diff options
| author | Eric W. Biederman <ebiederm@xmission.com> | 2015-01-07 08:10:09 -0600 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-07-10 09:45:43 -0700 |
| commit | 0cf10d95efb24cd901897c87218d6fc5dfc735dc (patch) | |
| tree | 7f94a7140e960b03552ed71cbd51607883ad01e3 | |
| parent | b0989d29acab6d7c6d6c8d3e89979b9514253995 (diff) | |
| download | lwn-0cf10d95efb24cd901897c87218d6fc5dfc735dc.tar.gz lwn-0cf10d95efb24cd901897c87218d6fc5dfc735dc.zip | |
vfs: Ignore unlocked mounts in fs_fully_visible
commit ceeb0e5d39fcdf4dca2c997bf225c7fc49200b37 upstream.
Limit the mounts fs_fully_visible considers to locked mounts.
Unlocked can always be unmounted so considering them adds hassle
but no security benefit.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/namespace.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/fs/namespace.c b/fs/namespace.c index 13b0f7bfc096..f07c7691ace1 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -3187,11 +3187,15 @@ bool fs_fully_visible(struct file_system_type *type) 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. + /* This mount is not fully visible if there are any + * locked child mounts that cover anything except for + * empty directories. */ list_for_each_entry(child, &mnt->mnt_mounts, mnt_child) { struct inode *inode = child->mnt_mountpoint->d_inode; + /* Only worry about locked mounts */ + if (!(mnt->mnt.mnt_flags & MNT_LOCKED)) + continue; if (!S_ISDIR(inode->i_mode)) goto next; if (inode->i_nlink > 2) |