MLK-9769-10 Add Blob command bitdefs.

[karo-tx-linux.git] / fs / namespace.c

diff --git a/fs/namespace.c b/fs/namespace.c
index 75536db4b69bca37e37c4997164c34527c0192e5..039f3802d70efed3d5e2b5efea811dde3d41e69d 100644 (file)
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1295,6 +1295,8 @@ void umount_tree(struct mount *mnt, int how)
        }
        if (last) {
                last->mnt_hash.next = unmounted.first;
+               if (unmounted.first)
+                       unmounted.first->pprev = &last->mnt_hash.next;
                unmounted.first = tmp_list.first;
                unmounted.first->pprev = &unmounted.first;
        }
@@ -1365,6 +1367,8 @@ static int do_umount(struct mount *mnt, int flags)
                 * Special case for "unmounting" root ...
                 * we just try to remount it readonly.
                 */
+               if (!capable(CAP_SYS_ADMIN))
+                       return -EPERM;
                down_write(&sb->s_umount);
                if (!(sb->s_flags & MS_RDONLY))
                        retval = do_remount_sb(sb, MS_RDONLY, NULL, 0);
@@ -1437,6 +1441,9 @@ SYSCALL_DEFINE2(umount, char __user *, name, int, flags)
                goto dput_and_out;
        if (mnt->mnt.mnt_flags & MNT_LOCKED)
                goto dput_and_out;
+       retval = -EPERM;
+       if (flags & MNT_FORCE && !capable(CAP_SYS_ADMIN))
+               goto dput_and_out;
 
        retval = do_umount(mnt, flags);
 dput_and_out:
@@ -1962,7 +1969,13 @@ static int do_remount(struct path *path, int flags, int mnt_flags,
        }
        if ((mnt->mnt.mnt_flags & MNT_LOCK_NODEV) &&
            !(mnt_flags & MNT_NODEV)) {
-               return -EPERM;
+               /* Was the nodev implicitly added in mount? */
+               if ((mnt->mnt_ns->user_ns != &init_user_ns) &&
+                   !(sb->s_type->fs_flags & FS_USERNS_DEV_MOUNT)) {
+                       mnt_flags |= MNT_NODEV;
+               } else {
+                       return -EPERM;
+               }
        }
        if ((mnt->mnt.mnt_flags & MNT_LOCK_NOSUID) &&
            !(mnt_flags & MNT_NOSUID)) {
@@ -2829,6 +2842,9 @@ SYSCALL_DEFINE2(pivot_root, const char __user *, new_root,
        /* make sure we can reach put_old from new_root */
        if (!is_path_reachable(old_mnt, old.dentry, &new))
                goto out4;
+       /* make certain new is below the root */
+       if (!is_path_reachable(new_mnt, new.dentry, &root))
+               goto out4;
        root_mp->m_count++; /* pin it so it won't go away */
        lock_mount_hash();
        detach_mnt(new_mnt, &parent_path);