14 Apr, 2020

1 commit

  • Original cgroup v2 eBPF code for filtering device access made it
    possible to compile with CONFIG_CGROUP_DEVICE=n and still use the eBPF
    filtering. Change
    commit 4b7d4d453fc4 ("device_cgroup: Export devcgroup_check_permission")
    reverted this, making it required to set it to y.

    Since the device filtering (and all the docs) for cgroup v2 is no longer
    a "device controller" like it was in v1, someone might compile their
    kernel with CONFIG_CGROUP_DEVICE=n. Then (for linux 5.5+) the eBPF
    filter will not be invoked, and all processes will be allowed access
    to all devices, no matter what the eBPF filter says.

    Signed-off-by: Odin Ugedal
    Acked-by: Roman Gushchin
    Signed-off-by: Tejun Heo

    Odin Ugedal
     

30 Mar, 2020

1 commit

  • * 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
    Signed-off-by: Daniel Borkmann
    Reviewed-by: Brendan Jackman
    Reviewed-by: Florent Revest
    Acked-by: Kees Cook
    Acked-by: James Morris
    Link: https://lore.kernel.org/bpf/20200329004356.27286-6-kpsingh@chromium.org

    KP Singh
     

11 Dec, 2019

1 commit

  • The lsm_audit code is only required when CONFIG_SECURITY is enabled.
    It does not have a build dependency on CONFIG_AUDIT since audit.h
    provides trivial static inlines for audit_log*() when CONFIG_AUDIT
    is disabled. Hence, the Makefile should only add lsm_audit to the
    obj lists based on CONFIG_SECURITY, not CONFIG_AUDIT.

    Fixes: 59438b46471a ("security,lockdown,selinux: implement SELinux lockdown")
    Signed-off-by: Stephen Smalley
    Signed-off-by: Paul Moore

    Stephen Smalley
     

20 Aug, 2019

1 commit

  • While existing LSMs can be extended to handle lockdown policy,
    distributions generally want to be able to apply a straightforward
    static policy. This patch adds a simple LSM that can be configured to
    reject either integrity or all lockdown queries, and can be configured
    at runtime (through securityfs), boot time (via a kernel parameter) or
    build time (via a kconfig option). Based on initial code by David
    Howells.

    Signed-off-by: Matthew Garrett
    Reviewed-by: Kees Cook
    Cc: David Howells
    Signed-off-by: James Morris

    Matthew Garrett
     

26 Jan, 2019

1 commit

  • SafeSetID gates the setid family of syscalls to restrict UID/GID
    transitions from a given UID/GID to only those approved by a
    system-wide whitelist. These restrictions also prohibit the given
    UIDs/GIDs from obtaining auxiliary privileges associated with
    CAP_SET{U/G}ID, such as allowing a user to set up user namespace UID
    mappings. For now, only gating the set*uid family of syscalls is
    supported, with support for set*gid coming in a future patch set.

    Signed-off-by: Micah Morton
    Acked-by: Kees Cook
    Signed-off-by: James Morris

    Micah Morton
     

02 Nov, 2017

1 commit

  • Many source files in the tree are missing licensing information, which
    makes it harder for compliance tools to determine the correct license.

    By default all files without license information are under the default
    license of the kernel, which is GPL version 2.

    Update the files which contain no license information with the 'GPL-2.0'
    SPDX license identifier. The SPDX identifier is a legally binding
    shorthand, which can be used instead of the full boiler plate text.

    This patch is based on work done by Thomas Gleixner and Kate Stewart and
    Philippe Ombredanne.

    How this work was done:

    Patches were generated and checked against linux-4.14-rc6 for a subset of
    the use cases:
    - file had no licensing information it it.
    - file was a */uapi/* one with no licensing information in it,
    - file was a */uapi/* one with existing licensing information,

    Further patches will be generated in subsequent months to fix up cases
    where non-standard license headers were used, and references to license
    had to be inferred by heuristics based on keywords.

    The analysis to determine which SPDX License Identifier to be applied to
    a file was done in a spreadsheet of side by side results from of the
    output of two independent scanners (ScanCode & Windriver) producing SPDX
    tag:value files created by Philippe Ombredanne. Philippe prepared the
    base worksheet, and did an initial spot review of a few 1000 files.

