1. 28 5月, 2020 1 次提交
  2. 27 5月, 2018 1 次提交
  3. 23 5月, 2018 1 次提交
    • A
      procfs: get rid of ancient BS in pid_revalidate() uses · 1bbc5513
      Al Viro 提交于
      First of all, calling pid_revalidate() in the end of <pid>/* lookups
      is *not* about closing any kind of races; that used to be true once
      upon a time, but these days those comments are actively misleading.
      Especially since pid_revalidate() doesn't even do d_drop() on
      failure anymore.  It doesn't matter, anyway, since once
      pid_revalidate() starts returning false, ->d_delete() of those
      dentries starts saying "don't keep"; they won't get stuck in
      dcache any longer than they are pinned.
      
      These calls cannot be just removed, though - the side effect of
      pid_revalidate() (updating i_uid/i_gid/etc.) is what we are calling
      it for here.
      
      Let's separate the "update ownership" into a new helper (pid_update_inode())
      and use it, both in lookups and in pid_revalidate() itself.
      
      The comments in pid_revalidate() are also out of date - they refer to
      the time when pid_revalidate() used to call d_drop() directly...
      Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      1bbc5513
  4. 02 11月, 2017 1 次提交
    • G
      License cleanup: add SPDX GPL-2.0 license identifier to files with no license · b2441318
      Greg Kroah-Hartman 提交于
      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: NKate Stewart <kstewart@linuxfoundation.org>
      Reviewed-by: NPhilippe Ombredanne <pombredanne@nexb.com>
      Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b2441318
  5. 09 5月, 2017 1 次提交
    • K
      pidns: expose task pid_ns_for_children to userspace · eaa0d190
      Kirill Tkhai 提交于
      pid_ns_for_children set by a task is known only to the task itself, and
      it's impossible to identify it from outside.
      
      It's a big problem for checkpoint/restore software like CRIU, because it
      can't correctly handle tasks, that do setns(CLONE_NEWPID) in proccess of
      their work.
      
      This patch solves the problem, and it exposes pid_ns_for_children to ns
      directory in standard way with the name "pid_for_children":
      
        ~# ls /proc/5531/ns -l | grep pid
        lrwxrwxrwx 1 root root 0 Jan 14 16:38 pid -> pid:[4026531836]
        lrwxrwxrwx 1 root root 0 Jan 14 16:38 pid_for_children -> pid:[4026532286]
      
      Link: http://lkml.kernel.org/r/149201123914.6007.2187327078064239572.stgit@localhost.localdomainSigned-off-by: NKirill Tkhai <ktkhai@virtuozzo.com>
      Cc: Andrei Vagin <avagin@virtuozzo.com>
      Cc: Andreas Gruenbacher <agruenba@redhat.com>
      Cc: Kees Cook <keescook@chromium.org>
      Cc: Michael Kerrisk <mtk.manpages@googlemail.com>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Paul Moore <paul@paul-moore.com>
      Cc: Eric Biederman <ebiederm@xmission.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Serge Hallyn <serge@hallyn.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      eaa0d190
  6. 15 11月, 2016 1 次提交
  7. 03 5月, 2016 1 次提交
  8. 17 2月, 2016 1 次提交
    • A
      cgroup: introduce cgroup namespaces · a79a908f
      Aditya Kali 提交于
      Introduce the ability to create new cgroup namespace. The newly created
      cgroup namespace remembers the cgroup of the process at the point
      of creation of the cgroup namespace (referred as cgroupns-root).
      The main purpose of cgroup namespace is to virtualize the contents
      of /proc/self/cgroup file. Processes inside a cgroup namespace
      are only able to see paths relative to their namespace root
      (unless they are moved outside of their cgroupns-root, at which point
       they will see a relative path from their cgroupns-root).
      For a correctly setup container this enables container-tools
      (like libcontainer, lxc, lmctfy, etc.) to create completely virtualized
      containers without leaking system level cgroup hierarchy to the task.
      This patch only implements the 'unshare' part of the cgroupns.
      Signed-off-by: NAditya Kali <adityakali@google.com>
      Signed-off-by: NSerge Hallyn <serge.hallyn@canonical.com>
      Signed-off-by: NTejun Heo <tj@kernel.org>
      a79a908f
  9. 21 1月, 2016 1 次提交
    • J
      ptrace: use fsuid, fsgid, effective creds for fs access checks · caaee623
      Jann Horn 提交于
      By checking the effective credentials instead of the real UID / permitted
      capabilities, ensure that the calling process actually intended to use its
      credentials.
      
      To ensure that all ptrace checks use the correct caller credentials (e.g.
      in case out-of-tree code or newly added code omits the PTRACE_MODE_*CREDS
      flag), use two new flags and require one of them to be set.
      
      The problem was that when a privileged task had temporarily dropped its
      privileges, e.g.  by calling setreuid(0, user_uid), with the intent to
      perform following syscalls with the credentials of a user, it still passed
      ptrace access checks that the user would not be able to pass.
      
