/**
* cap_capable - Determine whether a task has a particular effective capability
* @cred: The credentials to use
- * @ns: The user namespace in which we need the capability
+ * @targ_ns: The user namespace in which we need the capability
* @cap: The capability to check for
* @opts: Bitmask of options defined in include/linux/security.h
*
* affects the security markings on that inode, and if it is, should
* inode_killpriv() be invoked or the change rejected.
*
- * Returns 1 if security.capability has a value, meaning inode_killpriv()
+ * Return: 1 if security.capability has a value, meaning inode_killpriv()
* is required, 0 otherwise, meaning inode_killpriv() is not required.
*/
int cap_inode_need_killpriv(struct dentry *dentry)
/**
* cap_inode_killpriv - Erase the security markings on an inode
- * @dentry: The inode/dentry to alter
+ *
+ * @mnt_userns: user namespace of the mount the inode was found from
+ * @dentry: The inode/dentry to alter
*
* Erase the privilege-enhancing security markings on an inode.
*
- * Returns 0 if successful, -ve on error.
+ * If the inode has been found through an idmapped mount the user namespace of
+ * the vfsmount must be passed through @mnt_userns. This function will then
+ * take care to map the inode according to @mnt_userns before checking
+ * permissions. On non-idmapped mounts or if permission checking is to be
+ * performed on the raw inode simply passs init_user_ns.
+ *
+ * Return: 0 if successful, -ve on error.
*/
-int cap_inode_killpriv(struct dentry *dentry)
+int cap_inode_killpriv(struct user_namespace *mnt_userns, struct dentry *dentry)
{
int error;
- error = __vfs_removexattr(dentry, XATTR_NAME_CAPS);
+ error = __vfs_removexattr(mnt_userns, dentry, XATTR_NAME_CAPS);
if (error == -EOPNOTSUPP)
error = 0;
return error;
* by the integrity subsystem, which really wants the unconverted values -
* so that's good.
*/
-int cap_inode_getsecurity(struct inode *inode, const char *name, void **buffer,
+int cap_inode_getsecurity(struct user_namespace *mnt_userns,
+ struct inode *inode, const char *name, void **buffer,
bool alloc)
{
int size, ret;
return -EINVAL;
size = sizeof(struct vfs_ns_cap_data);
- ret = (int) vfs_getxattr_alloc(dentry, XATTR_NAME_CAPS,
- &tmpbuf, size, GFP_NOFS);
+ ret = (int)vfs_getxattr_alloc(mnt_userns, dentry, XATTR_NAME_CAPS,
+ &tmpbuf, size, GFP_NOFS);
dput(dentry);
- if (ret < 0)
+ if (ret < 0 || !tmpbuf)
return ret;
fs_ns = inode->i_sb->s_user_ns;
kroot = make_kuid(fs_ns, root);
+ /* If this is an idmapped mount shift the kuid. */
+ kroot = kuid_into_mnt(mnt_userns, kroot);
+
/* If the root kuid maps to a valid uid in current ns, then return
* this as a nscap. */
mappedroot = from_kuid(current_user_ns(), kroot);
return size;
}
+/**
+ * rootid_from_xattr - translate root uid of vfs caps
+ *
+ * @value: vfs caps value which may be modified by this function
+ * @size: size of @ivalue
+ * @task_ns: user namespace of the caller
+ * @mnt_userns: user namespace of the mount the inode was found from
+ *
+ * If the inode has been found through an idmapped mount the user namespace of
+ * the vfsmount must be passed through @mnt_userns. This function will then
+ * take care to map the inode according to @mnt_userns before checking
+ * permissions. On non-idmapped mounts or if permission checking is to be
+ * performed on the raw inode simply passs init_user_ns.
+ */
static kuid_t rootid_from_xattr(const void *value, size_t size,
- struct user_namespace *task_ns)
+ struct user_namespace *task_ns,
+ struct user_namespace *mnt_userns)
{
const struct vfs_ns_cap_data *nscap = value;
+ kuid_t rootkid;
uid_t rootid = 0;
if (size == XATTR_CAPS_SZ_3)
rootid = le32_to_cpu(nscap->rootid);
- return make_kuid(task_ns, rootid);
+ rootkid = make_kuid(task_ns, rootid);
+ return kuid_from_mnt(mnt_userns, rootkid);
}
static bool validheader(size_t size, const struct vfs_cap_data *cap)
return is_v2header(size, cap) || is_v3header(size, cap);
}
-/*
+/**
+ * cap_convert_nscap - check vfs caps
+ *
+ * @mnt_userns: user namespace of the mount the inode was found from
+ * @dentry: used to retrieve inode to check permissions on
+ * @ivalue: vfs caps value which may be modified by this function
+ * @size: size of @ivalue
+ *
* User requested a write of security.capability. If needed, update the
* xattr to change from v2 to v3, or to fixup the v3 rootid.
