10 Aug, 2020

1 commit

  • To build host programs, you need to add the program names to 'hostprogs'
    to use the necessary build rule, but it is not enough to build them
    because there is no dependency.

    There are two types of host programs: built as the prerequisite of
    another (e.g. gen_crc32table in lib/Makefile), or always built when
    Kbuild visits the Makefile (e.g. genksyms in scripts/genksyms/Makefile).

    The latter is typical in Makefiles under scripts/, which contains host
    programs globally used during the kernel build. To build them, you need
    to add them to both 'hostprogs' and 'always-y'.

    This commit adds hostprogs-always-y as a shorthand.

    The same applies to user programs. net/bpfilter/Makefile builds
    bpfilter_umh on demand, hence always-y is unneeded. In contrast,
    programs under samples/ are added to both 'userprogs' and 'always-y'
    so they are always built when Kbuild visits the Makefiles.

    userprogs-always-y works as a shorthand.

    Signed-off-by: Masahiro Yamada
    Acked-by: Miguel Ojeda

    Masahiro Yamada
     

04 Apr, 2020

1 commit

  • Pull SPDX updates from Greg KH:
    "Here are three SPDX patches for 5.7-rc1.

    One fixes up the SPDX tag for a single driver, while the other two go
    through the tree and add SPDX tags for all of the .gitignore files as
    needed.

    Nothing too complex, but you will get a merge conflict with your
    current tree, that should be trivial to handle (one file modified by
    two things, one file deleted.)

    All three of these have been in linux-next for a while, with no
    reported issues other than the merge conflict"

    * tag 'spdx-5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/spdx:
    ASoC: MT6660: make spdxcheck.py happy
    .gitignore: add SPDX License Identifier
    .gitignore: remove too obvious comments

    Linus Torvalds
     

25 Mar, 2020

1 commit


28 Feb, 2020

1 commit

  • Remove initial SIDs that have never been used or are no longer used by
    the kernel from its string table, which is also used to generate the
    SECINITSID_* symbols referenced in code. Update the code to
    gracefully handle the fact that these can now be NULL. Stop treating
    it as an error if a policy defines additional initial SIDs unknown to
    the kernel. Do not load unused initial SID contexts into the sidtab.
    Fix the incorrect usage of the name from the ocontext in error
    messages when loading initial SIDs since these are not presently
    written to the kernel policy and are therefore always NULL.

    After this change, it is possible to safely reclaim and reuse some of
    the unused initial SIDs without compatibility issues. Specifically,
    unused initial SIDs that were being assigned the same context as the
    unlabeled initial SID in policies can be reclaimed and reused for
    another purpose, with existing policies still treating them as having
    the unlabeled context and future policies having the option of mapping
    them to a more specific context. For example, this could have been
    used when the infiniband labeling support was introduced to define
    initial SIDs for the default pkey and endport SIDs similar to the
    handling of port/netif/node SIDs rather than always using
    SECINITSID_UNLABELED as the default.

    The set of safely reclaimable unused initial SIDs across all known
    policies is igmp_packet (13), icmp_socket (14), tcp_socket (15), kmod
    (24), policy (25), and scmp_packet (26); these initial SIDs were
    assigned the same context as unlabeled in all known policies including
    mls. If only considering non-mls policies (i.e. assuming that mls
    users always upgrade policy with their kernels), the set of safely
    reclaimable unused initial SIDs further includes file_labels (6), init
    (7), sysctl_modprobe (16), and sysctl_fs (18) through sysctl_dev (23).

    Adding new initial SIDs beyond SECINITSID_NUM to policy unfortunately
    became a fatal error in commit 24ed7fdae669 ("selinux: use separate
    table for initial SID lookup") and even before that it could cause
    problems on a policy reload (collision between the new initial SID and
    one allocated at runtime) ever since commit 42596eafdd75 ("selinux:
    load the initial SIDs upon every policy load") so we cannot safely
    start adding new initial SIDs to policies beyond SECINITSID_NUM (27)
    until such a time as all such kernels do not need to be supported and
    only those that include this commit are relevant. That is not a big
    deal since we haven't added a new initial SID since 2004 (v2.6.7) and
    we have plenty of unused ones we can reclaim if we truly need one.

    If we want to avoid the wasted storage in initial_sid_to_string[]
    and/or sidtab->isids[] for the unused initial SIDs, we could introduce
    an indirection between the kernel initial SID values and the policy
    initial SID values and just map the policy SID values in the ocontexts
    to the kernel values during policy_load_isids(). Originally I thought
    we'd do this by preserving the initial SID names in the kernel policy
    and creating a mapping at load time like we do for the security
    classes and permissions but that would require a new kernel policy
    format version and associated changes to libsepol/checkpolicy and I'm
    not sure it is justified. Simpler approach is just to create a fixed
    mapping table in the kernel from the existing fixed policy values to
    the kernel values. Less flexible but probably sufficient.

