Map the permission gating RTM_GETNEIGH/RTM_GETNEIGHTBL messages to a
new permission so that it can be distinguished from the other netlink
route permissions in selinux policy. The new permission is triggered by
a flag set in system images T and up.
This change is intended to be backported to all kernels that a T system
image can run on top of.
Bug: 171572148
Test: atest NetworkInterfaceTest
Test: atest CtsSelinuxTargetSdkCurrentTestCases
Test: atest bionic-unit-tests-static
Test: On Cuttlefish, run combinations of:
- Policy bit set or omitted (see https://r.android.com/1701847)
- This patch applied or omitted
- App having nlmsg_readneigh permission or not
Verify that only the combination of this patch + the policy bit being
set + the app not having the nlmsg_readneigh permission prevents the
app from sending RTM_GETNEIGH messages.
Change-Id: I4bcfce4decb34ea9388eeedfc4be67403de8a980
Signed-off-by: Bram Bonné <brambonne@google.com>
(cherry picked from commit fac07550bdac9adea0dbe3edbdbec7a9a690a178)
(cherry picked from commit 32d7afd1472c3cce509a3455b40a575540eac780)
Map the permission gating RTM_GETLINK messages to a new permission so
that it can be distinguished from the other netlink route permissions
in selinux policy.
This is a temporary Android-only patch that will be deprecated in
newer kernels once the long-term solution lands as discusssed on the
mailing list [1]. The maintainer's recommended solution is more
general, much more complex, and likely not suitable for backporting.
This patch provides the minimal change needed for Android including
the userspace settable trigger which ensures that the permission
change is only applied to the newest version of Android which
contains the changes needed for userpace compatibility.
[1]: https://lore.kernel.org/selinux/20200116142653.61738-1-jeffv@google.com/
Bug: 141455849
Bug: 148218425
Test: CtsSelinuxTargetSdkCurrentTestCases
Test: atest bionic-unit-tests-static
Test: atest NetworkInterfaceTest
Test: Connect to Wi-Fi network
Test: Set up hotspot
Test: Cast from device
Test: Pair Bluetooth device
Test: Call getifaddrs() directly from within an app.
Test: Call NetworkInterface#getNetworkInterfaces() from within an app.
Change-Id: I7b44ce60ad98f858c412722d41b9842f8577151f
Signed-off-by: Jeff Vander Stoep <jeffv@google.com>
Implement the actual checks introduced to eBPF related syscalls. This
implementation use the security field inside bpf object to store a sid that
identify the bpf object. And when processes try to access the object,
selinux will check if processes have the right privileges. The creation
of eBPF object are also checked at the general bpf check hook and new
cmd introduced to eBPF domain can also be checked there.
Signed-off-by: Chenbo Feng <fengc@google.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: James Morris <james.l.morris@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry-pick from net-next: ec27c3568a34c7fe5fcf4ac0a354eda77687f7eb)
Bug: 30950746
Change-Id: Ifb0cdd4b7d470223b143646b339ba511ac77c156
Distinguish capability checks against a target associated
with the init user namespace versus capability checks against
a target associated with a non-init user namespace by defining
and using separate security classes for the latter.
This is needed to support e.g. Chrome usage of user namespaces
for the Chrome sandbox without needing to allow Chrome to also
exercise capabilities on targets in the init user namespace.
Suggested-by: Dan Walsh <dwalsh@redhat.com>
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Utilize existing kernel_read_file hook on kernel module load.
Add module_load permission to the system class.
Enforces restrictions on kernel module origin when calling the
finit_module syscall. The hook checks that source type has
permission module_load for the target type.
Example for finit_module:
allow foo bar_file:system module_load;
Similarly restrictions are enforced on kernel module loading when
calling the init_module syscall. The hook checks that source
type has permission module_load with itself as the target object
because the kernel module is sourced from the calling process.
Example for init_module:
allow foo foo:system module_load;
Signed-off-by: Jeff Vander Stoep <jeffv@google.com>
[PM: fixed return value of selinux_kernel_read_file()]
Signed-off-by: Paul Moore <paul@paul-moore.com>
Make validatetrans decisions available through selinuxfs.
"/validatetrans" is added to selinuxfs for this purpose.
This functionality is needed by file system servers
implemented in userspace or kernelspace without the VFS
layer.
Writing "$oldcontext $newcontext $tclass $taskcontext"
to /validatetrans is expected to return 0 if the transition
is allowed and -EPERM otherwise.
