From a001e74cef34d95ede6535ef521011c612657a3a Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Mon, 6 Jun 2016 15:48:04 -0500 Subject: [PATCH] mnt: Move the FS_USERNS_MOUNT check into sget_userns Allowing a filesystem to be mounted by other than root in the initial user namespace is a filesystem property not a mount namespace property and as such should be checked in filesystem specific code. Move the FS_USERNS_MOUNT test into super.c:sget_userns(). Acked-by: Seth Forshee Signed-off-by: "Eric W. Biederman" --- fs/namespace.c | 4 ---- fs/super.c | 4 ++++ 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/fs/namespace.c b/fs/namespace.c index 1a69aa786975..2e13f6cfe5df 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -2397,10 +2397,6 @@ static int do_new_mount(struct path *path, const char *fstype, int flags, return -ENODEV; if (user_ns != &init_user_ns) { - if (!(type->fs_flags & FS_USERNS_MOUNT)) { - put_filesystem(type); - return -EPERM; - } /* Only in special cases allow devices from mounts * created outside the initial user namespace. */ diff --git a/fs/super.c b/fs/super.c index 874c7e3ebb8f..78790ada7191 100644 --- a/fs/super.c +++ b/fs/super.c @@ -466,6 +466,10 @@ struct super_block *sget_userns(struct file_system_type *type, struct super_block *old; int err; + if (!(flags & MS_KERNMOUNT) && + !(type->fs_flags & FS_USERNS_MOUNT) && + !capable(CAP_SYS_ADMIN)) + return ERR_PTR(-EPERM); retry: spin_lock(&sb_lock); if (test) { -- 2.45.2