/*
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/*
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* linux/kernel/capability.c
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* linux/kernel/capability.c
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*
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*
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* Copyright (C) 1997 Andrew Main <zefram@fysh.org>
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* Copyright (C) 1997 Andrew Main <zefram@fysh.org>
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* Integrated into 2.1.97+, Andrew G. Morgan <morgan@transmeta.com>
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* Integrated into 2.1.97+, Andrew G. Morgan <morgan@transmeta.com>
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*/
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*/
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#include <linux/mm.h>
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#include <linux/mm.h>
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#include <asm/uaccess.h>
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#include <asm/uaccess.h>
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kernel_cap_t cap_bset = CAP_INIT_EFF_SET;
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kernel_cap_t cap_bset = CAP_INIT_EFF_SET;
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/* Note: never hold tasklist_lock while spinning for this one */
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/* Note: never hold tasklist_lock while spinning for this one */
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spinlock_t task_capability_lock = SPIN_LOCK_UNLOCKED;
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spinlock_t task_capability_lock = SPIN_LOCK_UNLOCKED;
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/*
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/*
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* For sys_getproccap() and sys_setproccap(), any of the three
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* For sys_getproccap() and sys_setproccap(), any of the three
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* capability set pointers may be NULL -- indicating that that set is
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* capability set pointers may be NULL -- indicating that that set is
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* uninteresting and/or not to be changed.
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* uninteresting and/or not to be changed.
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*/
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*/
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asmlinkage long sys_capget(cap_user_header_t header, cap_user_data_t dataptr)
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asmlinkage long sys_capget(cap_user_header_t header, cap_user_data_t dataptr)
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{
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{
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int error, pid;
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int error, pid;
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__u32 version;
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__u32 version;
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struct task_struct *target;
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struct task_struct *target;
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struct __user_cap_data_struct data;
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struct __user_cap_data_struct data;
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if (get_user(version, &header->version))
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if (get_user(version, &header->version))
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return -EFAULT;
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return -EFAULT;
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error = -EINVAL;
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error = -EINVAL;
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if (version != _LINUX_CAPABILITY_VERSION) {
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if (version != _LINUX_CAPABILITY_VERSION) {
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version = _LINUX_CAPABILITY_VERSION;
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version = _LINUX_CAPABILITY_VERSION;
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if (put_user(version, &header->version))
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if (put_user(version, &header->version))
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error = -EFAULT;
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error = -EFAULT;
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return error;
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return error;
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}
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}
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if (get_user(pid, &header->pid))
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if (get_user(pid, &header->pid))
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return -EFAULT;
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return -EFAULT;
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if (pid < 0)
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if (pid < 0)
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return -EINVAL;
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return -EINVAL;
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error = 0;
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error = 0;
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spin_lock(&task_capability_lock);
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spin_lock(&task_capability_lock);
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if (pid && pid != current->pid) {
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if (pid && pid != current->pid) {
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read_lock(&tasklist_lock);
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read_lock(&tasklist_lock);
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target = find_task_by_pid(pid); /* identify target of query */
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target = find_task_by_pid(pid); /* identify target of query */
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if (!target)
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if (!target)
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error = -ESRCH;
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error = -ESRCH;
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} else {
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} else {
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target = current;
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target = current;
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}
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}
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if (!error) {
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if (!error) {
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data.permitted = cap_t(target->cap_permitted);
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data.permitted = cap_t(target->cap_permitted);
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data.inheritable = cap_t(target->cap_inheritable);
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data.inheritable = cap_t(target->cap_inheritable);
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data.effective = cap_t(target->cap_effective);
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data.effective = cap_t(target->cap_effective);
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}
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}
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if (target != current)
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if (target != current)
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read_unlock(&tasklist_lock);
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read_unlock(&tasklist_lock);
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spin_unlock(&task_capability_lock);
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spin_unlock(&task_capability_lock);
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if (!error) {
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if (!error) {
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if (copy_to_user(dataptr, &data, sizeof data))
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if (copy_to_user(dataptr, &data, sizeof data))
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return -EFAULT;
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return -EFAULT;
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}
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}
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return error;
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return error;
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}
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}
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/* set capabilities for all processes in a given process group */
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/* set capabilities for all processes in a given process group */
