[RTNL]: Validate hardware and broadcast address attribute for RTM_NEWLINK
[sfrench/cifs-2.6.git] / kernel / capability.c
index cbc5fd60c0f318dce6c1cdcd33b4cf5b5d37f6a1..39e8193b41ea658f1d67fca1d91edb38e698edea 100644 (file)
@@ -12,6 +12,7 @@
 #include <linux/module.h>
 #include <linux/security.h>
 #include <linux/syscalls.h>
+#include <linux/pid_namespace.h>
 #include <asm/uaccess.h>
 
 /*
  */
 static DEFINE_SPINLOCK(task_capability_lock);
 
+/*
+ * Leveraged for setting/resetting capabilities
+ */
+
+const kernel_cap_t __cap_empty_set = CAP_EMPTY_SET;
+const kernel_cap_t __cap_full_set = CAP_FULL_SET;
+const kernel_cap_t __cap_init_eff_set = CAP_INIT_EFF_SET;
+
+EXPORT_SYMBOL(__cap_empty_set);
+EXPORT_SYMBOL(__cap_full_set);
+EXPORT_SYMBOL(__cap_init_eff_set);
+
+/*
+ * More recent versions of libcap are available from:
+ *
+ *   http://www.kernel.org/pub/linux/libs/security/linux-privs/
+ */
+
+static void warn_legacy_capability_use(void)
+{
+       static int warned;
+       if (!warned) {
+               char name[sizeof(current->comm)];
+
+               printk(KERN_INFO "warning: `%s' uses 32-bit capabilities"
+                      " (legacy support in use)\n",
+                      get_task_comm(name, current));
+               warned = 1;
+       }
+}
+
 /*
  * For sys_getproccap() and sys_setproccap(), any of the three
  * capability set pointers may be NULL -- indicating that that set is
@@ -41,12 +73,21 @@ asmlinkage long sys_capget(cap_user_header_t header, cap_user_data_t dataptr)
        pid_t pid;
        __u32 version;
        struct task_struct *target;
-       struct __user_cap_data_struct data;
+       unsigned tocopy;
+       kernel_cap_t pE, pI, pP;
 
        if (get_user(version, &header->version))
                return -EFAULT;
 
-       if (version != _LINUX_CAPABILITY_VERSION) {
+       switch (version) {
+       case _LINUX_CAPABILITY_VERSION_1:
+               warn_legacy_capability_use();
+               tocopy = _LINUX_CAPABILITY_U32S_1;
+               break;
+       case _LINUX_CAPABILITY_VERSION_2:
+               tocopy = _LINUX_CAPABILITY_U32S_2;
+               break;
+       default:
                if (put_user(_LINUX_CAPABILITY_VERSION, &header->version))
                        return -EFAULT;
                return -EINVAL;
@@ -61,8 +102,8 @@ asmlinkage long sys_capget(cap_user_header_t header, cap_user_data_t dataptr)
        spin_lock(&task_capability_lock);
        read_lock(&tasklist_lock);
 
-       if (pid && pid != current->pid) {
-               target = find_task_by_pid(pid);
+       if (pid && pid != task_pid_vnr(current)) {
+               target = find_task_by_vpid(pid);
                if (!target) {
                        ret = -ESRCH;
                        goto out;
@@ -70,14 +111,47 @@ asmlinkage long sys_capget(cap_user_header_t header, cap_user_data_t dataptr)
        } else
                target = current;
 
-       ret = security_capget(target, &data.effective, &data.inheritable, &data.permitted);
+       ret = security_capget(target, &pE, &pI, &pP);
 
 out:
        read_unlock(&tasklist_lock);
        spin_unlock(&task_capability_lock);
 