    The 4.13 kernel was the starting point of the analysis with 60,537 files
    assessed. Kate Stewart did a file by file comparison of the scanner
    results in the spreadsheet to determine which SPDX license identifier(s)
    to be applied to the file. She confirmed any determination that was not
    immediately clear with lawyers working with the Linux Foundation.

    Criteria used to select files for SPDX license identifier tagging was:
    - Files considered eligible had to be source code files.
    - Make and config files were included as candidates if they contained >5
    lines of source
    - File already had some variant of a license header in it (even if
    Reviewed-by: Philippe Ombredanne
    Reviewed-by: Thomas Gleixner
    Signed-off-by: Greg Kroah-Hartman

    Greg Kroah-Hartman
     

21 Apr, 2016

1 commit

  • This LSM enforces that kernel-loaded files (modules, firmware, etc)
    must all come from the same filesystem, with the expectation that
    such a filesystem is backed by a read-only device such as dm-verity
    or CDROM. This allows systems that have a verified and/or unchangeable
    filesystem to enforce module and firmware loading restrictions without
    needing to sign the files individually.

    Signed-off-by: Kees Cook
    Acked-by: Serge Hallyn
    Signed-off-by: James Morris

    Kees Cook
     

12 May, 2015

1 commit

  • Instead of using a vector of security operations
    with explicit, special case stacking of the capability
    and yama hooks use lists of hooks with capability and
    yama hooks included as appropriate.

    The security_operations structure is no longer required.
    Instead, there is a union of the function pointers that
    allows all the hooks lists to use a common mechanism for
    list management while retaining typing. Each module
    supplies an array describing the hooks it provides instead
    of a sparsely populated security_operations structure.
    The description includes the element that gets put on
    the hook list, avoiding the issues surrounding individual
    element allocation.

    The method for registering security modules is changed to
    reflect the information available. The method for removing
    a module, currently only used by SELinux, has also changed.
    It should be generic now, however if there are potential
    race conditions based on ordering of hook removal that needs
    to be addressed by the calling module.

    The security hooks are called from the lists and the first
    failure is returned.

    Signed-off-by: Casey Schaufler
    Acked-by: John Johansen
    Acked-by: Kees Cook
    Acked-by: Paul Moore
    Acked-by: Stephen Smalley
    Acked-by: Tetsuo Handa
    Signed-off-by: James Morris

    Casey Schaufler
     

17 Feb, 2014

1 commit


24 Sep, 2013

1 commit

  • Back when we had half ass LSM stacking we had to link capabilities.o
    after bigger LSMs so that on initialization the bigger LSM would
    register first and the capabilities module would be the one stacked as
    the 'seconday'. Somewhere around 6f0f0fd496333777d53 (back in 2008) we
    finally removed the last of the kinda module stacking code but this
    comment in the makefile still lives today.

    Reported-by: Valdis Kletnieks
    Signed-off-by: Eric Paris
    Signed-off-by: James Morris

    Eric Paris
     

10 Feb, 2012

1 commit

  • This adds the Yama Linux Security Module to collect DAC security
    improvements (specifically just ptrace restrictions for now) that have
    existed in various forms over the years and have been carried outside the
    mainline kernel by other Linux distributions like Openwall and grsecurity.

    Signed-off-by: Kees Cook
    Acked-by: John Johansen
    Signed-off-by: James Morris

    Kees Cook
     

19 Jul, 2011

1 commit

  • Move the inode integrity data(iint) management up to the integrity directory
    in order to share the iint among the different integrity models.

    Changelog:
    - don't define MAX_DIGEST_SIZE
    - rename several globally visible 'ima_' prefixed functions, structs,
    locks, etc to 'integrity_'
    - replace '20' with SHA1_DIGEST_SIZE
    - reflect location change in appropriate Kconfig and Makefiles
    - remove unnecessary initialization of iint_initialized to 0
    - rebased on current ima_iint.c
    - define integrity_iint_store/lock as static

    There should be no other functional changes.

