* 30 May 2002: Cleanup, Robert M. Love <rml@tech9.net>
*/
+#include <linux/audit.h>
#include <linux/capability.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/syscalls.h>
#include <linux/pid_namespace.h>
#include <asm/uaccess.h>
-
-/*
- * This lock protects task->cap_* for all tasks including current.
- * Locking rule: acquire this prior to tasklist_lock.
- */
-static DEFINE_SPINLOCK(task_capability_lock);
+#include "cred-internals.h"
/*
* Leveraged for setting/resetting capabilities
EXPORT_SYMBOL(__cap_full_set);
EXPORT_SYMBOL(__cap_init_eff_set);
+int file_caps_enabled = 1;
+
+static int __init file_caps_disable(char *str)
+{
+ file_caps_enabled = 0;
+ return 1;
+}
+__setup("no_file_caps", file_caps_disable);
+
/*
* More recent versions of libcap are available from:
*
return 0;
}
-#ifndef CONFIG_SECURITY_FILE_CAPABILITIES
-
-/*
- * Without filesystem capability support, we nominally support one process
- * setting the capabilities of another
- */
-static inline int cap_get_target_pid(pid_t pid, kernel_cap_t *pEp,
- kernel_cap_t *pIp, kernel_cap_t *pPp)
-{
- struct task_struct *target;
- int ret;
-
- spin_lock(&task_capability_lock);
- read_lock(&tasklist_lock);
-
- if (pid && pid != task_pid_vnr(current)) {
- target = find_task_by_vpid(pid);
- if (!target) {
- ret = -ESRCH;
- goto out;
- }
- } else
- target = current;
-
- ret = security_capget(target, pEp, pIp, pPp);
-
-out:
- read_unlock(&tasklist_lock);
- spin_unlock(&task_capability_lock);
-
- return ret;
-}
-
-/*
- * cap_set_pg - set capabilities for all processes in a given process
- * group. We call this holding task_capability_lock and tasklist_lock.
- */
-static inline int cap_set_pg(int pgrp_nr, kernel_cap_t *effective,
- kernel_cap_t *inheritable,
- kernel_cap_t *permitted)
-{
- struct task_struct *g, *target;
- int ret = -EPERM;
- int found = 0;
- struct pid *pgrp;
-
- spin_lock(&task_capability_lock);
- read_lock(&tasklist_lock);
-
- pgrp = find_vpid(pgrp_nr);
- do_each_pid_task(pgrp, PIDTYPE_PGID, g) {
- target = g;
- while_each_thread(g, target) {
- if (!security_capset_check(target, effective,
- inheritable, permitted)) {
- security_capset_set(target, effective,
- inheritable, permitted);
- ret = 0;
- }
- found = 1;
- }
- } while_each_pid_task(pgrp, PIDTYPE_PGID, g);
-
- read_unlock(&tasklist_lock);
- spin_unlock(&task_capability_lock);
-
- if (!found)
- ret = 0;
- return ret;
-}
-
-/*
- * cap_set_all - set capabilities for all processes other than init
- * and self. We call this holding task_capability_lock and tasklist_lock.
- */
-static inline int cap_set_all(kernel_cap_t *effective,
- kernel_cap_t *inheritable,
- kernel_cap_t *permitted)
-{
- struct task_struct *g, *target;
- int ret = -EPERM;
- int found = 0;
-
- spin_lock(&task_capability_lock);
- read_lock(&tasklist_lock);
-
- do_each_thread(g, target) {
- if (target == current
- || is_container_init(target->group_leader))
- continue;
- found = 1;
- if (security_capset_check(target, effective, inheritable,
- permitted))
- continue;
- ret = 0;
- security_capset_set(target, effective, inheritable, permitted);
- } while_each_thread(g, target);
-
- read_unlock(&tasklist_lock);
- spin_unlock(&task_capability_lock);
-
- if (!found)
- ret = 0;
-
- return ret;
-}
-
-/*
- * Given the target pid does not refer to the current process we
- * need more elaborate support... (This support is not present when
- * filesystem capabilities are configured.)