      While an attacker should not be able to convince the privileged task to
      perform a ptrace() syscall, this is a problem because the ptrace access
      check is reused for things in procfs.
      
      In particular, the following somewhat interesting procfs entries only rely
      on ptrace access checks:
      
       /proc/$pid/stat - uses the check for determining whether pointers
           should be visible, useful for bypassing ASLR
       /proc/$pid/maps - also useful for bypassing ASLR
       /proc/$pid/cwd - useful for gaining access to restricted
           directories that contain files with lax permissions, e.g. in
           this scenario:
           lrwxrwxrwx root root /proc/13020/cwd -> /root/foobar
           drwx------ root root /root
           drwxr-xr-x root root /root/foobar
           -rw-r--r-- root root /root/foobar/secret
      
      Therefore, on a system where a root-owned mode 6755 binary changes its
      effective credentials as described and then dumps a user-specified file,
      this could be used by an attacker to reveal the memory layout of root's
      processes or reveal the contents of files he is not allowed to access
      (through /proc/$pid/cwd).
      
      [akpm@linux-foundation.org: fix warning]
      Signed-off-by: NJann Horn <jann@thejh.net>
      Acked-by: NKees Cook <keescook@chromium.org>
      Cc: Casey Schaufler <casey@schaufler-ca.com>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: James Morris <james.l.morris@oracle.com>
      Cc: "Serge E. Hallyn" <serge.hallyn@ubuntu.com>
      Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: "Eric W. Biederman" <ebiederm@xmission.com>
      Cc: Willy Tarreau <w@1wt.eu>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      caaee623
  10. 31 12月, 2015 1 次提交
  11. 09 12月, 2015 1 次提交
    • A
      replace ->follow_link() with new method that could stay in RCU mode · 6b255391
      Al Viro 提交于
      new method: ->get_link(); replacement of ->follow_link().  The differences
      are:
      	* inode and dentry are passed separately
      	* might be called both in RCU and non-RCU mode;
      the former is indicated by passing it a NULL dentry.
      	* when called that way it isn't allowed to block
      and should return ERR_PTR(-ECHILD) if it needs to be called
      in non-RCU mode.
      
      It's a flagday change - the old method is gone, all in-tree instances
      converted.  Conversion isn't hard; said that, so far very few instances
      do not immediately bail out when called in RCU mode.  That'll change
      in the next commits.
      Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      6b255391
  12. 11 5月, 2015 2 次提交
    • A
      don't pass nameidata to ->follow_link() · 6e77137b
      Al Viro 提交于
      its only use is getting passed to nd_jump_link(), which can obtain
      it from current->nameidata
      Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      6e77137b
    • A
      new ->follow_link() and ->put_link() calling conventions · 680baacb
      Al Viro 提交于
      a) instead of storing the symlink body (via nd_set_link()) and returning
      an opaque pointer later passed to ->put_link(), ->follow_link() _stores_
      that opaque pointer (into void * passed by address by caller) and returns
      the symlink body.  Returning ERR_PTR() on error, NULL on jump (procfs magic
      symlinks) and pointer to symlink body for normal symlinks.  Stored pointer
      is ignored in all cases except the last one.
      
      Storing NULL for opaque pointer (or not storing it at all) means no call
      of ->put_link().
      
      b) the body used to be passed to ->put_link() implicitly (via nameidata).
      Now only the opaque pointer is.  In the cases when we used the symlink body
      to free stuff, ->follow_link() now should store it as opaque pointer in addition
      to returning it.
      Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      680baacb
  13. 16 4月, 2015 1 次提交
  14. 11 12月, 2014 2 次提交
    • A
      kill proc_ns completely · 3d3d35b1
      Al Viro 提交于
      procfs inodes need only the ns_ops part; nsfs inodes don't need it at all
      Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      3d3d35b1
    • A
      take the targets of /proc/*/ns/* symlinks to separate fs · e149ed2b
      Al Viro 提交于
      New pseudo-filesystem: nsfs.  Targets of /proc/*/ns/* live there now.
      It's not mountable (not even registered, so it's not in /proc/filesystems,
      etc.).  Files on it *are* bindable - we explicitly permit that in do_loopback().
      
      This stuff lives in fs/nsfs.c now; proc_ns_fget() moved there as well.
      get_proc_ns() is a macro now (it's simply returning ->i_private; would
      have been an inline, if not for header ordering headache).
      proc_ns_inode() is an ex-parrot.  The interface used in procfs is
      ns_get_path(path, task, ops) and ns_get_name(buf, size, task, ops).
      
      Dentries and inodes are never hashed; a non-counting reference to dentry
      is stashed in ns_common (removed by ->d_prune()) and reused by ns_get_path()
      if present.  See ns_get_path()/ns_prune_dentry/nsfs_evict() for details
      of that mechanism.
      