*
- * If all is ok, we return the new size, on error return < 0.
+ * If the inode has been found through an idmapped mount the user namespace of
+ * the vfsmount must be passed through @mnt_userns. This function will then
+ * take care to map the inode according to @mnt_userns before checking
+ * permissions. On non-idmapped mounts or if permission checking is to be
+ * performed on the raw inode simply passs init_user_ns.
+ *
+ * Return: On success, return the new size; on error, return < 0.
*/
-int cap_convert_nscap(struct dentry *dentry, const void **ivalue, size_t size)
+int cap_convert_nscap(struct user_namespace *mnt_userns, struct dentry *dentry,
+ const void **ivalue, size_t size)
{
struct vfs_ns_cap_data *nscap;
uid_t nsrootid;
return -EINVAL;
if (!validheader(size, cap))
return -EINVAL;
- if (!capable_wrt_inode_uidgid(inode, CAP_SETFCAP))
+ if (!capable_wrt_inode_uidgid(mnt_userns, inode, CAP_SETFCAP))
return -EPERM;
- if (size == XATTR_CAPS_SZ_2)
+ if (size == XATTR_CAPS_SZ_2 && (mnt_userns == &init_user_ns))
if (ns_capable(inode->i_sb->s_user_ns, CAP_SETFCAP))
/* user is privileged, just write the v2 */
return size;
- rootid = rootid_from_xattr(*ivalue, size, task_ns);
+ rootid = rootid_from_xattr(*ivalue, size, task_ns, mnt_userns);
if (!uid_valid(rootid))
return -EINVAL;
return *effective ? ret : 0;
}
-/*
+/**
+ * get_vfs_caps_from_disk - retrieve vfs caps from disk
+ *
+ * @mnt_userns: user namespace of the mount the inode was found from
+ * @dentry: dentry from which @inode is retrieved
+ * @cpu_caps: vfs capabilities
+ *
* Extract the on-exec-apply capability sets for an executable file.
+ *
+ * If the inode has been found through an idmapped mount the user namespace of
+ * the vfsmount must be passed through @mnt_userns. This function will then
+ * take care to map the inode according to @mnt_userns before checking
+ * permissions. On non-idmapped mounts or if permission checking is to be
+ * performed on the raw inode simply passs init_user_ns.
*/
-int get_vfs_caps_from_disk(const struct dentry *dentry, struct cpu_vfs_cap_data *cpu_caps)
+int get_vfs_caps_from_disk(struct user_namespace *mnt_userns,
+ const struct dentry *dentry,
+ struct cpu_vfs_cap_data *cpu_caps)
{
struct inode *inode = d_backing_inode(dentry);
__u32 magic_etc;
/* Limit the caps to the mounter of the filesystem
* or the more limited uid specified in the xattr.
*/
+ rootkuid = kuid_into_mnt(mnt_userns, rootkuid);
if (!rootid_owns_currentns(rootkuid))
return -ENODATA;
if (!current_in_userns(file->f_path.mnt->mnt_sb->s_user_ns))
return 0;
- rc = get_vfs_caps_from_disk(file->f_path.dentry, &vcaps);
+ rc = get_vfs_caps_from_disk(file_mnt_user_ns(file),
+ file->f_path.dentry, &vcaps);
if (rc < 0) {
if (rc == -EINVAL)
printk(KERN_NOTICE "Invalid argument reading file caps for %s\n",
*
* Set up the proposed credentials for a new execution context being
* constructed by execve(). The proposed creds in @bprm->cred is altered,
- * which won't take effect immediately. Returns 0 if successful, -ve on error.
+ * which won't take effect immediately.
+ *
+ * Return: 0 if successful, -ve on error.
*/
int cap_bprm_creds_from_file(struct linux_binprm *bprm, struct file *file)
{
/**
* cap_inode_removexattr - Determine whether an xattr may be removed
- * @dentry: The inode/dentry being altered
- * @name: The name of the xattr to be changed
+ *
+ * @mnt_userns: User namespace of the mount the inode was found from
+ * @dentry: The inode/dentry being altered
+ * @name: The name of the xattr to be changed
*
* Determine whether an xattr may be removed from an inode, returning 0 if
* permission is granted, -ve if denied.
