mnt: Fix fs_fully_visible to verify the root directory is visible

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.

Cc: [email protected]
Reported-by: Eric Windisch <[email protected]>
Signed-off-by: "Eric W. Biederman" <[email protected]>
This commit is contained in:
Eric W. Biederman 2015-05-08 16:36:50 -05:00
commit 7e96c1b0e0

View file

@ -3179,6 +3179,12 @@ 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.
*/