      As the result, proc_ns_follow_link() has stopped poking in nd->path.mnt;
      it does nd_jump_link() on a consistent <vfsmount,dentry> pair it gets
      from ns_get_path().
      Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      e149ed2b
  15. 05 12月, 2014 2 次提交
  16. 02 4月, 2014 1 次提交
  17. 16 11月, 2013 1 次提交
  18. 29 6月, 2013 2 次提交
  19. 02 5月, 2013 1 次提交
  20. 09 3月, 2013 1 次提交
    • E
      proc: Use nd_jump_link in proc_ns_follow_link · db04dc67
      Eric W. Biederman 提交于
      Update proc_ns_follow_link to use nd_jump_link instead of just
      manually updating nd.path.dentry.
      
      This fixes the BUG_ON(nd->inode != parent->d_inode) reported by Dave
      Jones and reproduced trivially with mkdir /proc/self/ns/uts/a.
      
      Sigh it looks like the VFS change to require use of nd_jump_link
      happend while proc_ns_follow_link was baking and since the common case
      of proc_ns_follow_link continued to work without problems the need for
      making this change was overlooked.
      
      Cc: stable@vger.kernel.org
      Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
      db04dc67
  21. 20 11月, 2012 3 次提交
    • E
      proc: Usable inode numbers for the namespace file descriptors. · 98f842e6
      Eric W. Biederman 提交于
      Assign a unique proc inode to each namespace, and use that
      inode number to ensure we only allocate at most one proc
      inode for every namespace in proc.
      
      A single proc inode per namespace allows userspace to test
      to see if two processes are in the same namespace.
      
      This has been a long requested feature and only blocked because
      a naive implementation would put the id in a global space and
      would ultimately require having a namespace for the names of
      namespaces, making migration and certain virtualization tricks
      impossible.
      
      We still don't have per superblock inode numbers for proc, which
      appears necessary for application unaware checkpoint/restart and
      migrations (if the application is using namespace file descriptors)
      but that is now allowd by the design if it becomes important.
      
      I have preallocated the ipc and uts initial proc inode numbers so
      their structures can be statically initialized.
      Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
      98f842e6
    • E
      proc: Fix the namespace inode permission checks. · bf056bfa
      Eric W. Biederman 提交于
      Change the proc namespace files into symlinks so that
      we won't cache the dentries for the namespace files
      which can bypass the ptrace_may_access checks.
      
      To support the symlinks create an additional namespace
      inode with it's own set of operations distinct from the
      proc pid inode and dentry methods as those no longer
      make sense.
      Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
      bf056bfa
    • E
      userns: Implent proc namespace operations · cde1975b
      Eric W. Biederman 提交于
      This allows entering a user namespace, and the ability
      to store a reference to a user namespace with a bind
      mount.
      
      Addition of missing userns_ns_put in userns_install
      from Gao feng <gaofeng@cn.fujitsu.com>
      Acked-by: NSerge Hallyn <serge.hallyn@canonical.com>
      Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
      cde1975b
  22. 19 11月, 2012 2 次提交
    • E
      vfs: Add setns support for the mount namespace · 8823c079
      Eric W. Biederman 提交于
      setns support for the mount namespace is a little tricky as an
      arbitrary decision must be made about what to set fs->root and
      fs->pwd to, as there is no expectation of a relationship between
      the two mount namespaces.  Therefore I arbitrarily find the root
      mount point, and follow every mount on top of it to find the top
      of the mount stack.  Then I set fs->root and fs->pwd to that
      location.  The topmost root of the mount stack seems like a
      reasonable place to be.
      
      Bind mount support for the mount namespace inodes has the
      possibility of creating circular dependencies between mount
      namespaces.  Circular dependencies can result in loops that
      prevent mount namespaces from every being freed.  I avoid
      creating those circular dependencies by adding a sequence number
      to the mount namespace and require all bind mounts be of a
      younger mount namespace into an older mount namespace.
      
      Add a helper function proc_ns_inode so it is possible to
      detect when we are attempting to bind mound a namespace inode.
      Acked-by: NSerge Hallyn <serge.hallyn@canonical.com>
      Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
      8823c079
    • E
      pidns: Add setns support · 57e8391d
      Eric W. Biederman 提交于
      - Pid namespaces are designed to be inescapable so verify that the
        passed in pid namespace is a child of the currently active
        pid namespace or the currently active pid namespace itself.
      
        Allowing the currently active pid namespace is important so
        the effects of an earlier setns can be cancelled.
      Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
      57e8391d
  23. 14 7月, 2012 2 次提交
  24. 29 3月, 2012 1 次提交
  25. 24 3月, 2012 1 次提交
  26. 04 1月, 2012 1 次提交
  27. 16 6月, 2011 1 次提交
  28. 25 5月, 2011 1 次提交
  29. 11 5月, 2011 4 次提交