    Signed-off-by: Mimi Zohar
    Acked-by: Serge Hallyn

    Mimi Zohar
     

02 Aug, 2010

1 commit


17 Dec, 2009

1 commit

  • In NOMMU mode clamp dac_mmap_min_addr to zero to cause the tests on it to be
    skipped by the compiler. We do this as the minimum mmap address doesn't make
    any sense in NOMMU mode.

    mmap_min_addr and round_hint_to_min() can be discarded entirely in NOMMU mode.

    Signed-off-by: David Howells
    Acked-by: Eric Paris
    Signed-off-by: James Morris

    David Howells
     

20 Oct, 2009

1 commit

  • Remove the root_plug example LSM code. It's unmaintained and
    increasingly broken in various ways.

    Made at the 2009 Kernel Summit in Tokyo!

    Acked-by: Greg Kroah-Hartman
    Signed-off-by: James Morris

    James Morris
     

17 Aug, 2009

1 commit

  • Convert avc_audit in security/selinux/avc.c to use lsm_audit.h,
    for better maintainability.

    - changed selinux to use common_audit_data instead of
    avc_audit_data
    - eliminated code in avc.c and used code from lsm_audit.h instead.

    Had to add a LSM_AUDIT_NO_AUDIT to lsm_audit.h so that avc_audit
    can call common_lsm_audit and do the pre and post callbacks without
    doing the actual dump. This makes it so that the patched version
    behaves the same way as the unpatched version.

    Also added a denied field to the selinux_audit_data private space,
    once again to make it so that the patched version behaves like the
    unpatched.

    I've tested and confirmed that AVCs look the same before and after
    this patch.

    Signed-off-by: Thomas Liu
    Acked-by: Stephen Smalley
    Signed-off-by: James Morris

    Thomas Liu
     

06 Aug, 2009

1 commit

  • Currently SELinux enforcement of controls on the ability to map low memory
    is determined by the mmap_min_addr tunable. This patch causes SELinux to
    ignore the tunable and instead use a seperate Kconfig option specific to how
    much space the LSM should protect.

    The tunable will now only control the need for CAP_SYS_RAWIO and SELinux
    permissions will always protect the amount of low memory designated by
    CONFIG_LSM_MMAP_MIN_ADDR.

    This allows users who need to disable the mmap_min_addr controls (usual reason
    being they run WINE as a non-root user) to do so and still have SELinux
    controls preventing confined domains (like a web server) from being able to
    map some area of low memory.

    Signed-off-by: Eric Paris
    Signed-off-by: James Morris

    Eric Paris
     

13 Jul, 2009

2 commits

  • This reverts commit 8113a8d80f4c6a3dc3724b39b470f3fee9c426b6.

    The patch causes a stack overflow on my system during boot.

    Signed-off-by: James Morris

    James Morris
     
  • Convert avc_audit in security/selinux/avc.c to use lsm_audit.h,
    for better maintainability and for less code duplication.

    - changed selinux to use common_audit_data instead of
    avc_audit_data
    - eliminated code in avc.c and used code from lsm_audit.h instead.

    I have tested to make sure that the avcs look the same before and
    after this patch.

    Signed-off-by: Thomas Liu
    Acked-by: Eric Paris
    Signed-off-by: James Morris

    Thomas Liu
     

14 Apr, 2009

1 commit

  • the following patch, add logging of Smack security decisions.
    This is of course very useful to understand what your current smack policy does.
    As suggested by Casey, it also now forbids labels with ', " or \

    It introduces a '/smack/logging' switch :
    0: no logging
    1: log denied (default)
    2: log accepted
    3: log denied&accepted

    Signed-off-by: Etienne Basset
    Acked-by: Casey Schaufler
    Acked-by: Eric Paris
    Signed-off-by: James Morris

    Etienne Basset
     

12 Feb, 2009

2 commits


06 Feb, 2009

1 commit

  • IMA provides hardware (TPM) based measurement and attestation for
    file measurements. As the Trusted Computing (TPM) model requires,
    IMA measures all files before they are accessed in any way (on the
    integrity_bprm_check, integrity_path_check and integrity_file_mmap
    hooks), and commits the measurements to the TPM. Once added to the
    TPM, measurements can not be removed.

    In addition, IMA maintains a list of these file measurements, which
    can be used to validate the aggregate value stored in the TPM. The
    TPM can sign these measurements, and thus the system can prove, to
    itself and to a third party, the system's integrity in a way that
    cannot be circumvented by malicious or compromised software.

