2 * linux/kernel/capability.c
4 * Copyright (C) 1997 Andrew Main <zefram@fysh.org>
6 * Integrated into 2.1.97+, Andrew G. Morgan <morgan@transmeta.com>
7 * 30 May 2002: Cleanup, Robert M. Love <rml@tech9.net>
11 #include <linux/module.h>
12 #include <linux/security.h>
13 #include <linux/syscalls.h>
14 #include <linux/vs_cvirt.h>
15 #include <asm/uaccess.h>
17 unsigned securebits = SECUREBITS_DEFAULT; /* systemwide security settings */
18 kernel_cap_t cap_bset = CAP_INIT_EFF_SET;
20 EXPORT_SYMBOL(securebits);
21 EXPORT_SYMBOL(cap_bset);
24 * This lock protects task->cap_* for all tasks including current.
25 * Locking rule: acquire this prior to tasklist_lock.
27 static DEFINE_SPINLOCK(task_capability_lock);
30 * For sys_getproccap() and sys_setproccap(), any of the three
31 * capability set pointers may be NULL -- indicating that that set is
32 * uninteresting and/or not to be changed.
36 * sys_capget - get the capabilities of a given process.
38 asmlinkage long sys_capget(cap_user_header_t header, cap_user_data_t dataptr)
44 struct __user_cap_data_struct data;
46 if (get_user(version, &header->version))
49 if (version != _LINUX_CAPABILITY_VERSION) {
50 if (put_user(_LINUX_CAPABILITY_VERSION, &header->version))
55 if (get_user(pid, &header->pid))
61 spin_lock(&task_capability_lock);
62 read_lock(&tasklist_lock);
64 if (pid && pid != current->pid) {
65 target = find_task_by_pid(pid);
73 ret = security_capget(target, &data.effective, &data.inheritable, &data.permitted);
76 read_unlock(&tasklist_lock);
77 spin_unlock(&task_capability_lock);
79 if (!ret && copy_to_user(dataptr, &data, sizeof data))
86 * cap_set_pg - set capabilities for all processes in a given process
87 * group. We call this holding task_capability_lock and tasklist_lock.
89 static inline int cap_set_pg(int pgrp, kernel_cap_t *effective,
90 kernel_cap_t *inheritable,
91 kernel_cap_t *permitted)
97 do_each_task_pid(pgrp, PIDTYPE_PGID, g) {
99 while_each_thread(g, target) {
100 if (!security_capset_check(target, effective,
103 security_capset_set(target, effective,
110 } while_each_task_pid(pgrp, PIDTYPE_PGID, g);
118 * cap_set_all - set capabilities for all processes other than init
119 * and self. We call this holding task_capability_lock and tasklist_lock.
121 static inline int cap_set_all(kernel_cap_t *effective,
122 kernel_cap_t *inheritable,
123 kernel_cap_t *permitted)
129 do_each_thread(g, target) {
130 if (target == current || target->pid == 1)
133 if (security_capset_check(target, effective, inheritable,
137 security_capset_set(target, effective, inheritable, permitted);
138 } while_each_thread(g, target);
146 * sys_capset - set capabilities for a given process, all processes, or all
147 * processes in a given process group.
149 * The restrictions on setting capabilities are specified as:
151 * [pid is for the 'target' task. 'current' is the calling task.]
153 * I: any raised capabilities must be a subset of the (old current) permitted
154 * P: any raised capabilities must be a subset of the (old current) permitted
155 * E: must be set to a subset of (new target) permitted
157 asmlinkage long sys_capset(cap_user_header_t header, const cap_user_data_t data)
159 kernel_cap_t inheritable, permitted, effective;
165 if (get_user(version, &header->version))
168 if (version != _LINUX_CAPABILITY_VERSION) {
169 if (put_user(_LINUX_CAPABILITY_VERSION, &header->version))
174 if (get_user(pid, &header->pid))
177 if (pid && pid != current->pid && !capable(CAP_SETPCAP))
180 if (copy_from_user(&effective, &data->effective, sizeof(effective)) ||
181 copy_from_user(&inheritable, &data->inheritable, sizeof(inheritable)) ||
182 copy_from_user(&permitted, &data->permitted, sizeof(permitted)))
185 spin_lock(&task_capability_lock);
186 read_lock(&tasklist_lock);
188 if (pid > 0 && pid != current->pid) {
189 target = find_task_by_pid(pid);
199 /* having verified that the proposed changes are legal,
200 we now put them into effect. */
202 if (pid == -1) /* all procs other than current and init */
203 ret = cap_set_all(&effective, &inheritable, &permitted);
205 else /* all procs in process group */
206 ret = cap_set_pg(-pid, &effective, &inheritable,
209 ret = security_capset_check(target, &effective, &inheritable,
212 security_capset_set(target, &effective, &inheritable,
217 read_unlock(&tasklist_lock);
218 spin_unlock(&task_capability_lock);