diff options
| -rw-r--r-- | fs/devpts/inode.c | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/fs/devpts/inode.c b/fs/devpts/inode.c index 472e6befc54d..073d30b9d1ac 100644 --- a/fs/devpts/inode.c +++ b/fs/devpts/inode.c @@ -243,6 +243,13 @@ static int mknod_ptmx(struct super_block *sb) struct dentry *root = sb->s_root; struct pts_fs_info *fsi = DEVPTS_SB(sb); struct pts_mount_opts *opts = &fsi->mount_opts; + kuid_t root_uid; + kgid_t root_gid; + + root_uid = make_kuid(current_user_ns(), 0); + root_gid = make_kgid(current_user_ns(), 0); + if (!uid_valid(root_uid) || !gid_valid(root_gid)) + return -EINVAL; mutex_lock(&root->d_inode->i_mutex); @@ -273,6 +280,8 @@ static int mknod_ptmx(struct super_block *sb) mode = S_IFCHR|opts->ptmxmode; init_special_inode(inode, mode, MKDEV(TTYAUX_MAJOR, 2)); + inode->i_uid = root_uid; + inode->i_gid = root_gid; d_add(dentry, inode); @@ -438,6 +447,12 @@ static struct dentry *devpts_mount(struct file_system_type *fs_type, if (error) return ERR_PTR(error); + /* Require newinstance for all user namespace mounts to ensure + * the mount options are not changed. + */ + if ((current_user_ns() != &init_user_ns) && !opts.newinstance) + return ERR_PTR(-EINVAL); + if (opts.newinstance) s = sget(fs_type, NULL, set_anon_super, flags, NULL); else @@ -491,6 +506,9 @@ static struct file_system_type devpts_fs_type = { .name = "devpts", .mount = devpts_mount, .kill_sb = devpts_kill_sb, +#ifdef CONFIG_DEVPTS_MULTIPLE_INSTANCES + .fs_flags = FS_USERNS_MOUNT | FS_USERNS_DEV_MOUNT, +#endif }; /* |