Signed-off-by: Andrew Perepechko <anserper@ya.ru>
CC: andrew.perepechko@seagate.com
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <pmoore@redhat.com>
Remove unused permission definitions from SELinux.
Many of these were only ever used in pre-mainline
versions of SELinux, prior to Linux 2.6.0. Some of them
were used in the legacy network or compat_net=1 checks
that were disabled by default in Linux 2.6.18 and
fully removed in Linux 2.6.30.
Permissions never used in mainline Linux:
file swapon
filesystem transition
tcp_socket { connectto newconn acceptfrom }
node enforce_dest
unix_stream_socket { newconn acceptfrom }
Legacy network checks, removed in 2.6.30:
socket { recv_msg send_msg }
node { tcp_recv tcp_send udp_recv udp_send rawip_recv rawip_send dccp_recv dccp_send }
netif { tcp_recv tcp_send udp_recv udp_send rawip_recv rawip_send dccp_recv dccp_send }
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <pmoore@redhat.com>
Update the set of SELinux netlink socket class definitions to match
the set of netlink protocols implemented by the kernel. The
ip_queue implementation for the NETLINK_FIREWALL and NETLINK_IP6_FW protocols
was removed in d16cf20e2f, so we can remove
the corresponding class definitions as this is dead code. Add new
classes for NETLINK_ISCSI, NETLINK_FIB_LOOKUP, NETLINK_CONNECTOR,
NETLINK_NETFILTER, NETLINK_GENERIC, NETLINK_SCSITRANSPORT, NETLINK_RDMA,
and NETLINK_CRYPTO so that we can distinguish among sockets created
for each of these protocols. This change does not define the finer-grained
nlsmsg_read/write permissions or map specific nlmsg_type values to those
permissions in the SELinux nlmsgtab; if finer-grained control of these
sockets is desired/required, that can be added as a follow-on change.
We do not define a SELinux class for NETLINK_ECRYPTFS as the implementation
was removed in 624ae52845.
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <pmoore@redhat.com>
Add security hooks to the binder and implement the hooks for SELinux.
The security hooks enable security modules such as SELinux to implement
controls over binder IPC. The security hooks include support for
controlling what process can become the binder context manager
(binder_set_context_mgr), controlling the ability of a process
to invoke a binder transaction/IPC to another process (binder_transaction),
controlling the ability of a process to transfer a binder reference to
another process (binder_transfer_binder), and controlling the ability
of a process to transfer an open file to another process (binder_transfer_file).
These hooks have been included in the Android kernel trees since Android 4.3.
(Updated to reflect upstream relocation and changes to the binder driver,
changes to the LSM audit data structures, coding style cleanups, and
to add inline documentation for the hooks).
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Nick Kralevich <nnk@google.com>
Acked-by: Jeffrey Vander Stoep <jeffv@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Register a netlink per-protocol bind fuction for audit to check userspace
process capabilities before allowing a multicast group connection.
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a new permission to align with the new TUN multiqueue support,
"tun_socket:attach_queue".
The corresponding SELinux reference policy patch is show below:
diff --git a/policy/flask/access_vectors b/policy/flask/access_vectors
index 28802c5..a0664a1 100644
--- a/policy/flask/access_vectors
+++ b/policy/flask/access_vectors
@@ -827,6 +827,9 @@ class kernel_service
class tun_socket
inherits socket
+{
+ attach_queue
+}
class x_pointer
inherits x_device
Signed-off-by: Paul Moore <pmoore@redhat.com>
Acked-by: Eric Paris <eparis@parisplace.org>
Tested-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull SELinux regression fixes from James Morris.
Andrew Morton has a box that hit that open perms problem.
I also renamed the "epollwakeup" selinux name for the new capability to
be "block_suspend", to match the rename done by commit d9914cf661
("PM: Rename CAP_EPOLLWAKEUP to CAP_BLOCK_SUSPEND").
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
SELinux: do not check open perms if they are not known to policy
SELinux: include definition of new capabilities
The kernel has added CAP_WAKE_ALARM and CAP_EPOLLWAKEUP. We need to
define these in SELinux so they can be mediated by policy.
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
The security_is_socket_class() is auto-generated by genheaders based
on classmap.h to reduce maintenance effort when a new class is defined
in SELinux kernel. The name for any socket class should be suffixed by
"socket" and doesn't contain more than one substr of "socket".
Signed-off-by: Harry Ciao <qingtao.cao@windriver.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
These permissions are not used and can be dropped in the kernel
definitions.
Suggested-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Privileged syslog operations currently require CAP_SYS_ADMIN. Split
this off into a new CAP_SYSLOG privilege which we can sanely take away
from a container through the capability bounding set.