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static void cap_set_pg(int pgrp,
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static void cap_set_pg(int pgrp,
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kernel_cap_t *effective,
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kernel_cap_t *effective,
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kernel_cap_t *inheritable,
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kernel_cap_t *inheritable,
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kernel_cap_t *permitted)
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kernel_cap_t *permitted)
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{
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{
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struct task_struct *target;
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struct task_struct *target;
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/* FIXME: do we need to have a write lock here..? */
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/* FIXME: do we need to have a write lock here..? */
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read_lock(&tasklist_lock);
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read_lock(&tasklist_lock);
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for_each_task(target) {
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for_each_task(target) {
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if (target->pgrp != pgrp)
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if (target->pgrp != pgrp)
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continue;
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continue;
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target->cap_effective = *effective;
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target->cap_effective = *effective;
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target->cap_inheritable = *inheritable;
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target->cap_inheritable = *inheritable;
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target->cap_permitted = *permitted;
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target->cap_permitted = *permitted;
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}
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}
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read_unlock(&tasklist_lock);
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read_unlock(&tasklist_lock);
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}
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}
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/* set capabilities for all processes other than 1 and self */
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/* set capabilities for all processes other than 1 and self */
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static void cap_set_all(kernel_cap_t *effective,
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static void cap_set_all(kernel_cap_t *effective,
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kernel_cap_t *inheritable,
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kernel_cap_t *inheritable,
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kernel_cap_t *permitted)
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kernel_cap_t *permitted)
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{
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{
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struct task_struct *target;
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struct task_struct *target;
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/* FIXME: do we need to have a write lock here..? */
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/* FIXME: do we need to have a write lock here..? */
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read_lock(&tasklist_lock);
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read_lock(&tasklist_lock);
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/* ALL means everyone other than self or 'init' */
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/* ALL means everyone other than self or 'init' */
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for_each_task(target) {
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for_each_task(target) {
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if (target == current || target->pid == 1)
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if (target == current || target->pid == 1)
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continue;
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continue;
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target->cap_effective = *effective;
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target->cap_effective = *effective;
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target->cap_inheritable = *inheritable;
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target->cap_inheritable = *inheritable;
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target->cap_permitted = *permitted;
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target->cap_permitted = *permitted;
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}
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}
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read_unlock(&tasklist_lock);
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read_unlock(&tasklist_lock);
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}
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}
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/*
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/*
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* The restrictions on setting capabilities are specified as:
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* The restrictions on setting capabilities are specified as:
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*
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*
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* [pid is for the 'target' task. 'current' is the calling task.]
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* [pid is for the 'target' task. 'current' is the calling task.]
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*
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*
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* I: any raised capabilities must be a subset of the (old current) Permitted
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* I: any raised capabilities must be a subset of the (old current) Permitted
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* P: any raised capabilities must be a subset of the (old current) permitted
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* P: any raised capabilities must be a subset of the (old current) permitted
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* E: must be set to a subset of (new target) Permitted
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* E: must be set to a subset of (new target) Permitted
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*/
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*/
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asmlinkage long sys_capset(cap_user_header_t header, const cap_user_data_t data)
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asmlinkage long sys_capset(cap_user_header_t header, const cap_user_data_t data)
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{
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{
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kernel_cap_t inheritable, permitted, effective;
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kernel_cap_t inheritable, permitted, effective;
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__u32 version;
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__u32 version;
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struct task_struct *target;
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struct task_struct *target;
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int error, pid;
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int error, pid;
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if (get_user(version, &header->version))
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if (get_user(version, &header->version))
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return -EFAULT;
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return -EFAULT;
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if (version != _LINUX_CAPABILITY_VERSION) {
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if (version != _LINUX_CAPABILITY_VERSION) {
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version = _LINUX_CAPABILITY_VERSION;
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version = _LINUX_CAPABILITY_VERSION;
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if (put_user(version, &header->version))
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if (put_user(version, &header->version))
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return -EFAULT;
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return -EFAULT;
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return -EINVAL;
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return -EINVAL;
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}
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}
