On 4/21/19 1:31 PM, Casey Schaufler wrote:
On 4/19/2019 8:27 AM, Stephen Smalley wrote:
On 4/18/19 8:44 PM, Casey Schaufler wrote:
This patchset provides the changes required for
the any security module to stack safely with any other.
A new process attribute identifies which security module
information should be reported by SO_PEERSEC and the
/proc/.../attr/current interface. This is provided by
/proc/.../attr/display. Writing the name of the security
module desired to this interface will set which LSM hooks
will be called for this information. The first security
module providing the hooks will be used by default.
The use of integer based security tokens (secids) is
generally (but not completely) replaced by a structure
lsm_export. The lsm_export structure can contain information
for each of the security modules that export information
outside the LSM layer.
The LSM interfaces that provide "secctx" text strings
have been changed to use a structure "lsm_context"
instead of a pointer/length pair. In some cases the
interfaces used a "char *" pointer and in others a
"void *". This was necessary to ensure that the correct
release mechanism for the text is used. It also makes
many of the interfaces cleaner.
Security modules that use Netlabel must agree on the
labels to be used on outgoing packets. If the modules
do not agree on the label option to be used the operation
will fail.
Netfilter secmarks are restricted to a single security
module. The first module using the facility will "own"
the secmarks.
Is it expected that enabling all security modules with this change
will yield permission denials on packet send/receive (e.g. sendmsg()
fails with permission denied), even without any configuration of
NetLabel or SECMARK? That's what I see.
Yes.
Smack is much more aggressive about using labeled networking
than SELinux. Smack tells Netlabel to label networks, whereas
SELinux expects them to be unlabeled. Smack has the concept of
an "ambient" label, which is applied to unlabeled packets, and
for which packets are sent unlabeled. SELinux only uses netlabel
for the MLS component, whereas Smack uses it for the entire
label. In short, it's amazing if there's a case where they do
agree.
You can make the default configuration work better by specifying
that the Smack "floor" label be treated more like the unconfined_t.
# echo _ 0 0 0 > /sys/fs/smackfs/cipso2
# echo NotFloor > /sys/fs/smackfs/ambient
Will result in a situation where the two MAC systems will agree
much more often.
Not sure that should be required given that SELinux doesn't enable
labeled networking at all by default, so there is no real conflict
until/unless someone configures labeled networking for SELinux. I'll
defer to Paul on that question.
Given this restriction, to what extent have you tested Smack+SELinux
together and what worked and didn't work? Everything except for
networking-related tests?
git://github.com/cschaufler/lsm-stacking.git#stack-5.1-v2-full
Signed-off-by: Casey Schaufler <casey@xxxxxxxxxxxxxxxx>
---
drivers/android/binder.c | 25 +-
fs/kernfs/dir.c | 6 +-
fs/kernfs/inode.c | 31 +-
fs/kernfs/kernfs-internal.h | 3 +-
fs/nfs/inode.c | 13 +-
fs/nfs/internal.h | 8 +-
fs/nfs/nfs4proc.c | 17 +-
fs/nfs/nfs4xdr.c | 16 +-
fs/nfsd/nfs4proc.c | 8 +-
fs/nfsd/nfs4xdr.c | 14 +-
fs/nfsd/vfs.c | 7 +-
fs/proc/base.c | 1 +
include/linux/cred.h | 3 +-
include/linux/lsm_hooks.h | 119 +++---
include/linux/nfs4.h | 8 +-
include/linux/security.h | 159 ++++++--
include/net/af_unix.h | 2 +-
include/net/netlabel.h | 18 +-
include/net/scm.h | 14 +-
kernel/audit.c | 43 +--
kernel/audit.h | 9 +-
kernel/auditfilter.c | 6 +-
kernel/auditsc.c | 77 ++--
kernel/cred.c | 15 +-
net/ipv4/cipso_ipv4.c | 13 +-
net/ipv4/ip_sockglue.c | 14 +-
net/netfilter/nf_conntrack_netlink.c | 29 +-
net/netfilter/nf_conntrack_standalone.c | 16 +-
net/netfilter/nfnetlink_queue.c | 35 +-
net/netfilter/nft_meta.c | 8 +-
net/netfilter/xt_SECMARK.c | 9 +-
net/netlabel/netlabel_kapi.c | 125 ++++--
net/netlabel/netlabel_unlabeled.c | 101 +++--
net/netlabel/netlabel_unlabeled.h | 2 +-
net/netlabel/netlabel_user.c | 13 +-
net/netlabel/netlabel_user.h | 2 +-
net/unix/af_unix.c | 6 +-
security/apparmor/audit.c | 4 +-
security/apparmor/include/audit.h | 2 +-
security/apparmor/include/net.h | 6 +-
security/apparmor/include/secid.h | 9 +-
security/apparmor/lsm.c | 64 ++--
security/apparmor/secid.c | 42 +-
security/integrity/ima/ima.h | 14 +-
security/integrity/ima/ima_api.c | 9 +-
security/integrity/ima/ima_appraise.c | 6 +-
security/integrity/ima/ima_main.c | 34 +-
security/integrity/ima/ima_policy.c | 19 +-
security/security.c | 653
+++++++++++++++++++++++++++-----
security/selinux/hooks.c | 310 +++++++--------
security/selinux/include/audit.h | 5 +-
security/selinux/include/netlabel.h | 7 +
security/selinux/include/objsec.h | 43 ++-
security/selinux/netlabel.c | 69 ++--
security/selinux/ss/services.c | 18 +-
security/smack/smack.h | 34 ++
security/smack/smack_access.c | 14 +-
security/smack/smack_lsm.c | 388 ++++++++++---------
security/smack/smack_netfilter.c | 48 ++-
security/smack/smackfs.c | 23 +-
60 files changed, 1855 insertions(+), 961 deletions(-)