    - alloc ima_template_entry before calling ima_store_template()
    - log ima_add_boot_aggregate() failure
    - removed unused IMA_TEMPLATE_NAME_LEN
    - replaced hard coded string length with #define name

    Signed-off-by: Mimi Zohar
    Signed-off-by: James Morris

    Mimi Zohar
     

28 Aug, 2008

1 commit

  • Add a new Kconfig option SECURITYFS which will build securityfs support
    but does not require CONFIG_SECURITY. The only current user of
    securityfs does not depend on CONFIG_SECURITY and there is no reason the
    full LSM needs to be built to build this fs.

    Signed-off-by: Eric Paris
    Signed-off-by: James Morris

    Eric Paris
     

14 Jul, 2008

1 commit


29 Apr, 2008

1 commit

  • Implement a cgroup to track and enforce open and mknod restrictions on device
    files. A device cgroup associates a device access whitelist with each cgroup.
    A whitelist entry has 4 fields. 'type' is a (all), c (char), or b (block).
    'all' means it applies to all types and all major and minor numbers. Major
    and minor are either an integer or * for all. Access is a composition of r
    (read), w (write), and m (mknod).

    The root device cgroup starts with rwm to 'all'. A child devcg gets a copy of
    the parent. Admins can then remove devices from the whitelist or add new
    entries. A child cgroup can never receive a device access which is denied its
    parent. However when a device access is removed from a parent it will not
    also be removed from the child(ren).

    An entry is added using devices.allow, and removed using
    devices.deny. For instance

    echo 'c 1:3 mr' > /cgroups/1/devices.allow

    allows cgroup 1 to read and mknod the device usually known as
    /dev/null. Doing

    echo a > /cgroups/1/devices.deny

    will remove the default 'a *:* mrw' entry.

    CAP_SYS_ADMIN is needed to change permissions or move another task to a new
    cgroup. A cgroup may not be granted more permissions than the cgroup's parent
    has. Any task can move itself between cgroups. This won't be sufficient, but
    we can decide the best way to adequately restrict movement later.

    [akpm@linux-foundation.org: coding-style fixes]
    [akpm@linux-foundation.org: fix may-be-used-uninitialized warning]
    Signed-off-by: Serge E. Hallyn
    Acked-by: James Morris
    Looks-good-to: Pavel Emelyanov
    Cc: Daniel Hokka Zakrisson
    Cc: Li Zefan
    Cc: Paul Menage
    Cc: Balbir Singh
    Cc: KAMEZAWA Hiroyuki
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Serge E. Hallyn
     

06 Feb, 2008

1 commit

  • Smack is the Simplified Mandatory Access Control Kernel.

    Smack implements mandatory access control (MAC) using labels
    attached to tasks and data containers, including files, SVIPC,
    and other tasks. Smack is a kernel based scheme that requires
    an absolute minimum of application support and a very small
    amount of configuration data.

    Smack uses extended attributes and
    provides a set of general mount options, borrowing technics used
    elsewhere. Smack uses netlabel for CIPSO labeling. Smack provides
    a pseudo-filesystem smackfs that is used for manipulation of
    system Smack attributes.

    The patch, patches for ls and sshd, a README, a startup script,
    and x86 binaries for ls and sshd are also available on

    http://www.schaufler-ca.com

    Development has been done using Fedora Core 7 in a virtual machine
    environment and on an old Sony laptop.

    Smack provides mandatory access controls based on the label attached
    to a task and the label attached to the object it is attempting to
    access. Smack labels are deliberately short (1-23 characters) text
    strings. Single character labels using special characters are reserved
    for system use. The only operation applied to Smack labels is equality
    comparison. No wildcards or expressions, regular or otherwise, are
    used. Smack labels are composed of printable characters and may not
    include "/".

    A file always gets the Smack label of the task that created it.

    Smack defines and uses these labels:

    "*" - pronounced "star"
    "_" - pronounced "floor"
    "^" - pronounced "hat"
    "?" - pronounced "huh"

    The access rules enforced by Smack are, in order:

    1. Any access requested by a task labeled "*" is denied.
    2. A read or execute access requested by a task labeled "^"
    is permitted.
    3. A read or execute access requested on an object labeled "_"
    is permitted.
    4. Any access requested on an object labeled "*" is permitted.
    5. Any access requested by a task on an object with the same
    label is permitted.
    6. Any access requested that is explicitly defined in the loaded
    rule set is permitted.
    7. Any other access is denied.

