[Devel] [PATCH vz10 1/2] fs: allow non-init s_user_ns for filesystems with FS_VE_MOUNT

[Aleksei Oladko]

Mounting from non-init user namespaces for filesystems without
FS_USERNS_MOUNT was prohibited by commit e1c5ae59c0f22.

The new flag FS_VE_MOUNT was introduced in commit c0e4e73052f89
to allow mounting such filesystems inside container user
namespaces.

https://virtuozzo.atlassian.net/browse/VSTOR-105978

Signed-off-by: Aleksei Oladko <aleksey.oladko at virtuozzo.com>
---
 fs/super.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/super.c b/fs/super.c
index 93b125ebd4e3..b8da7df103b3 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -778,7 +778,8 @@ struct super_block *sget_fc(struct fs_context *fc,
 	 * This can happen when fsconfig() is called from init_user_ns with
 	 * an fs_fd opened in another user namespace.
 	 */
-	if (user_ns != &init_user_ns && !(fc->fs_type->fs_flags & FS_USERNS_MOUNT)) {
+	if (user_ns != &init_user_ns && !(fc->fs_type->fs_flags & FS_USERNS_MOUNT ||
+				fc->fs_type->fs_flags & FS_VE_MOUNT)) {
 		errorfc(fc, "VFS: Mounting from non-initial user namespace is not allowed");
 		return ERR_PTR(-EPERM);
 	}
-- 
2.43.0