[PATCH review 5/6] userns: Allow the userns root to mount ramfs.

Eric W. Biederman ebiederm at xmission.com
Sat Jan 26 02:26:11 UTC 2013


There is no backing store to ramfs and file creation
rules are the same as for any other filesystem so
it is semantically safe to allow unprivileged users
to mount it.

The memory control group successfully limits how much
memory ramfs can consume on any system that cares about
a user namespace root using ramfs to exhaust memory
the memory control group can be deployed.

Signed-off-by: "Eric W. Biederman" <ebiederm at xmission.com>
---
 fs/ramfs/inode.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/fs/ramfs/inode.c b/fs/ramfs/inode.c
index eab8c09..c24f1e1 100644
--- a/fs/ramfs/inode.c
+++ b/fs/ramfs/inode.c
@@ -260,6 +260,7 @@ static struct file_system_type ramfs_fs_type = {
 	.name		= "ramfs",
 	.mount		= ramfs_mount,
 	.kill_sb	= ramfs_kill_sb,
+	.fs_flags	= FS_USERNS_MOUNT,
 };
 static struct file_system_type rootfs_fs_type = {
 	.name		= "rootfs",
-- 
1.7.5.4



More information about the Containers mailing list