1. 15 Jan, 2018 1 commit
    • David Windsor's avatar
      vfs: Copy struct mount.mnt_id to userspace using put_user() · 6391af6f
      David Windsor authored
      The mnt_id field can be copied with put_user(), so there is no need to
      use copy_to_user(). In both cases, hardened usercopy is being bypassed
      since the size is constant, and not open to runtime manipulation.
      
      This patch is verbatim from Brad Spengler/PaX Team's PAX_USERCOPY
      whitelisting code in the last public patch of grsecurity/PaX based on my
      understanding of the code. Changes or omissions from the original code are
      mine and don't reflect the original grsecurity/PaX code.
      Signed-off-by: default avatarDavid Windsor <dave@nullcore.net>
      [kees: adjust commit log]
      Cc: Alexander Viro <viro@zeniv.linux.org.uk>
      Cc: linux-fsdevel@vger.kernel.org
      Signed-off-by: default avatarKees Cook <keescook@chromium.org>
      6391af6f
  2. 02 Nov, 2017 1 commit
    • Greg Kroah-Hartman's avatar
      License cleanup: add SPDX GPL-2.0 license identifier to files with no license · b2441318
      Greg Kroah-Hartman authored
      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 <5
         lines).
      
      All documentation files were explicitly excluded.
      
      The following heuristics were used to determine which SPDX license
      identifiers to apply.
      
       - when both scanners couldn't find any license traces, file was
         considered to have no license information in it, and the top level
         COPYING file license applied.
      
         For non */uapi/* files that summary was:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|-------
         GPL-2.0                                              11139
      
         and resulted in the first patch in this series.
      
         If that file was a */uapi/* path one, it was "GPL-2.0 WITH
         Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|-------
         GPL-2.0 WITH Linux-syscall-note                        930
      
         and resulted in the second patch in this series.
      
       - if a file had some form of licensing information in it, and was one
         of the */uapi/* ones, it was denoted with the Linux-syscall-note if
         any GPL family license was found in the file or had no licensing in
         it (per prior point).  Results summary:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|------
         GPL-2.0 WITH Linux-syscall-note                       270
         GPL-2.0+ WITH Linux-syscall-note                      169
         ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
         ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
         LGPL-2.1+ WITH Linux-syscall-note                      15
         GPL-1.0+ WITH Linux-syscall-note                       14
         ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
         LGPL-2.0+ WITH Linux-syscall-note                       4
         LGPL-2.1 WITH Linux-syscall-note                        3
         ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
         ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1
      
         and that resulted in the third patch in this series.
      
       - when the two scanners agreed on the detected license(s), that became
         the concluded license(s).
      
       - when there was disagreement between the two scanners (one detected a
         license but the other didn't, or they both detected different
         licenses) a manual inspection of the file occurred.
      
       - In most cases a manual inspection of the information in the file
         resulted in a clear resolution of the license that should apply (and
         which scanner probably needed to revisit its heuristics).
      
       - When it was not immediately clear, the license identifier was
         confirmed with lawyers working with the Linux Foundation.
      
       - If there was any question as to the appropriate license identifier,
         the file was flagged for further research and to be revisited later
         in time.
      
      In total, over 70 hours of logged manual review was done on the
      spreadsheet to determine the SPDX license identifiers to apply to the
      source files by Kate, Philippe, Thomas and, in some cases, confirmation
      by lawyers working with the Linux Foundation.
      
      Kate also obtained a third independent scan of the 4.13 code base from
      FOSSology, and compared selected files where the other two scanners
      disagreed against that SPDX file, to see if there was new insights.  The
      Windriver scanner is based on an older version of FOSSology in part, so
      they are related.
      
      Thomas did random spot checks in about 500 files from the spreadsheets
      for the uapi headers and agreed with SPDX license identifier in the
      files he inspected. For the non-uapi files Thomas did random spot checks
      in about 15000 files.
      
      In initial set of patches against 4.14-rc6, 3 files were found to have
      copy/paste license identifier errors, and have been fixed to reflect the
      correct identifier.
      
      Additionally Philippe spent 10 hours this week doing a detailed manual
      inspection and review of the 12,461 patched files from the initial patch
      version early this week with:
       - a full scancode scan run, collecting the matched texts, detected
         license ids and scores
       - reviewing anything where there was a license detected (about 500+
         files) to ensure that the applied SPDX license was correct
       - reviewing anything where there was no detection but the patch license
         was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
         SPDX license was correct
      
      This produced a worksheet with 20 files needing minor correction.  This
      worksheet was then exported into 3 different .csv files for the
      different types of files to be modified.
      
      These .csv files were then reviewed by Greg.  Thomas wrote a script to
      parse the csv files and add the proper SPDX tag to the file, in the
      format that the file expected.  This script was further refined by Greg
      based on the output to detect more types of files automatically and to
      distinguish between header and source .c files (which need different
      comment types.)  Finally Greg ran the script using the .csv files to
      generate the patches.
      Reviewed-by: default avatarKate Stewart <kstewart@linuxfoundation.org>
      Reviewed-by: default avatarPhilippe Ombredanne <pombredanne@nexb.com>
      Reviewed-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b2441318
  3. 14 Oct, 2017 1 commit
  4. 17 Apr, 2017 1 commit
  5. 24 Dec, 2016 1 commit
  6. 22 Mar, 2016 1 commit
    • Jann Horn's avatar
      fs/coredump: prevent fsuid=0 dumps into user-controlled directories · 378c6520
      Jann Horn authored
      This commit fixes the following security hole affecting systems where
      all of the following conditions are fulfilled:
      
       - The fs.suid_dumpable sysctl is set to 2.
       - The kernel.core_pattern sysctl's value starts with "/". (Systems
         where kernel.core_pattern starts with "|/" are not affected.)
       - Unprivileged user namespace creation is permitted. (This is
         true on Linux >=3.8, but some distributions disallow it by
         default using a distro patch.)
      
      Under these conditions, if a program executes under secure exec rules,
      causing it to run with the SUID_DUMP_ROOT flag, then unshares its user
      namespace, changes its root directory and crashes, the coredump will be
      written using fsuid=0 and a path derived from kernel.core_pattern - but
      this path is interpreted relative to the root directory of the process,
      allowing the attacker to control where a coredump will be written with
      root privileges.
      
      To fix the security issue, always interpret core_pattern for dumps that
      are written under SUID_DUMP_ROOT relative to the root directory of init.
      Signed-off-by: default avatarJann Horn <jann@thejh.net>
      Acked-by: default avatarKees Cook <keescook@chromium.org>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: "Eric W. Biederman" <ebiederm@xmission.com>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      378c6520
  7. 02 Jun, 2015 1 commit
    • Sasha Levin's avatar
      vfs: read file_handle only once in handle_to_path · 161f873b
      Sasha Levin authored
      We used to read file_handle twice.  Once to get the amount of extra
      bytes, and once to fetch the entire structure.
      
      This may be problematic since we do size verifications only after the
      first read, so if the number of extra bytes changes in userspace between
      the first and second calls, we'll have an incoherent view of
      file_handle.
      
      Instead, read the constant size once, and copy that over to the final
      structure without having to re-read it again.
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: stable@vger.kernel.org
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      161f873b
  8. 19 Nov, 2012 1 commit
  9. 08 Nov, 2012 1 commit
  10. 27 Sep, 2012 1 commit
  11. 07 Jan, 2012 1 commit
  12. 04 Jan, 2012 1 commit
  13. 14 Apr, 2011 1 commit
  14. 15 Mar, 2011 2 commits