bpf: lsm: Remove hook to bpf_task_storage_free

free_task() already calls bpf_task_storage_free(). It is not necessary
to call it again on security_task_free(). Remove the hook.

Signed-off-by: Song

bpf: lsm: Remove hook to bpf_task_storage_free

free_task() already calls bpf_task_storage_free(). It is not necessary
to call it again on security_task_free(). Remove the hook.

Signed-off-by: Song Liu <[email protected]>
Signed-off-by: Martin KaFai Lau <[email protected]>
Acked-by: Matt Bobrowski <[email protected]>
Link: https://patch.msgid.link/[email protected]

show more ...

bpf: lsm: Set bpf_lsm_blob_sizes.lbs_task to 0

bpf task local storage is now using task_struct->bpf_storage, so
bpf_lsm_blob_sizes.lbs_task is no longer needed. Remove it to save some
memory.

Fixes

bpf: lsm: Set bpf_lsm_blob_sizes.lbs_task to 0

bpf task local storage is now using task_struct->bpf_storage, so
bpf_lsm_blob_sizes.lbs_task is no longer needed. Remove it to save some
memory.

Fixes: a10787e6d58c ("bpf: Enable task local storage for tracing programs")
Cc: [email protected]
Cc: KP Singh <[email protected]>
Cc: Matt Bobrowski <[email protected]>
Signed-off-by: Song Liu <[email protected]>
Acked-by: Matt Bobrowski <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>

show more ...

lsm: mark the lsm_id variables are marked as static

As the kernel test robot helpfully reminded us, all of the lsm_id
instances defined inside the various LSMs should be marked as static.
The one ex

lsm: mark the lsm_id variables are marked as static

As the kernel test robot helpfully reminded us, all of the lsm_id
instances defined inside the various LSMs should be marked as static.
The one exception is Landlock which uses its lsm_id variable across
multiple source files with an extern declaration in a header file.

Reported-by: kernel test robot <[email protected]>
Suggested-by: Casey Schaufler <[email protected]>
Reviewed-by: Casey Schaufler <[email protected]>
Signed-off-by: Paul Moore <[email protected]>

show more ...

LSM: Identify modules by more than name

Create a struct lsm_id to contain identifying information about Linux
Security Modules (LSMs). At inception this contains the name of the
module and an identi

LSM: Identify modules by more than name

Create a struct lsm_id to contain identifying information about Linux
Security Modules (LSMs). At inception this contains the name of the
module and an identifier associated with the security module. Change
the security_add_hooks() interface to use this structure. Change the
individual modules to maintain their own struct lsm_id and pass it to
security_add_hooks().

The values are for LSM identifiers are defined in a new UAPI
header file linux/lsm.h. Each existing LSM has been updated to
include it's LSMID in the lsm_id.

The LSM ID values are sequential, with the oldest module
LSM_ID_CAPABILITY being the lowest value and the existing modules
numbered in the order they were included in the main line kernel.
This is an arbitrary convention for assigning the values, but
none better presents itself. The value 0 is defined as being invalid.
The values 1-99 are reserved for any special case uses which may
arise in the future. This may include attributes of the LSM
infrastructure itself, possibly related to namespacing or network
attribute management. A special range is identified for such attributes
to help reduce confusion for developers unfamiliar with LSMs.

LSM attribute values are defined for the attributes presented by
modules that are available today. As with the LSM IDs, The value 0
is defined as being invalid. The values 1-99 are reserved for any
special case uses which may arise in the future.

Cc: linux-security-module <[email protected]>
Signed-off-by: Casey Schaufler <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Reviewed-by: Serge Hallyn <[email protected]>
Reviewed-by: Mickael Salaun <[email protected]>
Reviewed-by: John Johansen <[email protected]>
Signed-off-by: Kees Cook <[email protected]>
Nacked-by: Tetsuo Handa <[email protected]>
[PM: forward ported beyond v6.6 due merge window changes]
Signed-off-by: Paul Moore <[email protected]>

show more ...

selinux: remove the runtime disable functionality

After working with the larger SELinux-based distros for several
years, we're finally at a place where we can disable the SELinux
runtime disable fun

selinux: remove the runtime disable functionality

After working with the larger SELinux-based distros for several
years, we're finally at a place where we can disable the SELinux
runtime disable functionality. The existing kernel deprecation
notice explains the functionality and why we want to remove it:

The selinuxfs "disable" node allows SELinux to be disabled at
runtime prior to a policy being loaded into the kernel. If
disabled via this mechanism, SELinux will remain disabled until
the system is rebooted.

