0bbb6a883f4afa639286043d3f71fbbddf (diff) |
Merge tag 'v3.14.28' into temp
This is the 3.14.28 stable release
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/auditfilter.c | 10 | ||||
-rw-r--r-- | kernel/groups.c | 11 | ||||
-rw-r--r-- | kernel/pid.c | 2 | ||||
-rw-r--r-- | kernel/uid16.c | 2 | ||||
-rw-r--r-- | kernel/user.c | 1 | ||||
-rw-r--r-- | kernel/user_namespace.c | 125 |
6 files changed, 137 insertions, 14 deletions
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c index 92062fd6cc8c..598c1dcf26dd 100644 --- a/kernel/auditfilter.c +++ b/kernel/auditfilter.c @@ -429,6 +429,7 @@ static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data, if ((f->type == AUDIT_LOGINUID) && (f->val == AUDIT_UID_UNSET)) { f->type = AUDIT_LOGINUID_SET; f->val = 0; + entry->rule.pflags |= AUDIT_LOGINUID_LEGACY; } err = audit_field_valid(entry, f); @@ -604,6 +605,13 @@ static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule) data->buflen += data->values[i] = audit_pack_string(&bufp, krule->filterkey); break; + case AUDIT_LOGINUID_SET: + if (krule->pflags & AUDIT_LOGINUID_LEGACY && !f->val) { + data->fields[i] = AUDIT_LOGINUID; + data->values[i] = AUDIT_UID_UNSET; + break; + } + /* fallthrough if set */ default: data->values[i] = f->val; } @@ -620,6 +628,7 @@ static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b) int i; if (a->flags != b->flags || + a->pflags != b->pflags || a->listnr != b->listnr || a->action != b->action || a->field_count != b->field_count) @@ -738,6 +747,7 @@ struct audit_entry *audit_dupe_rule(struct audit_krule *old) new = &entry->rule; new->vers_ops = old->vers_ops; new->flags = old->flags; + new->pflags = old->pflags; new->listnr = old->listnr; new->action = old->action; for (i = 0; i < AUDIT_BITMASK_SIZE; i++) diff --git a/kernel/groups.c b/kernel/groups.c index 90cf1c38c8ea..67b4ba30475f 100644 --- a/kernel/groups.c +++ b/kernel/groups.c @@ -6,6 +6,7 @@ #include <linux/slab.h> #include <linux/security.h> #include <linux/syscalls.h> +#include <linux/user_namespace.h> #include <asm/uaccess.h> /* init to 2 - one for init_task, one to ensure it is never freed */ @@ -223,6 +224,14 @@ out: return i; } +bool may_setgroups(void) +{ + struct user_namespace *user_ns = current_user_ns(); + + return ns_capable(user_ns, CAP_SETGID) && + userns_may_setgroups(user_ns); +} + /* * SMP: Our groups are copy-on-write. We can set them safely * without another task interfering. @@ -233,7 +242,7 @@ SYSCALL_DEFINE2(setgroups, int, gidsetsize, gid_t __user *, grouplist) struct group_info *group_info; int retval; - if (!ns_capable(current_user_ns(), CAP_SETGID)) + if (!may_setgroups()) return -EPERM; if ((unsigned)gidsetsize > NGROUPS_MAX) return -EINVAL; diff --git a/kernel/pid.c b/kernel/pid.c index 9b9a26698144..82430c858d69 100644 --- a/kernel/pid.c +++ b/kernel/pid.c @@ -341,6 +341,8 @@ out: out_unlock: spin_unlock_irq(&pidmap_lock); + put_pid_ns(ns); + out_free: while (++i <= ns->level) free_pidmap(pid->numbers + i); diff --git a/kernel/uid16.c b/kernel/uid16.c index 602e5bbbceff..d58cc4d8f0d1 100644 --- a/kernel/uid16.c +++ b/kernel/uid16.c @@ -176,7 +176,7 @@ SYSCALL_DEFINE2(setgroups16, int, gidsetsize, old_gid_t __user *, grouplist) struct group_info *group_info; int retval; - if (!ns_capable(current_user_ns(), CAP_SETGID)) + if (!may_setgroups()) return -EPERM; if ((unsigned)gidsetsize > NGROUPS_MAX) return -EINVAL; diff --git a/kernel/user.c b/kernel/user.c index 4e1c2411b0a6..8e364b03c329 100644 --- a/kernel/user.c +++ b/kernel/user.c @@ -51,6 +51,7 @@ struct user_namespace init_user_ns = { .owner = GLOBAL_ROOT_UID, .group = GLOBAL_ROOT_GID, .proc_inum = PROC_USER_INIT_INO, + .flags = USERNS_INIT_FLAGS, #ifdef CONFIG_PERSISTENT_KEYRINGS .persistent_keyring_register_sem = __RWSEM_INITIALIZER(init_user_ns.persistent_keyring_register_sem), diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c index 80a57afd8647..153971e4798a 100644 --- a/kernel/user_namespace.c +++ b/kernel/user_namespace.c @@ -24,6 +24,7 @@ #include <linux/fs_struct.h> static struct kmem_cache *user_ns_cachep __read_mostly; +static DEFINE_MUTEX(userns_state_mutex); static bool new_idmap_permitted(const struct file *file, struct user_namespace *ns, int cap_setid, @@ -99,6 +100,11 @@ int create_user_ns(struct cred *new) ns->owner = owner; ns->group = group; + /* Inherit USERNS_SETGROUPS_ALLOWED from our parent */ + mutex_lock(&userns_state_mutex); + ns->flags = parent_ns->flags; + mutex_unlock(&userns_state_mutex); + set_cred_user_ns(new, ns); #ifdef