[ Upstream commit 674e2b24791cbe8fd5dc8a0aed4cb4404fcd2028 ]

This command:
    # echo foo/bar >/proc/$$/attr/smack/current

gives the task a label 'foo' w/o indication
that label does not match input.
Setting the label with lsm_set_self_attr() syscall
behaves identically.

This occures because:

1) smk_parse_smack() is used to convert input to a label
2) smk_parse_smack() takes only that part from the
   beginning of the input that looks like a label.
3) `/' is prohibited in labels, so only "foo" is taken.

(2) is by design, because smk_parse_smack() is used
for parsing strings which are more than just a label.

Silent failure is not a good thing, and there are two
indicators that this was not done intentionally:

    (size >= SMK_LONGLABEL) ~> invalid

clause at the beginning of the do_setattr() and the
"Returns the length of the smack label" claim
in the do_setattr() description.

So I fixed this by adding one tiny check:
the taken label length == input length.

Since input length is now strictly controlled,
I changed the two ways of setting label

   smack_setselfattr(): lsm_set_self_attr() syscall
   smack_setprocattr(): > /proc/.../current

to accommodate the divergence in
what they understand by "input length":

  smack_setselfattr counts mandatory \0 into input length,
  smack_setprocattr does not.

  smack_setprocattr allows various trailers after label

Related changes:

* fixed description for smk_parse_smack

* allow unprivileged tasks validate label syntax.

* extract smk_parse_label_len() from smk_parse_smack()
  so parsing may be done w/o string allocation.

* extract smk_import_valid_label() from smk_import_entry()
  to avoid repeated parsing.

* smk_parse_smack(): scan null-terminated strings
  for no more than SMK_LONGLABEL(256) characters

* smack_setselfattr(): require struct lsm_ctx . flags == 0
  to reserve them for future.

Fixes: e114e473771c ("Smack: Simplified Mandatory Access Control Kernel")
Signed-off-by: Konstantin Andreev <andreev@swemel.ru>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit 78fc6a94be252b27bb73e4926eed70b5e302a8e0 ]

According to [1], the label of a UNIX domain socket (UDS)
file (i.e., the filesystem object representing the socket)
is not supposed to participate in Smack security.

To achieve this, [1] labels UDS files with "*"
in smack_d_instantiate().

Before [2], smack_d_instantiate() was responsible
for initializing Smack security for all inodes,
except ones under /proc

[2] imposed the sole responsibility for initializing
inode security for newly created filesystem objects
on smack_inode_init_security().

However, smack_inode_init_security() lacks some logic
present in smack_d_instantiate().
In particular, it does not label UDS files with "*".

This patch adds the missing labeling of UDS files
with "*" to smack_inode_init_security().

Labeling UDS files with "*" in smack_d_instantiate()
still works for stale UDS files that already exist on
disk. Stale UDS files are useless, but I keep labeling
them for consistency and maybe to make easier for user
to delete them.

Compared to [1], this version introduces the following
improvements:

  * UDS file label is held inside inode only
    and not saved to xattrs.

  * relabeling UDS files (setxattr, removexattr, etc.)
    is blocked.

[1] 2010-11-24 Casey Schaufler
commit b4e0d5f0791b ("Smack: UDS revision")

[2] 2023-11-16 roberto.sassu
Fixes: e63d86b8b764 ("smack: Initialize the in-memory inode in smack_inode_init_security()")
Link: https://lore.kernel.org/linux-security-module/20231116090125.187209-5-roberto.sassu@huaweicloud.com/

Signed-off-by: Konstantin Andreev <andreev@swemel.ru>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

The current policy management makes it impossible to use IPE
in a general purpose distribution. In such cases the users are not
building the kernel, the distribution is, and access to the private
key included in the trusted keyring is, for obvious reason, not
available.
This means that users have no way to enable IPE, since there will
be no built-in generic policy, and no access to the key to sign
updates validated by the trusted keyring.

Just as we do for dm-verity, kernel modules and more, allow the
secondary and platform keyrings to also validate policies. This
allows users enrolling their own keys in UEFI db or MOK to also
sign policies, and enroll them. This makes it sensible to enable
IPE in general purpose distributions, as it becomes usable by
any user wishing to do so. Keys in these keyrings can already
load kernels and kernel modules, so there is no security
downgrade.

Add a kconfig each, like dm-verity does, but default to enabled if
the dependencies are available.

Signed-off-by: Luca Boccassi <bluca@debian.org>
Reviewed-by: Serge Hallyn <serge@hallyn.com>
[FW: fixed some style issues]
Signed-off-by: Fan Wu <wufan@kernel.org>

Currently IPE accepts an update that has the same version as the policy
being updated, but it doesn't make it a no-op nor it checks that the
old and new policyes are the same. So it is possible to change the
content of a policy, without changing its version. This is very
confusing from userspace when managing policies.
Instead change the update logic to reject updates that have the same
version with ESTALE, as that is much clearer and intuitive behaviour.

Signed-off-by: Luca Boccassi <bluca@debian.org>
Reviewed-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Fan Wu <wufan@kernel.org>

Add IPE's admin and developer documentation to the kernel tree.

Co-developed-by: Fan Wu <wufan@linux.microsoft.com>
Signed-off-by: Deven Bowers <deven.desai@linux.microsoft.com>
Signed-off-by: Fan Wu <wufan@linux.microsoft.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

TOMOYO project has moved to SourceForge.net .

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>

Loadpin cmdline interface "enabled" has been renamed to "enforce"
for a long time, but the User Description Document was not updated.
(Meaning unchanged)

And kernel_read_file* were moved from linux/fs.h to its own
linux/kernel_read_file.h include file. So update that change here.

Signed-off-by: Jiele zhao <unclexiaole@gmail.com>
Link: https://lore.kernel.org/r/20210308020358.102836-1-unclexiaole@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

As reported by Sphinx 2.4.4:

	docs/Documentation/admin-guide/LSM/SafeSetID.rst:110: WARNING: Title underline too short.

	Note on GID policies and setgroups()
	==================

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/4afa281c170daabd1ce522653d5d5d5078ebd92c.1603791716.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

The SafeSetID LSM has functionality for restricting setuid() calls based
on its configured security policies. This patch adds the analogous
functionality for setgid() calls. This is mostly a copy-and-paste change
with some code deduplication, plus slight modifications/name changes to
the policy-rule-related structs (now contain GID rules in addition to
the UID ones) and some type generalization since SafeSetID now needs to
deal with kgid_t and kuid_t types.

Signed-off-by: Thomas Cedeno <thomascedeno@google.com>
Signed-off-by: Micah Morton <mortonm@chromium.org>

Replace one dead link for the same person's original presentation on the
topic and swap an HTTP URL with HTTPS. While here, linkify the text to
make it more readable when rendered.

Link: https://lore.kernel.org/lkml/20200708073346.13177-1-grandmaster@al2klimov.de/
Co-developed-by: Alexander A. Klimov <grandmaster@al2klimov.de>
Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/202007091141.C008B89EC@keescook
Signed-off-by: Jonathan Corbet <corbet@lwn.net>