From f8cf2bd9dfe7b3f22435bd884bfeb555ae62652c Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Fri, 8 May 2015 16:36:50 -0500 Subject: mnt: Fix fs_fully_visible to verify the root directory is visible commit 7e96c1b0e0f495c5a7450dc4aa7c9a24ba4305bd upstream. This fixes a dumb bug in fs_fully_visible that allows proc or sys to be mounted if there is a bind mount of part of /proc/ or /sys/ visible. Reported-by: Eric Windisch Signed-off-by: "Eric W. Biederman" Signed-off-by: Greg Kroah-Hartman --- fs/namespace.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'fs') diff --git a/fs/namespace.c b/fs/namespace.c index 4622ee32a5e2..38ed1e1bed41 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -3178,6 +3178,12 @@ bool fs_fully_visible(struct file_system_type *type) if (mnt->mnt.mnt_sb->s_type != type) continue; + /* This mount is not fully visible if it's root directory + * is not the root directory of the filesystem. + */ + if (mnt->mnt.mnt_root != mnt->mnt.mnt_sb->s_root) + continue; + /* This mount is not fully visible if there are any child mounts * that cover anything except for empty directories. */ -- cgit v1.2.3