    A separate selinux userspace change was applied in
    https://github.com/SELinuxProject/selinux/commit/8677ce5e8f592950ae6f14cea1b68a20ddc1ac25
    to enable removal of most of the unused initial SID contexts from
    policies, but there is no dependency between that change and this one.
    That change permits removing all of the unused initial SID contexts
    from policy except for the fs and sysctl SID contexts. The initial
    SID declarations themselves would remain in policy to preserve the
    values of subsequent ones but the contexts can be dropped. If/when
    the kernel decides to reuse one of them, future policies can change
    the name and start assigning a context again without breaking
    compatibility.

    Here is how I would envision staging changes to the initial SIDs in a
    compatible manner after this commit is applied:

    1. At any time after this commit is applied, the kernel could choose
    to reclaim one of the safely reclaimable unused initial SIDs listed
    above for a new purpose (i.e. replace its NULL entry in the
    initial_sid_to_string[] table with a new name and start using the
    newly generated SECINITSID_name symbol in code), and refpolicy could
    at that time rename its declaration of that initial SID to reflect its
    new purpose and start assigning it a context going
    forward. Existing/old policies would map the reclaimed initial SID to
    the unlabeled context, so that would be the initial default behavior
    until policies are updated. This doesn't depend on the selinux
    userspace change; it will work with existing policies and userspace.

    2. In 6 months or so we'll have another SELinux userspace release that
    will include the libsepol/checkpolicy support for omitting unused
    initial SID contexts.

    3. At any time after that release, refpolicy can make that release its
    minimum build requirement and drop the sid context statements (but not
    the sid declarations) for all of the unused initial SIDs except for
    fs and sysctl, which must remain for compatibility on policy
    reload with old kernels and for compatibility with kernels that were
    still using SECINITSID_SYSCTL (< 2.6.39). This doesn't depend on this
    kernel commit; it will work with previous kernels as well.

    4. After N years for some value of N, refpolicy decides that it no
    longer cares about policy reload compatibility for kernels that
    predate this kernel commit, and refpolicy drops the fs and sysctl
    SID contexts from policy too (but retains the declarations).

    5. After M years for some value of M, the kernel decides that it no
    longer cares about compatibility with refpolicies that predate step 4
    (dropping the fs and sysctl SIDs), and those two SIDs also become
    safely reclaimable. This step is optional and need not ever occur unless
    we decide that the need to reclaim those two SIDs outweighs the
    compatibility cost.

    6. After O years for some value of O, refpolicy decides that it no
    longer cares about policy load (not just reload) compatibility for
    kernels that predate this kernel commit, and both kernel and refpolicy
    can then start adding and using new initial SIDs beyond 27. This does
    not depend on the previous change (step 5) and can occur independent
    of it.

    Fixes: https://github.com/SELinuxProject/selinux-kernel/issues/12
    Signed-off-by: Stephen Smalley
    Signed-off-by: Paul Moore

    Stephen Smalley
     

04 Feb, 2020

1 commit

  • In old days, the "host-progs" syntax was used for specifying host
    programs. It was renamed to the current "hostprogs-y" in 2004.

    It is typically useful in scripts/Makefile because it allows Kbuild to
    selectively compile host programs based on the kernel configuration.

    This commit renames like follows:

    always -> always-y
    hostprogs-y -> hostprogs

    So, scripts/Makefile will look like this:

    always-$(CONFIG_BUILD_BIN2C) += ...
    always-$(CONFIG_KALLSYMS) += ...
    ...
    hostprogs := $(always-y) $(always-m)

    I think this makes more sense because a host program is always a host
    program, irrespective of the kernel configuration. We want to specify
    which ones to compile by CONFIG options, so always-y will be handier.

    The "always", "hostprogs-y", "hostprogs-m" will be kept for backward
    compatibility for a while.

    Signed-off-by: Masahiro Yamada

    Masahiro Yamada
     

29 Apr, 2019

1 commit

  • When compiling genheaders and mdp from a newer host kernel, the
    following error happens:

    In file included from scripts/selinux/genheaders/genheaders.c:18:
    ./security/selinux/include/classmap.h:238:2: error: #error New
    address family defined, please update secclass_map. #error New
    address family defined, please update secclass_map. ^~~~~
    make[3]: *** [scripts/Makefile.host:107:
    scripts/selinux/genheaders/genheaders] Error 1 make[2]: ***
    [scripts/Makefile.build:599: scripts/selinux/genheaders] Error 2
    make[1]: *** [scripts/Makefile.build:599: scripts/selinux] Error 2
    make[1]: *** Waiting for unfinished jobs....

    Instead of relying on the host definition, include linux/socket.h in
    classmap.h to have PF_MAX.