    Rules may be explicitly defined by writing subject,object,access
    triples to /smack/load.

    Smack rule sets can be easily defined that describe Bell&LaPadula
    sensitivity, Biba integrity, and a variety of interesting
    configurations. Smack rule sets can be modified on the fly to
    accommodate changes in the operating environment or even the time
    of day.

    Some practical use cases:

    Hierarchical levels. The less common of the two usual uses
    for MLS systems is to define hierarchical levels, often
    unclassified, confidential, secret, and so on. To set up smack
    to support this, these rules could be defined:

    C Unclass rx
    S C rx
    S Unclass rx
    TS S rx
    TS C rx
    TS Unclass rx

    A TS process can read S, C, and Unclass data, but cannot write it.
    An S process can read C and Unclass. Note that specifying that
    TS can read S and S can read C does not imply TS can read C, it
    has to be explicitly stated.

    Non-hierarchical categories. This is the more common of the
    usual uses for an MLS system. Since the default rule is that a
    subject cannot access an object with a different label no
    access rules are required to implement compartmentalization.

    A case that the Bell & LaPadula policy does not allow is demonstrated
    with this Smack access rule:

    A case that Bell&LaPadula does not allow that Smack does:

    ESPN ABC r
    ABC ESPN r

    On my portable video device I have two applications, one that
    shows ABC programming and the other ESPN programming. ESPN wants
    to show me sport stories that show up as news, and ABC will
    only provide minimal information about a sports story if ESPN
    is covering it. Each side can look at the other's info, neither
    can change the other. Neither can see what FOX is up to, which
    is just as well all things considered.

    Another case that I especially like:

    SatData Guard w
    Guard Publish w

    A program running with the Guard label opens a UDP socket and
    accepts messages sent by a program running with a SatData label.
    The Guard program inspects the message to ensure it is wholesome
    and if it is sends it to a program running with the Publish label.
    This program then puts the information passed in an appropriate
    place. Note that the Guard program cannot write to a Publish
    file system object because file system semanitic require read as
    well as write.

    The four cases (categories, levels, mutual read, guardbox) here
    are all quite real, and problems I've been asked to solve over
    the years. The first two are easy to do with traditonal MLS systems
    while the last two you can't without invoking privilege, at least
    for a while.

    Signed-off-by: Casey Schaufler
    Cc: Joshua Brindle
    Cc: Paul Moore
    Cc: Stephen Smalley
    Cc: Chris Wright
    Cc: James Morris
    Cc: "Ahmed S. Darwish"
    Cc: Andrew G. Morgan
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Casey Schaufler
     

30 Sep, 2006

1 commit

  • This code has suffered from broken core design and lack of developer
    attention. Broken security modules are too dangerous to leave around. It
    is time to remove this one.

    Signed-off-by: Chris Wright
    Acked-by: Michael Halcrow
    Acked-by: Serge Hallyn
    Cc: Davi Arnaut
    Acked-by: Greg Kroah-Hartman
    Acked-by: James Morris
    Acked-by: Alan Cox
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Chris Wright
     

09 Jul, 2005

1 commit

  • Here's a small patch against 2.6.13-rc2 that adds securityfs, a virtual
    fs that all LSMs can use instead of creating their own. The fs should
    be mounted at /sys/kernel/security, and the fs creates that mount point.
    This will make the LSB people happy that we aren't creating a new
    /my_lsm_fs directory in the root for every different LSM.

    It has changed a bit since the last version, thanks to comments from
    Mike Waychison.

    Signed-off-by: Greg Kroah-Hartman
    Signed-off-by: Chris Wright

    Greg KH
     

17 Apr, 2005

1 commit

  • Initial git repository build. I'm not bothering with the full history,
    even though we have it. We can create a separate "historical" git
    archive of that later if we want to, and in the meantime it's about
    3.2GB when imported into git - space that would just make the early
    git days unnecessarily complicated, when we don't have a lot of good
    infrastructure for it.

    Let it rip!

    Linus Torvalds