#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
-#include <linux/security.h>
+#include <linux/lsm_hooks.h>
#include <linux/file.h>
#include <linux/mm.h>
#include <linux/mman.h>
}
}
-int cap_netlink_send(struct sock *sk, struct sk_buff *skb)
-{
- return 0;
-}
-
/**
* cap_capable - Determine whether a task has a particular effective capability
* @cred: The credentials to use
{
int ret = 0;
const struct cred *cred, *child_cred;
+ const kernel_cap_t *caller_caps;
rcu_read_lock();
cred = current_cred();
child_cred = __task_cred(child);
+ if (mode & PTRACE_MODE_FSCREDS)
+ caller_caps = &cred->cap_effective;
+ else
+ caller_caps = &cred->cap_permitted;
if (cred->user_ns == child_cred->user_ns &&
- cap_issubset(child_cred->cap_permitted, cred->cap_permitted))
+ cap_issubset(child_cred->cap_permitted, *caller_caps))
goto out;
if (ns_capable(child_cred->user_ns, CAP_SYS_PTRACE))
goto out;
new->cap_effective = *effective;
new->cap_inheritable = *inheritable;
new->cap_permitted = *permitted;
+
+ /*
+ * Mask off ambient bits that are no longer both permitted and
+ * inheritable.
+ */
+ new->cap_ambient = cap_intersect(new->cap_ambient,
+ cap_intersect(*permitted,
+ *inheritable));
+ if (WARN_ON(!cap_ambient_invariant_ok(new)))
+ return -EINVAL;
return 0;
}
/*
* pP' = (X & fP) | (pI & fI)
+ * The addition of pA' is handled later.
*/
new->cap_permitted.cap[i] =
(new->cap_bset.cap[i] & permitted) |
{
const struct cred *old = current_cred();
struct cred *new = bprm->cred;
- bool effective, has_cap = false;
+ bool effective, has_cap = false, is_setid;
int ret;
kuid_t root_uid;
+ if (WARN_ON(!cap_ambient_invariant_ok(old)))
+ return -EPERM;
+
effective = false;
ret = get_file_caps(bprm, &effective, &has_cap);
if (ret < 0)
*
* In addition, if NO_NEW_PRIVS, then ensure we get no new privs.
*/
- if ((!uid_eq(new->euid, old->uid) ||
- !gid_eq(new->egid, old->gid) ||
+ is_setid = !uid_eq(new->euid, old->uid) || !gid_eq(new->egid, old->gid);
+
+ if ((is_setid ||
!cap_issubset(new->cap_permitted, old->cap_permitted)) &&
bprm->unsafe & ~LSM_UNSAFE_PTRACE_CAP) {
/* downgrade; they get no more than they had, and maybe less */
new->suid = new->fsuid = new->euid;
new->sgid = new->fsgid = new->egid;
+ /* File caps or setid cancels ambient. */
+ if (has_cap || is_setid)
+ cap_clear(new->cap_ambient);
+
+ /*
+ * Now that we've computed pA', update pP' to give:
+ * pP' = (X & fP) | (pI & fI) | pA'
+ */
+ new->cap_permitted = cap_combine(new->cap_permitted, new->cap_ambient);
+
+ /*
+ * Set pE' = (fE ? pP' : pA'). Because pA' is zero if fE is set,
+ * this is the same as pE' = (fE ? pP' : 0) | pA'.
+ */
if (effective)
new->cap_effective = new->cap_permitted;
else
- cap_clear(new->cap_effective);
+ new->cap_effective = new->cap_ambient;
+
+ if (WARN_ON(!cap_ambient_invariant_ok(new)))
+ return -EPERM;
+
bprm->cap_effective = effective;
/*
* Number 1 above might fail if you don't have a full bset, but I think
* that is interesting information to audit.
*/
- if (!cap_isclear(new->cap_effective)) {
+ if (!cap_issubset(new->cap_effective, new->cap_ambient)) {
if (!cap_issubset(CAP_FULL_SET, new->cap_effective) ||
!uid_eq(new->euid, root_uid) || !uid_eq(new->uid, root_uid) ||
issecure(SECURE_NOROOT)) {
}
new->securebits &= ~issecure_mask(SECURE_KEEP_CAPS);
+
+ if (WARN_ON(!cap_ambient_invariant_ok(new)))
+ return -EPERM;
+
return 0;
}
if (!uid_eq(cred->uid, root_uid)) {
if (bprm->cap_effective)
return 1;
- if (!cap_isclear(cred->cap_permitted))
+ if (!cap_issubset(cred->cap_permitted, cred->cap_ambient))
return 1;
}
uid_eq(old->suid, root_uid)) &&
(!uid_eq(new->uid, root_uid) &&
!uid_eq(new->euid, root_uid) &&
- !uid_eq(new->suid, root_uid)) &&
- !issecure(SECURE_KEEP_CAPS)) {
- cap_clear(new->cap_permitted);
- cap_clear(new->cap_effective);
+ !uid_eq(new->suid, root_uid))) {
+ if (!issecure(SECURE_KEEP_CAPS)) {
+ cap_clear(new->cap_permitted);
+ cap_clear(new->cap_effective);
+ }
+
+ /*
+ * Pre-ambient programs expect setresuid to nonroot followed
+ * by exec to drop capabilities. We should make sure that
+ * this remains the case.
