From aee1c13dd0f6c2fc56e0e492b349ee8ac655880f Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Mon, 25 Mar 2013 19:57:10 -0700 Subject: [PATCH] proc: Restrict mounting the proc filesystem Don't allow mounting the proc filesystem unless the caller has CAP_SYS_ADMIN rights over the pid namespace. The principle here is if you create or have capabilities over it you can mount it, otherwise you get to live with what other people have mounted. Andy pointed out that this is needed to prevent users in a user namespace from remounting proc and specifying different hidepid and gid options on already existing proc mounts. Cc: stable@vger.kernel.org Reported-by: Andy Lutomirski Signed-off-by: "Eric W. Biederman" --- fs/proc/root.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/proc/root.c b/fs/proc/root.c index 229e366598da..38bd5d423fcd 100644 --- a/fs/proc/root.c +++ b/fs/proc/root.c @@ -110,7 +110,8 @@ static struct dentry *proc_mount(struct file_system_type *fs_type, ns = task_active_pid_ns(current); options = data; - if (!current_user_ns()->may_mount_proc) + if (!current_user_ns()->may_mount_proc || + !ns_capable(ns->user_ns, CAP_SYS_ADMIN)) return ERR_PTR(-EPERM); } -- 2.20.1