]> git.hungrycats.org Git - linux/commitdiff
mnt: Fix fs_fully_visible to verify the root directory is visible
authorEric W. Biederman <ebiederm@xmission.com>
Fri, 8 May 2015 21:36:50 +0000 (16:36 -0500)
committerJiri Slaby <jslaby@suse.cz>
Sat, 16 May 2015 07:12:43 +0000 (09:12 +0200)
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 <ewindisch@docker.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
fs/namespace.c

index 7c3c0f6d274451d2964b79ad54db84d149ec2d71..247f34d43dda4e22f9516b16c3853167f7a17c3f 100644 (file)
@@ -2940,6 +2940,12 @@ 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.
                 */