+ */
+ cap_clear(new->cap_ambient);
}
if (uid_eq(old->euid, root_uid) && !uid_eq(new->euid, root_uid))
cap_clear(new->cap_effective);
new->securebits &= ~issecure_mask(SECURE_KEEP_CAPS);
return commit_creds(new);
+ case PR_CAP_AMBIENT:
+ if (arg2 == PR_CAP_AMBIENT_CLEAR_ALL) {
+ if (arg3 | arg4 | arg5)
+ return -EINVAL;
+
+ new = prepare_creds();
+ if (!new)
+ return -ENOMEM;
+ cap_clear(new->cap_ambient);
+ return commit_creds(new);
+ }
+
+ if (((!cap_valid(arg3)) | arg4 | arg5))
+ return -EINVAL;
+
+ if (arg2 == PR_CAP_AMBIENT_IS_SET) {
+ return !!cap_raised(current_cred()->cap_ambient, arg3);
+ } else if (arg2 != PR_CAP_AMBIENT_RAISE &&
+ arg2 != PR_CAP_AMBIENT_LOWER) {
+ return -EINVAL;
+ } else {
+ if (arg2 == PR_CAP_AMBIENT_RAISE &&
+ (!cap_raised(current_cred()->cap_permitted, arg3) ||
+ !cap_raised(current_cred()->cap_inheritable,
+ arg3) ||
+ issecure(SECURE_NO_CAP_AMBIENT_RAISE)))
+ return -EPERM;
+
+ new = prepare_creds();
+ if (!new)
+ return -ENOMEM;
+ if (arg2 == PR_CAP_AMBIENT_RAISE)
+ cap_raise(new->cap_ambient, arg3);
+ else
+ cap_lower(new->cap_ambient, arg3);
+ return commit_creds(new);
+ }
+
default:
/* No functionality available - continue with default */
return -ENOSYS;
* @pages: The size of the mapping
*
* Determine whether the allocation of a new virtual mapping by the current
- * task is permitted, returning 0 if permission is granted, -ve if not.
+ * task is permitted, returning 1 if permission is granted, 0 if not.
*/
int cap_vm_enough_memory(struct mm_struct *mm, long pages)
{
if (cap_capable(current_cred(), &init_user_ns, CAP_SYS_ADMIN,
SECURITY_CAP_NOAUDIT) == 0)
cap_sys_admin = 1;
- return __vm_enough_memory(mm, pages, cap_sys_admin);
+ return cap_sys_admin;
}
/*
{
return 0;
}
+
+#ifdef CONFIG_SECURITY
+
+struct security_hook_list capability_hooks[] = {
+ LSM_HOOK_INIT(capable, cap_capable),
+ LSM_HOOK_INIT(settime, cap_settime),
+ LSM_HOOK_INIT(ptrace_access_check, cap_ptrace_access_check),
+ LSM_HOOK_INIT(ptrace_traceme, cap_ptrace_traceme),
+ LSM_HOOK_INIT(capget, cap_capget),
+ LSM_HOOK_INIT(capset, cap_capset),
+ LSM_HOOK_INIT(bprm_set_creds, cap_bprm_set_creds),
+ LSM_HOOK_INIT(bprm_secureexec, cap_bprm_secureexec),
+ LSM_HOOK_INIT(inode_need_killpriv, cap_inode_need_killpriv),
+ LSM_HOOK_INIT(inode_killpriv, cap_inode_killpriv),
+ LSM_HOOK_INIT(mmap_addr, cap_mmap_addr),
+ LSM_HOOK_INIT(mmap_file, cap_mmap_file),
+ LSM_HOOK_INIT(task_fix_setuid, cap_task_fix_setuid),
+ LSM_HOOK_INIT(task_prctl, cap_task_prctl),
+ LSM_HOOK_INIT(task_setscheduler, cap_task_setscheduler),
+ LSM_HOOK_INIT(task_setioprio, cap_task_setioprio),
+ LSM_HOOK_INIT(task_setnice, cap_task_setnice),
+ LSM_HOOK_INIT(vm_enough_memory, cap_vm_enough_memory),
+};
+
+void __init capability_add_hooks(void)
+{
+ security_add_hooks(capability_hooks, ARRAY_SIZE(capability_hooks));
+}
+
+#endif /* CONFIG_SECURITY */
Code Review / kvmfornfv.git / blobdiff