*
+ * If the inode has been found through an idmapped mount the user namespace of
+ * the vfsmount must be passed through @mnt_userns. This function will then
+ * take care to map the inode according to @mnt_userns before checking
+ * permissions. On non-idmapped mounts or if permission checking is to be
+ * performed on the raw inode simply passs init_user_ns.
+ *
* This is used to make sure security xattrs don't get removed by those who
* aren't privileged to remove them.
*/
-int cap_inode_removexattr(struct dentry *dentry, const char *name)
+int cap_inode_removexattr(struct user_namespace *mnt_userns,
+ struct dentry *dentry, const char *name)
{
struct user_namespace *user_ns = dentry->d_sb->s_user_ns;
struct inode *inode = d_backing_inode(dentry);
if (!inode)
return -EINVAL;
- if (!capable_wrt_inode_uidgid(inode, CAP_SETFCAP))
+ if (!capable_wrt_inode_uidgid(mnt_userns, inode, CAP_SETFCAP))
return -EPERM;
return 0;
}
* @flags: Indications of what has changed
*
* Fix up the results of setuid() call before the credential changes are
- * actually applied, returning 0 to grant the changes, -ve to deny them.
+ * actually applied.
+ *
+ * Return: 0 to grant the changes, -ve to deny them.
*/
int cap_task_fix_setuid(struct cred *new, const struct cred *old, int flags)
{
* @p: The task to affect
*
* Detemine if the requested scheduler policy change is permitted for the
- * specified task, returning 0 if permission is granted, -ve if denied.
+ * specified task.
+ *
+ * Return: 0 if permission is granted, -ve if denied.
*/
int cap_task_setscheduler(struct task_struct *p)
{
}
/**
- * cap_task_ioprio - Detemine if I/O priority change is permitted
+ * cap_task_setioprio - Detemine if I/O priority change is permitted
* @p: The task to affect
* @ioprio: The I/O priority to set
*
* Detemine if the requested I/O priority change is permitted for the specified
- * task, returning 0 if permission is granted, -ve if denied.
+ * task.
+ *
+ * Return: 0 if permission is granted, -ve if denied.
*/
int cap_task_setioprio(struct task_struct *p, int ioprio)
{
}
/**
- * cap_task_ioprio - Detemine if task priority change is permitted
+ * cap_task_setnice - Detemine if task priority change is permitted
* @p: The task to affect
* @nice: The nice value to set
*
* Detemine if the requested task priority change is permitted for the
- * specified task, returning 0 if permission is granted, -ve if denied.
+ * specified task.
+ *
+ * Return: 0 if permission is granted, -ve if denied.
*/
int cap_task_setnice(struct task_struct *p, int nice)
{
/**
* cap_task_prctl - Implement process control functions for this security module
* @option: The process control function requested
- * @arg2, @arg3, @arg4, @arg5: The argument data for this function
+ * @arg2: The argument data for this function
+ * @arg3: The argument data for this function
+ * @arg4: The argument data for this function
+ * @arg5: The argument data for this function
*
* Allow process control functions (sys_prctl()) to alter capabilities; may
* also deny access to other functions not otherwise implemented here.
*
- * Returns 0 or +ve on success, -ENOSYS if this function is not implemented
+ * Return: 0 or +ve on success, -ENOSYS if this function is not implemented
* here, other -ve on error. If -ENOSYS is returned, sys_prctl() and other LSM
* modules will consider performing the function.
*/
* @pages: The size of the mapping
*
* Determine whether the allocation of a new virtual mapping by the current
- * task is permitted, returning 1 if permission is granted, 0 if not.
+ * task is permitted.
+ *
+ * Return: 1 if permission is granted, 0 if not.
*/
int cap_vm_enough_memory(struct mm_struct *mm, long pages)
{
return cap_sys_admin;
}
- /*
+ /**
* cap_mmap_addr - check if able to map given addr
* @addr: address attempting to be mapped
*
* If the process is attempting to map memory below dac_mmap_min_addr they need
* CAP_SYS_RAWIO. The other parameters to this function are unused by the
- * capability security module. Returns 0 if this mapping should be allowed
- * -EPERM if not.
+ * capability security module.
+ *
+ * Return: 0 if this mapping should be allowed or -EPERM if not.
*/
int cap_mmap_addr(unsigned long addr)
{
projects / linux-block.git / commitdiff