    Cc: stable@vger.kernel.org
    Signed-off-by: Paulo Alcantara
    Acked-by: Stephen Smalley
    [PM: manually merge in mdp.c, subject line tweaks]
    Signed-off-by: Paul Moore

    Paulo Alcantara
     

10 Dec, 2018

1 commit

  • Please, use at least K&R C; printf had been able to left-adjust
    a field for as long as stdio existed and use of '*' for variable
    width had been there since v7. Yes, the first edition of K&R
    didn't cover the latter feature (it slightly predates v7), but
    you are using a much later feature of the language than that -
    in K&R C
    static char *stoupperx(const char *s)
    {
    ...
    }
    would've been spelled as
    static char *stoupperx(s)
    char *s;
    {
    ...
    }

    While we are at it, the use of strstr() is bogus - it finds the
    _first_ instance of substring, so it's a lousy fit for checking
    if a string ends with given suffix...

    Signed-off-by: Al Viro

    Al Viro
     

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
     

01 Aug, 2017

1 commit


11 Mar, 2017

1 commit

  • Compiling with clang and -Wundef makes the compiler report a usage of
    undefined PF_MAX macro in security/selinux/include/classmap.h:

    In file included from scripts/selinux/mdp/mdp.c:48:
    security/selinux/include/classmap.h:37:31: warning: no previous
    extern declaration for non-static variable 'secclass_map'
    [-Wmissing-variable-declarations]
    struct security_class_mapping secclass_map[] = {
    ^
    security/selinux/include/classmap.h:235:5: error: 'PF_MAX' is not
    defined, evaluates to 0 [-Werror,-Wundef]
    #if PF_MAX > 43
    ^
    In file included from scripts/selinux/genheaders/genheaders.c:17:
    security/selinux/include/classmap.h:37:31: warning: no previous
    extern declaration for non-static variable 'secclass_map'
    [-Wmissing-variable-declarations]
    struct security_class_mapping secclass_map[] = {
    ^
    security/selinux/include/classmap.h:235:5: error: 'PF_MAX' is not
    defined, evaluates to 0 [-Werror,-Wundef]
    #if PF_MAX > 43
    ^

    PF_MAX is defined in include/linux/socket.h but not in
    include/uapi/linux/socket.h. Therefore host programs have to rely on the
    definition from libc's /usr/include/bits/socket.h, included by
    .

    Fix the issue by using sys/socket.h in mdp and genheaders. When
    classmap.h is included by security/selinux/avc.c, it uses the kernel
    definition of PF_MAX, which makes the test consistent.

    Signed-off-by: Nicolas Iooss
    Signed-off-by: Paul Moore

    Nicolas Iooss
     

21 Dec, 2016

1 commit

  • Commit 3322d0d64f4e ("selinux: keep SELinux in sync with new capability
    definitions") added a check on the defined capabilities without
    explicitly including the capability header file which caused problems
    when building genheaders for users of clang/llvm. Resolve this by
    using the kernel headers when building genheaders, which is arguably
    the right thing to do regardless, and explicitly including the
    kernel's capability.h header file in classmap.h. We also update the
    mdp build, even though it wasn't causing an error we really should
    be using the headers from the kernel we are building.

    Reported-by: Nicolas Iooss
    Signed-off-by: Paul Moore

    Paul Moore
     

18 Jun, 2014

1 commit


04 Mar, 2011

1 commit

  • 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
    Signed-off-by: Eric Paris
    Acked-by: Stephen Smalley

    Harry Ciao
     

16 Mar, 2010

1 commit

  • Fix const warning in the genheaders script as a result of
    changes to the headers, as noted here:

    http://linux.derkeiler.com/Mailing-Lists/Kernel/2010-03/msg03977.html

    Reported-by: Stephen Rothwell
    Signed-off-by: James Morris

    James Morris
     

23 Nov, 2009

1 commit

  • If a permission name is long enough the selinux class definition generation
    tool will go into a infinite loop. This is because it's macro max() is
    fooled into thinking it is dealing with unsigned numbers. This patch makes
    sure the macro always uses signed number so 1 > -1.

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

    Eric Paris
     

19 Nov, 2009

1 commit

  • scripts/selinux/genheaders/genheaders.c:20: warning: no previous prototype
    for ?usage?
    scripts/selinux/genheaders/genheaders.c:26: warning: no previous prototype
    for ?stoupperx?

    Signed-off-by: Alan Cox
    Acked-by: WANG Cong
    Signed-off-by: James Morris

    Alan Cox
     

24 Oct, 2009

1 commit


07 Oct, 2009

1 commit

  • Add a simple utility (scripts/selinux/genheaders) and invoke it to
    generate the kernel-private class and permission indices in flask.h
    and av_permissions.h automatically during the kernel build from the
    security class mapping definitions in classmap.h. Adding new kernel
    classes and permissions can then be done just by adding them to classmap.h.

    Signed-off-by: Stephen Smalley
    Signed-off-by: James Morris

    Stephen Smalley