CONFIG_PERSISTENT_KEYRINGS @@ -581,9 +587,6 @@ static bool mappings_overlap(struct uid_gid_map *new_map, struct uid_gid_extent return false; } - -static DEFINE_MUTEX(id_map_mutex); - static ssize_t map_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos, int cap_setid, @@ -600,7 +603,7 @@ static ssize_t map_write(struct file *file, const char __user *buf, ssize_t ret = -EINVAL; /* - * The id_map_mutex serializes all writes to any given map. + * The userns_state_mutex serializes all writes to any given map. * * Any map is only ever written once. * @@ -618,7 +621,7 @@ static ssize_t map_write(struct file *file, const char __user *buf, * order and smp_rmb() is guaranteed that we don't have crazy * architectures returning stale data. */ - mutex_lock(&id_map_mutex); + mutex_lock(&userns_state_mutex); ret = -EPERM; /* Only allow one successful write to the map */ @@ -745,7 +748,7 @@ static ssize_t map_write(struct file *file, const char __user *buf, *ppos = count; ret = count; out: - mutex_unlock(&id_map_mutex); + mutex_unlock(&userns_state_mutex); if (page) free_page(page); return ret; @@ -804,17 +807,21 @@ static bool new_idmap_permitted(const struct file *file, struct user_namespace *ns, int cap_setid, struct uid_gid_map *new_map) { - /* Allow mapping to your own filesystem ids */ - if ((new_map->nr_extents == 1) && (new_map->extent[0].count == 1)) { + const struct cred *cred = file->f_cred; + /* Don't allow mappings that would allow anything that wouldn't + * be allowed without the establishment of unprivileged mappings. + */ + if ((new_map->nr_extents == 1) && (new_map->extent[0].count == 1) && + uid_eq(ns->owner, cred->euid)) { u32 id = new_map->extent[0].lower_first; if (cap_setid == CAP_SETUID) { kuid_t uid = make_kuid(ns->parent, id); - if (uid_eq(uid, file->f_cred->fsuid)) + if (uid_eq(uid, cred->euid)) return true; - } - else if (cap_setid == CAP_SETGID) { + } else if (cap_setid == CAP_SETGID) { kgid_t gid = make_kgid(ns->parent, id); - if (gid_eq(gid, file->f_cred->fsgid)) + if (!(ns->flags & USERNS_SETGROUPS_ALLOWED) && + gid_eq(gid, cred->egid)) return true; } } @@ -834,6 +841,100 @@ static bool new_idmap_permitted(const struct file *file, return false; } +int proc_setgroups_show(struct seq_file *seq, void *v) +{ + struct user_namespace *ns = seq->private; + unsigned long userns_flags = ACCESS_ONCE(ns->flags); + + seq_printf(seq, "%s\n", + (userns_flags & USERNS_SETGROUPS_ALLOWED) ? + "allow" : "deny"); + return 0; +} + +ssize_t proc_setgroups_write(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct seq_file *seq = file->private_data; + struct user_namespace *ns = seq->private; + char kbuf[8], *pos; + bool setgroups_allowed; + ssize_t ret; + + /* Only allow a very narrow range of strings to be written */ + ret = -EINVAL; + if ((*ppos != 0) || (count >= sizeof(kbuf))) + goto out; + + /* What was written? */ + ret = -EFAULT; + if (copy_from_user(kbuf, buf, count)) + goto out; + kbuf[count] = '\0'; + pos = kbuf; + + /* What is being requested? */ + ret = -EINVAL; + if (strncmp(pos, "allow", 5) == 0) { + pos += 5; + setgroups_allowed = true; + } + else if (strncmp(pos, "deny", 4) == 0) { + pos += 4; + setgroups_allowed = false; + } + else + goto out; + + /* Verify there is not trailing junk on the line */ + pos = skip_spaces(pos); + if (*pos != '\0') + goto out; + + ret = -EPERM; + mutex_lock(&userns_state_mutex); + if (setgroups_allowed) { + /* Enabling setgroups after setgroups has been disabled + * is not allowed. + */ + if (!(ns->flags & USERNS_SETGROUPS_ALLOWED)) + goto out_unlock; + } else { + /* Permanently disabling setgroups after setgroups has + * been enabled by writing the gid_map is not allowed. + */ + if (ns->gid_map.nr_extents != 0) + goto out_unlock; + ns->flags &= ~USERNS_SETGROUPS_ALLOWED; + } + mutex_unlock(&userns_state_mutex); + + /* Report a successful write */ + *ppos = count; + ret = count; +out: + return ret; +out_unlock: + mutex_unlock(&userns_state_mutex); + goto out; +} + +bool userns_may_setgroups(const struct user_namespace *ns) +{ + bool allowed; + + mutex_lock(&userns_state_mutex); + /* It is not safe to use setgroups until a gid mapping in + * the user namespace has been established. + */ + allowed = ns->gid_map.nr_extents != 0; + /* Is setgroups allowed? */ + allowed = allowed && (ns->flags & USERNS_SETGROUPS_ALLOWED); + mutex_unlock(&userns_state_mutex); + + return allowed; +} + static void *userns_get(struct task_struct *task) { struct user_namespace *user_ns; |