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if (get_user(pid, &header->pid))
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if (get_user(pid, &header->pid))
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return -EFAULT;
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return -EFAULT;
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if (pid && !capable(CAP_SETPCAP))
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if (pid && !capable(CAP_SETPCAP))
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return -EPERM;
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return -EPERM;
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if (copy_from_user(&effective, &data->effective, sizeof(effective)) ||
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if (copy_from_user(&effective, &data->effective, sizeof(effective)) ||
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copy_from_user(&inheritable, &data->inheritable, sizeof(inheritable)) ||
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copy_from_user(&inheritable, &data->inheritable, sizeof(inheritable)) ||
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copy_from_user(&permitted, &data->permitted, sizeof(permitted)))
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copy_from_user(&permitted, &data->permitted, sizeof(permitted)))
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return -EFAULT;
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return -EFAULT;
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error = -EPERM;
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error = -EPERM;
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spin_lock(&task_capability_lock);
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spin_lock(&task_capability_lock);
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if (pid > 0 && pid != current->pid) {
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if (pid > 0 && pid != current->pid) {
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read_lock(&tasklist_lock);
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read_lock(&tasklist_lock);
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target = find_task_by_pid(pid); /* identify target of query */
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target = find_task_by_pid(pid); /* identify target of query */
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if (!target) {
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if (!target) {
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error = -ESRCH;
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error = -ESRCH;
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goto out;
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goto out;
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}
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}
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} else {
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} else {
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target = current;
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target = current;
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}
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}
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/* verify restrictions on target's new Inheritable set */
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/* verify restrictions on target's new Inheritable set */
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if (!cap_issubset(inheritable,
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if (!cap_issubset(inheritable,
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cap_combine(target->cap_inheritable,
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cap_combine(target->cap_inheritable,
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current->cap_permitted))) {
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current->cap_permitted))) {
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goto out;
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goto out;
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}
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}
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/* verify restrictions on target's new Permitted set */
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/* verify restrictions on target's new Permitted set */
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if (!cap_issubset(permitted,
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if (!cap_issubset(permitted,
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cap_combine(target->cap_permitted,
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cap_combine(target->cap_permitted,
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current->cap_permitted))) {
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current->cap_permitted))) {
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goto out;
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goto out;
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}
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}
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/* verify the _new_Effective_ is a subset of the _new_Permitted_ */
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/* verify the _new_Effective_ is a subset of the _new_Permitted_ */
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if (!cap_issubset(effective, permitted)) {
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if (!cap_issubset(effective, permitted)) {
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goto out;
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goto out;
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}
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}
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/* having verified that the proposed changes are legal,
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/* having verified that the proposed changes are legal,
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we now put them into effect. */
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we now put them into effect. */
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error = 0;
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error = 0;
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if (pid < 0) {
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if (pid < 0) {
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if (pid == -1) /* all procs other than current and init */
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if (pid == -1) /* all procs other than current and init */
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cap_set_all(&effective, &inheritable, &permitted);
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cap_set_all(&effective, &inheritable, &permitted);
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else /* all procs in process group */
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else /* all procs in process group */
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cap_set_pg(-pid, &effective, &inheritable, &permitted);
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cap_set_pg(-pid, &effective, &inheritable, &permitted);
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goto spin_out;
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goto spin_out;
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} else {
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} else {
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/* FIXME: do we need to have a write lock here..? */
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/* FIXME: do we need to have a write lock here..? */
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target->cap_effective = effective;
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target->cap_effective = effective;
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target->cap_inheritable = inheritable;
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target->cap_inheritable = inheritable;
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target->cap_permitted = permitted;
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target->cap_permitted = permitted;
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}
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}
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out:
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out:
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if (target != current) {
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if (target != current) {
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read_unlock(&tasklist_lock);
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read_unlock(&tasklist_lock);
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}
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}
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spin_out:
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spin_out:
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spin_unlock(&task_capability_lock);
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spin_unlock(&task_capability_lock);
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return error;
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return error;
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}
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}
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