The preferred method of disabling SELinux is via the "selinux=0"
boot parameter, but the selinuxfs "disable" node was created to
make it easier for systems with primitive bootloaders that did not
allow for easy modification of the kernel command line.
Unfortunately, allowing for SELinux to be disabled at runtime makes
it difficult to secure the kernel's LSM hooks using the
"__ro_after_init" feature.

It is that last sentence, mentioning the '__ro_after_init' hardening,
which is the real motivation for this change, and if you look at the
diffstat you'll see that the impact of this patch reaches across all
the different LSMs, helping prevent tampering at the LSM hook level.

From a SELinux perspective, it is important to note that if you
continue to disable SELinux via "/etc/selinux/config" it may appear
that SELinux is disabled, but it is simply in an uninitialized state.
If you load a policy with `load_policy -i`, you will see SELinux
come alive just as if you had loaded the policy during early-boot.

It is also worth noting that the "/sys/fs/selinux/disable" file is
always writable now, regardless of the Kconfig settings, but writing
to the file has no effect on the system, other than to display an
error on the console if a non-zero/true value is written.

Finally, in the several years where we have been working on
deprecating this functionality, there has only been one instance of
someone mentioning any user visible breakage. In this particular
case it was an individual's kernel test system, and the workaround
documented in the deprecation notice ("selinux=0" on the kernel
command line) resolved the issue without problem.

Acked-by: Casey Schaufler <[email protected]>
Signed-off-by: Paul Moore <[email protected]>

show more ...

bpf: Implement task local storage

Similar to bpf_local_storage for sockets and inodes add local storage
for task_struct.

The life-cycle of storage is managed with the life-cycle of the
task_struct.

bpf: Implement task local storage

Similar to bpf_local_storage for sockets and inodes add local storage
for task_struct.

The life-cycle of storage is managed with the life-cycle of the
task_struct. i.e. the storage is destroyed along with the owning task
with a callback to the bpf_task_storage_free from the task_free LSM
hook.

The BPF LSM allocates an __rcu pointer to the bpf_local_storage in
the security blob which are now stackable and can co-exist with other
LSMs.

The userspace map operations can be done by using a pid fd as a key
passed to the lookup, update and delete operations.

Signed-off-by: KP Singh <[email protected]>
Signed-off-by: Alexei Starovoitov <[email protected]>
Acked-by: Song Liu <[email protected]>
Acked-by: Martin KaFai Lau <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]

show more ...

bpf: Implement bpf_local_storage for inodes

Similar to bpf_local_storage for sockets, add local storage for inodes.
The life-cycle of storage is managed with the life-cycle of the inode.
i.e. the st

bpf: Implement bpf_local_storage for inodes

Similar to bpf_local_storage for sockets, add local storage for inodes.
The life-cycle of storage is managed with the life-cycle of the inode.
i.e. the storage is destroyed along with the owning inode.

The BPF LSM allocates an __rcu pointer to the bpf_local_storage in the
security blob which are now stackable and can co-exist with other LSMs.

Signed-off-by: KP Singh <[email protected]>
Signed-off-by: Alexei Starovoitov <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]

show more ...

bpf: lsm: Initialize the BPF LSM hooks

* The hooks are initialized using the definitions in
include/linux/lsm_hook_defs.h.
* The LSM can be enabled / disabled with CONFIG_BPF_LSM.

Signed-off-by:

bpf: lsm: Initialize the BPF LSM hooks

* The hooks are initialized using the definitions in
include/linux/lsm_hook_defs.h.
* The LSM can be enabled / disabled with CONFIG_BPF_LSM.

Signed-off-by: KP Singh <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Reviewed-by: Brendan Jackman <[email protected]>
Reviewed-by: Florent Revest <[email protected]>
Acked-by: Kees Cook <[email protected]>
Acked-by: James Morris <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]

show more ...