-       if (!ret && copy_to_user(dataptr, &data, sizeof data))
-               return -EFAULT;
+       if (!ret) {
+               struct __user_cap_data_struct kdata[_LINUX_CAPABILITY_U32S];
+               unsigned i;
+
+               for (i = 0; i < tocopy; i++) {
+                       kdata[i].effective = pE.cap[i];
+                       kdata[i].permitted = pP.cap[i];
+                       kdata[i].inheritable = pI.cap[i];
+               }
+
+               /*
+                * Note, in the case, tocopy < _LINUX_CAPABILITY_U32S,
+                * we silently drop the upper capabilities here. This
+                * has the effect of making older libcap
+                * implementations implicitly drop upper capability
+                * bits when they perform a: capget/modify/capset
+                * sequence.
+                *
+                * This behavior is considered fail-safe
+                * behavior. Upgrading the application to a newer
+                * version of libcap will enable access to the newer
+                * capabilities.
+                *
+                * An alternative would be to return an error here
+                * (-ERANGE), but that causes legacy applications to
+                * unexpectidly fail; the capget/modify/capset aborts
+                * before modification is attempted and the application
+                * fails.
+                */
+
+               if (copy_to_user(dataptr, kdata, tocopy
+                                * sizeof(struct __user_cap_data_struct))) {
+                       return -EFAULT;
+               }
+       }
 
        return ret;
 }
@@ -95,7 +169,7 @@ static inline int cap_set_pg(int pgrp_nr, kernel_cap_t *effective,
        int found = 0;
        struct pid *pgrp;
 
-       pgrp = find_pid(pgrp_nr);
+       pgrp = find_vpid(pgrp_nr);
        do_each_pid_task(pgrp, PIDTYPE_PGID, g) {
                target = g;
                while_each_thread(g, target) {
@@ -129,7 +203,7 @@ static inline int cap_set_all(kernel_cap_t *effective,
      int found = 0;
 
      do_each_thread(g, target) {
-             if (target == current || is_init(target))
+             if (target == current || is_container_init(target->group_leader))
                      continue;
              found = 1;
             if (security_capset_check(target, effective, inheritable,
@@ -166,6 +240,8 @@ static inline int cap_set_all(kernel_cap_t *effective,
  */
 asmlinkage long sys_capset(cap_user_header_t header, const cap_user_data_t data)
 {
+       struct __user_cap_data_struct kdata[_LINUX_CAPABILITY_U32S];
+       unsigned i, tocopy;
        kernel_cap_t inheritable, permitted, effective;
        __u32 version;
        struct task_struct *target;
@@ -175,7 +251,15 @@ asmlinkage long sys_capset(cap_user_header_t header, const cap_user_data_t data)
        if (get_user(version, &header->version))
                return -EFAULT;
 
-       if (version != _LINUX_CAPABILITY_VERSION) {
+       switch (version) {
+       case _LINUX_CAPABILITY_VERSION_1:
+               warn_legacy_capability_use();
+               tocopy = _LINUX_CAPABILITY_U32S_1;
+               break;
+       case _LINUX_CAPABILITY_VERSION_2:
+               tocopy = _LINUX_CAPABILITY_U32S_2;
+               break;
+       default:
                if (put_user(_LINUX_CAPABILITY_VERSION, &header->version))
                        return -EFAULT;
                return -EINVAL;
@@ -184,19 +268,31 @@ asmlinkage long sys_capset(cap_user_header_t header, const cap_user_data_t data)
        if (get_user(pid, &header->pid))
                return -EFAULT;
 
-       if (pid && pid != current->pid && !capable(CAP_SETPCAP))
+       if (pid && pid != task_pid_vnr(current) && !capable(CAP_SETPCAP))
                return -EPERM;
 
-       if (copy_from_user(&effective, &data->effective, sizeof(effective)) ||
-           copy_from_user(&inheritable, &data->inheritable, sizeof(inheritable)) ||
-           copy_from_user(&permitted, &data->permitted, sizeof(permitted)))
+       if (copy_from_user(&kdata, data, tocopy
+                          * sizeof(struct __user_cap_data_struct))) {
                return -EFAULT;
+       }
+
+       for (i = 0; i < tocopy; i++) {
+               effective.cap[i] = kdata[i].effective;
+               permitted.cap[i] = kdata[i].permitted;
+               inheritable.cap[i] = kdata[i].inheritable;
+       }
+       while (i < _LINUX_CAPABILITY_U32S) {
+               effective.cap[i] = 0;
+               permitted.cap[i] = 0;
+               inheritable.cap[i] = 0;
+               i++;
+       }
 
        spin_lock(&task_capability_lock);
        read_lock(&tasklist_lock);
 
-       if (pid > 0 && pid != current->pid) {
-               target = find_task_by_pid(pid);
+       if (pid > 0 && pid != task_pid_vnr(current)) {
+               target = find_task_by_vpid(pid);
                if (!target) {
                        ret = -ESRCH;
                        goto out;