- */
-static inline int do_sys_capset_other_tasks(pid_t pid, kernel_cap_t *effective,
- kernel_cap_t *inheritable,
- kernel_cap_t *permitted)
-{
- struct task_struct *target;
- int ret;
-
- if (!capable(CAP_SETPCAP))
- return -EPERM;
-
- if (pid == -1) /* all procs other than current and init */
- return cap_set_all(effective, inheritable, permitted);
-
- else if (pid < 0) /* all procs in process group */
- return cap_set_pg(-pid, effective, inheritable, permitted);
-
- /* target != current */
- spin_lock(&task_capability_lock);
- read_lock(&tasklist_lock);
-
- target = find_task_by_vpid(pid);
- if (!target)
- ret = -ESRCH;
- else {
- ret = security_capset_check(target, effective, inheritable,
- permitted);
-
- /* having verified that the proposed changes are legal,
- we now put them into effect. */
- if (!ret)
- security_capset_set(target, effective, inheritable,
- permitted);
- }
-
- read_unlock(&tasklist_lock);
- spin_unlock(&task_capability_lock);
-
- return ret;
-}
-
-#else /* ie., def CONFIG_SECURITY_FILE_CAPABILITIES */
-
/*
- * If we have configured with filesystem capability support, then the
- * only thing that can change the capabilities of the current process
- * is the current process. As such, we can't be in this code at the
- * same time as we are in the process of setting capabilities in this
- * process. The net result is that we can limit our use of locks to
- * when we are reading the caps of another process.
+ * The only thing that can change the capabilities of the current
+ * process is the current process. As such, we can't be in this code
+ * at the same time as we are in the process of setting capabilities
+ * in this process. The net result is that we can limit our use of
+ * locks to when we are reading the caps of another process.
*/
static inline int cap_get_target_pid(pid_t pid, kernel_cap_t *pEp,
kernel_cap_t *pIp, kernel_cap_t *pPp)
if (pid && (pid != task_pid_vnr(current))) {
struct task_struct *target;
- spin_lock(&task_capability_lock);
- read_lock(&tasklist_lock);
+ rcu_read_lock();
target = find_task_by_vpid(pid);
if (!target)
else
ret = security_capget(target, pEp, pIp, pPp);
- read_unlock(&tasklist_lock);
- spin_unlock(&task_capability_lock);
+ rcu_read_unlock();
} else
ret = security_capget(current, pEp, pIp, pPp);
return ret;
}
-/*
- * With filesystem capability support configured, the kernel does not
- * permit the changing of capabilities in one process by another
- * process. (CAP_SETPCAP has much less broad semantics when configured
- * this way.)
- */
-static inline int do_sys_capset_other_tasks(pid_t pid,
- kernel_cap_t *effective,
- kernel_cap_t *inheritable,
- kernel_cap_t *permitted)
-{
- return -EPERM;
-}
-
-#endif /* ie., ndef CONFIG_SECURITY_FILE_CAPABILITIES */
-
-/*
- * Atomically modify the effective capabilities returning the original
- * value. No permission check is performed here - it is assumed that the
- * caller is permitted to set the desired effective capabilities.
- */
-kernel_cap_t cap_set_effective(const kernel_cap_t pE_new)
-{
- kernel_cap_t pE_old;
-
- spin_lock(&task_capability_lock);
-
- pE_old = current->cap_effective;
- current->cap_effective = pE_new;
-
- spin_unlock(&task_capability_lock);
-
- return pE_old;
-}
-
-EXPORT_SYMBOL(cap_set_effective);
-
/**
* sys_capget - get the capabilities of a given process.
* @header: pointer to struct that contains capability version and
*
* Returns 0 on success and < 0 on error.
*/
-asmlinkage long sys_capget(cap_user_header_t header, cap_user_data_t dataptr)
+SYSCALL_DEFINE2(capget, cap_user_header_t, header, cap_user_data_t, dataptr)
{
int ret = 0;
pid_t pid;
kernel_cap_t pE, pI, pP;
ret = cap_validate_magic(header, &tocopy);
- if (ret != 0)
- return ret;
+ if ((dataptr == NULL) || (ret != 0))
+ return ((dataptr == NULL) && (ret == -EINVAL)) ? 0 : ret;
if (get_user(pid, &header->pid))
return -EFAULT;
return -EINVAL;
ret = cap_get_target_pid(pid, &pE, &pI, &pP);
-
if (!ret) {
struct __user_cap_data_struct kdata[_KERNEL_CAPABILITY_U32S];
unsigned i;
* @data: pointer to struct that contains the effective, permitted,
* and inheritable capabilities
*
- * Set capabilities for a given process, all processes, or all
- * processes in a given process group.
