From e51db73532955dc5eaba4235e62b74b460709d5b Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Sat, 30 Mar 2013 19:57:41 -0700 Subject: userns: Better restrictions on when proc and sysfs can be mounted Rely on the fact that another flavor of the filesystem is already mounted and do not rely on state in the user namespace. Verify that the mounted filesystem is not covered in any significant way. I would love to verify that the previously mounted filesystem has no mounts on top but there are at least the directories /proc/sys/fs/binfmt_misc and /sys/fs/cgroup/ that exist explicitly for other filesystems to mount on top of. Refactor the test into a function named fs_fully_visible and call that function from the mount routines of proc and sysfs. This makes this test local to the filesystems involved and the results current of when the mounts take place, removing a weird threading of the user namespace, the mount namespace and the filesystems themselves. Signed-off-by: "Eric W. Biederman" --- kernel/user_namespace.c | 2 -- 1 file changed, 2 deletions(-) (limited to 'kernel/user_namespace.c') diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c index d8c30db06c5..d58ad1e7a79 100644 --- a/kernel/user_namespace.c +++ b/kernel/user_namespace.c @@ -97,8 +97,6 @@ int create_user_ns(struct cred *new) set_cred_user_ns(new, ns); - update_mnt_policy(ns); - return 0; } -- cgit v1.2.3-18-g5258