With this patch, an lxc container can be prevented from messing with
the host's syslog (i.e. dmesg -c).
Changelog: mar 12 2010: add selinux capability2:cap_syslog perm
Changelog: nov 22 2010:
. port to new kernel
. add a WARN_ONCE if userspace isn't using CAP_SYSLOG
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Acked-by: Andrew G. Morgan <morgan@kernel.org>
Acked-By: Kees Cook <kees.cook@canonical.com>
Cc: James Morris <jmorris@namei.org>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: "Christopher J. PeBenito" <cpebenito@tresys.com>
Cc: Eric Paris <eparis@parisplace.org>
Signed-off-by: James Morris <jmorris@namei.org>
There is interest in being able to see what the actual policy is that was
loaded into the kernel. The patch creates a new selinuxfs file
/selinux/policy which can be read by userspace. The actual policy that is
loaded into the kernel will be written back out to userspace.
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
execmod "could" show up on non regular files and non chr files. The current
implementation would actually make these checks against non-existant bits
since the code assumes the execmod permission is same for all file types.
To make this line up for chr files we had to define execute_no_trans and
entrypoint permissions. These permissions are unreachable and only existed
to to make FILE__EXECMOD and CHR_FILE__EXECMOD the same. This patch drops
those needless perms as well.
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen D. Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
kernel can dynamically remap perms. Drop the open lookup table and put open
in the common file perms.
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen D. Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
Currently there are a number of applications (nautilus being the main one) which
calls access() on files in order to determine how they should be displayed. It
is normal and expected that nautilus will want to see if files are executable
or if they are really read/write-able. access() should return the real
permission. SELinux policy checks are done in access() and can result in lots
of AVC denials as policy denies RWX on files which DAC allows. Currently
SELinux must dontaudit actual attempts to read/write/execute a file in
order to silence these messages (and not flood the logs.) But dontaudit rules
like that can hide real attacks. This patch addes a new common file
permission audit_access. This permission is special in that it is meaningless
and should never show up in an allow rule. Instead the only place this
permission has meaning is in a dontaudit rule like so:
dontaudit nautilus_t sbin_t:file audit_access
With such a rule if nautilus just checks access() we will still get denied and
thus userspace will still get the correct answer but we will not log the denial.
If nautilus attempted to actually perform one of the forbidden actions
(rather than just querying access(2) about it) we would still log a denial.
This type of dontaudit rule should be used sparingly, as it could be a
method for an attacker to probe the system permissions without detection.
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen D. Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
Modify SELinux to dynamically discover class and permission values
upon policy load, based on the dynamic object class/perm discovery
logic from libselinux. A mapping is created between kernel-private
class and permission indices used outside the security server and the
policy values used within the security server.
The mappings are only applied upon kernel-internal computations;
similar mappings for the private indices of userspace object managers
is handled on a per-object manager basis by the userspace AVC. The
interfaces for compute_av and transition_sid are split for kernel
vs. userspace; the userspace functions are distinguished by a _user
suffix.
The kernel-private class indices are no longer tied to the policy
values and thus do not need to skip indices for userspace classes;
thus the kernel class index values are compressed. The flask.h
definitions were regenerated by deleting the userspace classes from
refpolicy's definitions and then regenerating the headers. Going
forward, we can just maintain the flask.h, av_permissions.h, and
classmap.h definitions separately from policy as they are no longer
tied to the policy values. The next patch introduces a utility to
automate generation of flask.h and av_permissions.h from the
classmap.h definitions.
The older kernel class and permission string tables are removed and
replaced by a single security class mapping table that is walked at
policy load to generate the mapping. The old kernel class validation
logic is completely replaced by the mapping logic.
The handle unknown logic is reworked. reject_unknown=1 is handled
when the mappings are computed at policy load time, similar to the old
handling by the class validation logic. allow_unknown=1 is handled
when computing and mapping decisions - if the permission was not able
to be mapped (i.e. undefined, mapped to zero), then it is
automatically added to the allowed vector. If the class was not able
to be mapped (i.e. undefined, mapped to zero), then all permissions
are allowed for it if allow_unknown=1.
avc_audit leverages the new security class mapping table to lookup the
class and permission names from the kernel-private indices.
The mdp program is updated to use the new table when generating the
class definitions and allow rules for a minimal boot policy for the
kernel. It should be noted that this policy will not include any
userspace classes, nor will its policy index values for the kernel
classes correspond with the ones in refpolicy (they will instead match
the kernel-private indices).
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
