]> www.infradead.org Git - users/jedix/linux-maple.git/commit
userns: Don't let unprivileged users trick privileged users into setting the id_map
authorEric W. Biederman <ebiederm@xmission.com>
Sun, 14 Apr 2013 20:47:02 +0000 (13:47 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 25 Apr 2013 19:51:23 +0000 (12:51 -0700)
commitd2b12161ea5208d87dae24bcc5f3fed9da79262e
treeb1fe0dbb9d53fc27cdf348b6d91a2a80084b3dec
parent73f25feefdcc89cce395b86e135e0936cbd2c7ae
userns: Don't let unprivileged users trick privileged users into setting the id_map

commit 6708075f104c3c9b04b23336bb0366ca30c3931b upstream.

When we require privilege for setting /proc/<pid>/uid_map or
/proc/<pid>/gid_map no longer allow an unprivileged user to
open the file and pass it to a privileged program to write
to the file.

Instead when privilege is required require both the opener and the
writer to have the necessary capabilities.

I have tested this code and verified that setting /proc/<pid>/uid_map
fails when an unprivileged user opens the file and a privielged user
attempts to set the mapping, that unprivileged users can still map
their own id, and that a privileged users can still setup an arbitrary
mapping.

Reported-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
kernel/user_namespace.c