Your message dated Thu, 13 Oct 2016 17:00:39 +0200
with message-id <>
and subject line Bug housekeeping
has caused the Debian Bug report #838958,
regarding linux: mount(2) _silently_ ignores other mountflags when MS_BIND is 
to be marked as done.

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--- Begin Message ---
Source: linux
Severity: important
Tags: upstream

>From the mount(2) man page:

    MS_BIND (Linux 2.4 onward)
        Perform a bind mount, making a file or a directory subtree visible at
        another point within a filesystem. Bind mounts may cross filesystem
        boundaries and span chroot(2) jails. The filesystemtype and data
        arguments are ignored. Up until Linux 2.6.26, mountflags was also
        ignored (the bind mount has the same mount options as the underlying
        mount point).

Apparently, this applies to recent kernels too (at least 3.16).

Silently ignoring user-specified flags can open security holes, e.g. when
a sysadm bind-mounts a filesystem for use by a containter, thinking the mount
will be read-only:

# mount -o bind,ro /usr /containers/X/usr

Despite mount returning successfully, container X has /usr mounted
read/write, and root inside the container can easily corrupt/subvert
the host system.

Please keep in mind that recent versions of mount(1) work around the bug, by
calling mount() twice (once with the "bind" flag, then with the other flags),
but other applications calling mount() directly are usually affected.

Best regards,

-- System Information:
Debian Release: 8.6
  APT prefers stable
  APT policy: (500, 'stable')
Architecture: i386 (i686)

Kernel: Linux 3.16.0-4-686-pae (SMP w/1 CPU core)
Locale: LANG=C, LC_CTYPE=C (charmap=ANSI_X3.4-1968)
Shell: /bin/sh linked to /bin/dash
Init: sysvinit (via /sbin/init)

--- End Message ---
--- Begin Message ---
Version: 4.08-1


this bug should be fixed with the latest upload of manpages.


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