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().
Signed-off-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
---
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) {
--
2.8.3
--
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