Messages in this thread | | | Date | Thu, 4 Jun 2015 17:03:01 -0500 | From | "Serge E. Hallyn" <> | Subject | Re: [PATCH v3 2/2] capabilities: Add a securebit to disable PR_CAP_AMBIENT_RAISE |
| |
On Wed, May 27, 2015 at 04:47:59PM -0700, Andy Lutomirski wrote: > Per Andrew Morgan's request, add a securebit to allow admins to > disable PR_CAP_AMBIENT_RAISE. This securebit will prevent processes > from adding capabilities to their ambient set. > > For simplicity, this disables PR_CAP_AMBIENT_RAISE entirely rather > than just disabling setting previously cleared bits. > > Acked-By: Andrew G. Morgan <morgan@kernel.org> > Cc: Kees Cook <keescook@chromium.org> > Cc: Christoph Lameter <cl@linux.com> > Cc: Serge Hallyn <serge.hallyn@canonical.com>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
> Cc: Andy Lutomirski <luto@amacapital.net> > Cc: Jonathan Corbet <corbet@lwn.net> > Cc: Aaron Jones <aaronmdjones@gmail.com> > CC: Ted Ts'o <tytso@mit.edu> > Cc: linux-security-module@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > Cc: linux-api@vger.kernel.org > Cc: akpm@linuxfoundation.org > Cc: Andrew G. Morgan <morgan@kernel.org> > Cc: Mimi Zohar <zohar@linux.vnet.ibm.com> > Cc: Austin S Hemmelgarn <ahferroin7@gmail.com> > Cc: Markku Savela <msa@moth.iki.fi> > Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> > Cc: Michael Kerrisk <mtk.manpages@gmail.com> > Signed-off-by: Andy Lutomirski <luto@kernel.org> > --- > include/uapi/linux/securebits.h | 11 ++++++++++- > security/commoncap.c | 3 ++- > 2 files changed, 12 insertions(+), 2 deletions(-) > > diff --git a/include/uapi/linux/securebits.h b/include/uapi/linux/securebits.h > index 985aac9e6bf8..35ac35cef217 100644 > --- a/include/uapi/linux/securebits.h > +++ b/include/uapi/linux/securebits.h > @@ -43,9 +43,18 @@ > #define SECBIT_KEEP_CAPS (issecure_mask(SECURE_KEEP_CAPS)) > #define SECBIT_KEEP_CAPS_LOCKED (issecure_mask(SECURE_KEEP_CAPS_LOCKED)) > > +/* When set, a process cannot add new capabilities to its ambient set. */ > +#define SECURE_NO_CAP_AMBIENT_RAISE 6 > +#define SECURE_NO_CAP_AMBIENT_RAISE_LOCKED 7 /* make bit-6 immutable */ > + > +#define SECBIT_NO_CAP_AMBIENT_RAISE (issecure_mask(SECURE_NO_CAP_AMBIENT_RAISE)) > +#define SECBIT_NO_CAP_AMBIENT_RAISE_LOCKED \ > + (issecure_mask(SECURE_NO_CAP_AMBIENT_RAISE_LOCKED)) > + > #define SECURE_ALL_BITS (issecure_mask(SECURE_NOROOT) | \ > issecure_mask(SECURE_NO_SETUID_FIXUP) | \ > - issecure_mask(SECURE_KEEP_CAPS)) > + issecure_mask(SECURE_KEEP_CAPS) | \ > + issecure_mask(SECURE_NO_CAP_AMBIENT_RAISE)) > #define SECURE_ALL_LOCKS (SECURE_ALL_BITS << 1) > > #endif /* _UAPI_LINUX_SECUREBITS_H */ > diff --git a/security/commoncap.c b/security/commoncap.c > index 835a7584f7ea..22b7b91c5eae 100644 > --- a/security/commoncap.c > +++ b/security/commoncap.c > @@ -987,7 +987,8 @@ int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3, > if (arg2 == PR_CAP_AMBIENT_RAISE && > (!cap_raised(current_cred()->cap_permitted, arg3) || > !cap_raised(current_cred()->cap_inheritable, > - arg3))) > + arg3) || > + issecure(SECURE_NO_CAP_AMBIENT_RAISE))) > return -EPERM; > > new = prepare_creds(); > -- > 2.1.0 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/
| |