+ * Set capabilities for the current process only. The ability to any other
+ * process(es) has been deprecated and removed.
*
* The restrictions on setting capabilities are specified as:
*
- * [pid is for the 'target' task. 'current' is the calling task.]
- *
- * I: any raised capabilities must be a subset of the (old current) permitted
- * P: any raised capabilities must be a subset of the (old current) permitted
- * E: must be set to a subset of (new target) permitted
+ * I: any raised capabilities must be a subset of the old permitted
+ * P: any raised capabilities must be a subset of the old permitted
+ * E: must be set to a subset of new permitted
*
* Returns 0 on success and < 0 on error.
*/
-asmlinkage long sys_capset(cap_user_header_t header, const cap_user_data_t data)
+SYSCALL_DEFINE2(capset, cap_user_header_t, header, const cap_user_data_t, data)
{
struct __user_cap_data_struct kdata[_KERNEL_CAPABILITY_U32S];
- unsigned i, tocopy;
+ unsigned i, tocopy, copybytes;
kernel_cap_t inheritable, permitted, effective;
+ struct cred *new;
int ret;
pid_t pid;
if (get_user(pid, &header->pid))
return -EFAULT;
- if (copy_from_user(&kdata, data, tocopy
- * sizeof(struct __user_cap_data_struct))) {
+ /* may only affect current now */
+ if (pid != 0 && pid != task_pid_vnr(current))
+ return -EPERM;
+
+ copybytes = tocopy * sizeof(struct __user_cap_data_struct);
+ if (copybytes > sizeof(kdata))
+ return -EFAULT;
+
+ if (copy_from_user(&kdata, data, copybytes))
return -EFAULT;
- }
for (i = 0; i < tocopy; i++) {
effective.cap[i] = kdata[i].effective;
i++;
}
- if (pid && (pid != task_pid_vnr(current)))
- ret = do_sys_capset_other_tasks(pid, &effective, &inheritable,
- &permitted);
- else {
- /*
- * This lock is required even when filesystem
- * capability support is configured - it protects the
- * sys_capget() call from returning incorrect data in
- * the case that the targeted process is not the
- * current one.
- */
- spin_lock(&task_capability_lock);
+ new = prepare_creds();
+ if (!new)
+ return -ENOMEM;
- ret = security_capset_check(current, &effective, &inheritable,
- &permitted);
- /*
- * Having verified that the proposed changes are
- * legal, we now put them into effect.
- */
- if (!ret)
- security_capset_set(current, &effective, &inheritable,
- &permitted);
- spin_unlock(&task_capability_lock);
- }
+ ret = security_capset(new, current_cred(),
+ &effective, &inheritable, &permitted);
+ if (ret < 0)
+ goto error;
+ audit_log_capset(pid, new, current_cred());
+ return commit_creds(new);
+
+error:
+ abort_creds(new);
return ret;
}
-int __capable(struct task_struct *t, int cap)
+/**
+ * capable - Determine if the current task has a superior capability in effect
+ * @cap: The capability to be tested for
+ *
+ * Return true if the current task has the given superior capability currently
+ * available for use, false if not.
+ *
+ * This sets PF_SUPERPRIV on the task if the capability is available on the
+ * assumption that it's about to be used.
+ */
+int capable(int cap)
{
- if (security_capable(t, cap) == 0) {
- t->flags |= PF_SUPERPRIV;
+ if (unlikely(!cap_valid(cap))) {
+ printk(KERN_CRIT "capable() called with invalid cap=%u\n", cap);
+ BUG();
+ }
+
+ if (security_capable(cap) == 0) {
+ current->flags |= PF_SUPERPRIV;
return 1;
}
return 0;
}
-
-int capable(int cap)
-{
- return __capable(current, cap);
-}
EXPORT_SYMBOL(capable);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff