1. 27 Nov, 2017 15 commits
  2. 07 Nov, 2017 8 commits
    • Andrew Elble's avatar
      nfsd: deal with revoked delegations appropriately · 95da1b3a
      Andrew Elble authored
      If a delegation has been revoked by the server, operations using that
      delegation should error out with NFS4ERR_DELEG_REVOKED in the >4.1
      case, and NFS4ERR_BAD_STATEID otherwise.
      
      The server needs NFSv4.1 clients to explicitly free revoked delegations.
      If the server returns NFS4ERR_DELEG_REVOKED, the client will do that;
      otherwise it may just forget about the delegation and be unable to
      recover when it later sees SEQ4_STATUS_RECALLABLE_STATE_REVOKED set on a
      SEQUENCE reply.  That can cause the Linux 4.1 client to loop in its
      stage manager.
      Signed-off-by: 's avatarAndrew Elble <aweits@rit.edu>
      Reviewed-by: 's avatarTrond Myklebust <trond.myklebust@primarydata.com>
      Cc: stable@vger.kernel.org
      Signed-off-by: 's avatarJ. Bruce Fields <bfields@redhat.com>
      95da1b3a
    • Vasily Averin's avatar
      nfsd: use nfs->ns.inum as net ID · 7e981a8a
      Vasily Averin authored
      Publishing of net pointer is not safe,
      let's use nfs->ns.inum instead
      Signed-off-by: 's avatarVasily Averin <vvs@virtuozzo.com>
      Signed-off-by: 's avatarJ. Bruce Fields <bfields@redhat.com>
      7e981a8a
    • Arnd Bergmann's avatar
      nfds: avoid gettimeofday for nfssvc_boot time · 256a89fa
      Arnd Bergmann authored
      do_gettimeofday() is deprecated and we should generally use time64_t
      based functions instead.
      
      In case of nfsd, all three users of nfssvc_boot only use the initial
      time as a unique token, and are not affected by it overflowing, so they
      are not affected by the y2038 overflow.
      
      This converts the structure to timespec64 anyway and adds comments
      to all uses, to document that we have thought about it and avoid
      having to look at it again.
      Signed-off-by: 's avatarArnd Bergmann <arnd@arndb.de>
      Signed-off-by: 's avatarJ. Bruce Fields <bfields@redhat.com>
      256a89fa
    • Elena Reshetova's avatar
      fs, nfsd: convert nfs4_file.fi_ref from atomic_t to refcount_t · 818a34eb
      Elena Reshetova authored
      atomic_t variables are currently used to implement reference
      counters with the following properties:
       - counter is initialized to 1 using atomic_set()
       - a resource is freed upon counter reaching zero
       - once counter reaches zero, its further
         increments aren't allowed
       - counter schema uses basic atomic operations
         (set, inc, inc_not_zero, dec_and_test, etc.)
      
      Such atomic variables should be converted to a newly provided
      refcount_t type and API that prevents accidental counter overflows
      and underflows. This is important since overflows and underflows
      can lead to use-after-free situation and be exploitable.
      
      The variable nfs4_file.fi_ref is used as pure reference counter.
      Convert it to refcount_t and fix up the operations.
      Suggested-by: 's avatarKees Cook <keescook@chromium.org>
      Reviewed-by: 's avatarDavid Windsor <dwindsor@gmail.com>
      Reviewed-by: 's avatarHans Liljestrand <ishkamiel@gmail.com>
      Signed-off-by: 's avatarElena Reshetova <elena.reshetova@intel.com>
      Signed-off-by: 's avatarJ. Bruce Fields <bfields@redhat.com>
      818a34eb
    • Elena Reshetova's avatar
      fs, nfsd: convert nfs4_cntl_odstate.co_odcount from atomic_t to refcount_t · cff7cb2e
      Elena Reshetova authored
      atomic_t variables are currently used to implement reference
      counters with the following properties:
       - counter is initialized to 1 using atomic_set()
       - a resource is freed upon counter reaching zero
       - once counter reaches zero, its further
         increments aren't allowed
       - counter schema uses basic atomic operations
         (set, inc, inc_not_zero, dec_and_test, etc.)
      
      Such atomic variables should be converted to a newly provided
      refcount_t type and API that prevents accidental counter overflows
      and underflows. This is important since overflows and underflows
      can lead to use-after-free situation and be exploitable.
      
      The variable nfs4_cntl_odstate.co_odcount is used as pure reference counter.
      Convert it to refcount_t and fix up the operations.
      Suggested-by: 's avatarKees Cook <keescook@chromium.org>
      Reviewed-by: 's avatarDavid Windsor <dwindsor@gmail.com>
      Reviewed-by: 's avatarHans Liljestrand <ishkamiel@gmail.com>
      Signed-off-by: 's avatarElena Reshetova <elena.reshetova@intel.com>
      Signed-off-by: 's avatarJ. Bruce Fields <bfields@redhat.com>
      cff7cb2e
    • Elena Reshetova's avatar
      fs, nfsd: convert nfs4_stid.sc_count from atomic_t to refcount_t · a15dfcd5
      Elena Reshetova authored
      atomic_t variables are currently used to implement reference
      counters with the following properties:
       - counter is initialized to 1 using atomic_set()
       - a resource is freed upon counter reaching zero
       - once counter reaches zero, its further
         increments aren't allowed
       - counter schema uses basic atomic operations
         (set, inc, inc_not_zero, dec_and_test, etc.)
      
      Such atomic variables should be converted to a newly provided
      refcount_t type and API that prevents accidental counter overflows
      and underflows. This is important since overflows and underflows
      can lead to use-after-free situation and be exploitable.
      
      The variable nfs4_stid.sc_count is used as pure reference counter.
      Convert it to refcount_t and fix up the operations.
      Suggested-by: 's avatarKees Cook <keescook@chromium.org>
      Reviewed-by: 's avatarDavid Windsor <dwindsor@gmail.com>
      Reviewed-by: 's avatarHans Liljestrand <ishkamiel@gmail.com>
      Signed-off-by: 's avatarElena Reshetova <elena.reshetova@intel.com>
      Signed-off-by: 's avatarJ. Bruce Fields <bfields@redhat.com>
      a15dfcd5
    • J. Bruce Fields's avatar
      nfsd4: catch some false session retries · 53da6a53
      J. Bruce Fields authored
      The spec allows us to return NFS4ERR_SEQ_FALSE_RETRY if we notice that
      the client is making a call that matches a previous (slot, seqid) pair
      but that *isn't* actually a replay, because some detail of the call
      doesn't actually match the previous one.
      
      Catching every such case is difficult, but we may as well catch a few
      easy ones.  This also handles the case described in the previous patch,
      in a different way.
      
      The spec does however require us to catch the case where the difference
      is in the rpc credentials.  This prevents somebody from snooping another
      user's replies by fabricating retries.
      
      (But the practical value of the attack is limited by the fact that the
      replies with the most sensitive data are READ replies, which are not
      normally cached.)
      Tested-by: 's avatarOlga Kornievskaia <aglo@umich.edu>
      Signed-off-by: 's avatarJ. Bruce Fields <bfields@redhat.com>
      53da6a53
    • J. Bruce Fields's avatar
      nfsd4: fix cached replies to solo SEQUENCE compounds · 085def3a
      J. Bruce Fields authored
      Currently our handling of 4.1+ requests without "cachethis" set is
      confusing and not quite correct.
      
      Suppose a client sends a compound consisting of only a single SEQUENCE
      op, and it matches the seqid in a session slot (so it's a retry), but
      the previous request with that seqid did not have "cachethis" set.
      
      The obvious thing to do might be to return NFS4ERR_RETRY_UNCACHED_REP,
      but the protocol only allows that to be returned on the op following the
      SEQUENCE, and there is no such op in this case.
      
      The protocol permits us to cache replies even if the client didn't ask
      us to.  And it's easy to do so in the case of solo SEQUENCE compounds.
      
      So, when we get a solo SEQUENCE, we can either return the previously
      cached reply or NFSERR_SEQ_FALSE_RETRY if we notice it differs in some
      way from the original call.
      
      Currently, we're returning a corrupt reply in the case a solo SEQUENCE
      matches a previous compound with more ops.  This actually matters
      because the Linux client recently started doing this as a way to recover
      from lost replies to idempotent operations in the case the process doing
      the original reply was killed: in that case it's difficult to keep the
      original arguments around to do a real retry, and the client no longer
      cares what the result is anyway, but it would like to make sure that the
      slot's sequence id has been incremented, and the solo SEQUENCE assures
      that: if the server never got the original reply, it will increment the
      sequence id.  If it did get the original reply, it won't increment, and
      nothing else that about the reply really matters much.  But we can at
      least attempt to return valid xdr!
      Tested-by: 's avatarOlga Kornievskaia <aglo@umich.edu>
      Signed-off-by: 's avatarJ. Bruce Fields <bfields@redhat.com>
      085def3a
  3. 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: 's avatarKate Stewart <kstewart@linuxfoundation.org>
      Reviewed-by: 's avatarPhilippe Ombredanne <pombredanne@nexb.com>
      Reviewed-by: 's avatarThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: 's avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b2441318
  4. 05 Oct, 2017 2 commits
    • Eryu Guan's avatar
      nfsd4: define nfsd4_secinfo_no_name_release() · ec572b9e
      Eryu Guan authored
      Commit 34b1744c ("nfsd4: define ->op_release for compound ops")
      defined a couple ->op_release functions and run them if necessary.
      
      But there's a problem with that is that it reused
      nfsd4_secinfo_release() as the op_release of OP_SECINFO_NO_NAME, and
      caused a leak on struct nfsd4_secinfo_no_name in
      nfsd4_encode_secinfo_no_name(), because there's no .si_exp field in
      struct nfsd4_secinfo_no_name.
      
      I found this because I was unable to umount an ext4 partition after
      exporting it via NFS & run fsstress on the nfs mount. A simplified
      reproducer would be:
      
       # mount a local-fs device at /mnt/test, and export it via NFS with
       # fsid=0 export option (this is required)
       mount /dev/sda5 /mnt/test
       echo "/mnt/test *(rw,no_root_squash,fsid=0)" >> /etc/exports
       service nfs restart
      
       # locally mount the nfs export with all default, note that I have
       # nfsv4.1 configured as the default nfs version, because of the
       # fsid export option, v4 mount would fail and fall back to v3
       mount localhost:/mnt/test /mnt/nfs
      
       # try to umount the underlying device, but got EBUSY
       umount /mnt/nfs
       service nfs stop
       umount /mnt/test <=== EBUSY here
      
      Fixed it by defining a separate nfsd4_secinfo_no_name_release()
      function as the op_release method of OP_SECINFO_NO_NAME that
      releases the correct nfsd4_secinfo_no_name structure.
      
      Fixes: 34b1744c ("nfsd4: define ->op_release for compound ops")
      Signed-off-by: 's avatarEryu Guan <eguan@redhat.com>
      Signed-off-by: 's avatarJ. Bruce Fields <bfields@redhat.com>
      ec572b9e
    • Jérémy Lefaure's avatar
      nfsd: use ARRAY_SIZE · a133552a
      Jérémy Lefaure authored
      Using the ARRAY_SIZE macro improves the readability of the code.
      
      Found with Coccinelle with the following semantic patch:
      @r depends on (org || report)@
      type T;
      T[] E;
      position p;
      @@
      (
       (sizeof(E)@p /sizeof(*E))
      |
       (sizeof(E)@p /sizeof(E[...]))
      |
       (sizeof(E)@p /sizeof(T))
      )
      Signed-off-by: 's avatarJérémy Lefaure <jeremy.lefaure@lse.epita.fr>
      Reviewed-by: 's avatarJeff Layton <jlayton@redhat.com>
      Signed-off-by: 's avatarJ. Bruce Fields <bfields@redhat.com>
      a133552a
  5. 04 Oct, 2017 3 commits
  6. 01 Oct, 2017 1 commit
  7. 05 Sep, 2017 1 commit
    • Chuck Lever's avatar
      nfsd: Incoming xdr_bufs may have content in tail buffer · eae03e2a
      Chuck Lever authored
      Since the beginning, svcsock has built a received RPC Call message
      by populating the xdr_buf's head, then placing the remaining
      message bytes in the xdr_buf's page list. The xdr_buf's tail is
      never populated.
      
      This means that an NFSv4 COMPOUND containing an NFS WRITE operation
      plus trailing operations has a page list that contains the WRITE
      data payload followed by the trailing operations. NFSv4 XDR decoders
      will not look in the xdr_buf's tail, ever, because svcsock never put
      anything there.
      
      To support transports that can pass the write payload in the
      xdr_buf's pagelist and trailing content in the xdr_buf's tail,
      introduce logic in READ_BUF that switches to the xdr_buf's tail vec
      when the decoder runs out of content in rq_arg.pages.
      Signed-off-by: 's avatarChuck Lever <chuck.lever@oracle.com>
      Signed-off-by: 's avatarJ. Bruce Fields <bfields@redhat.com>
      eae03e2a
  8. 31 Aug, 2017 1 commit
  9. 25 Aug, 2017 6 commits
  10. 24 Aug, 2017 1 commit
    • Chuck Lever's avatar
      nfsd: Limit end of page list when decoding NFSv4 WRITE · fc788f64
      Chuck Lever authored
      When processing an NFSv4 WRITE operation, argp->end should never
      point past the end of the data in the final page of the page list.
      Otherwise, nfsd4_decode_compound can walk into uninitialized memory.
      
      More critical, nfsd4_decode_write is failing to increment argp->pagelen
      when it increments argp->pagelist.  This can cause later xdr decoders
      to assume more data is available than really is, which can cause server
      crashes on malformed requests.
      Signed-off-by: 's avatarChuck Lever <chuck.lever@oracle.com>
      Cc: stable@vger.kernel.org
      Signed-off-by: 's avatarJ. Bruce Fields <bfields@redhat.com>
      fc788f64
  11. 01 Aug, 2017 1 commit