1. 13 Apr, 2018 1 commit
  2. 09 Apr, 2018 1 commit
    • Amir Goldstein's avatar
      fanotify: fix logic of events on child · 54a307ba
      Amir Goldstein authored
      When event on child inodes are sent to the parent inode mark and
      parent inode mark was not marked with FAN_EVENT_ON_CHILD, the event
      will not be delivered to the listener process. However, if the same
      process also has a mount mark, the event to the parent inode will be
      delivered regadless of the mount mark mask.
      
      This behavior is incorrect in the case where the mount mark mask does
      not contain the specific event type. For example, the process adds
      a mark on a directory with mask FAN_MODIFY (without FAN_EVENT_ON_CHILD)
      and a mount mark with mask FAN_CLOSE_NOWRITE (without FAN_ONDIR).
      
      A modify event on a file inside that directory (and inside that mount)
      should not create a FAN_MODIFY event, because neither of the marks
      requested to get that event on the file.
      
      Fixes: 1968f5ee ("fanotify: use both marks when possible")
      Cc: stable <stable@vger.kernel.org>
      Signed-off-by: Amir Goldstein's avatarAmir Goldstein <amir73il@gmail.com>
      Signed-off-by: default avatarJan Kara <jack@suse.cz>
      54a307ba
  3. 02 Apr, 2018 2 commits
  4. 27 Feb, 2018 2 commits
    • Jan Kara's avatar
      fsnotify: Let userspace know about lost events due to ENOMEM · 7b1f6417
      Jan Kara authored
      Currently if notification event is lost due to event allocation failing
      we ENOMEM, we just silently continue (except for fanotify permission
      events where we deny the access). This is undesirable as userspace has
      no way of knowing whether the notifications it got are complete or not.
      Treat lost events due to ENOMEM the same way as lost events due to queue
      overflow so that userspace knows something bad happened and it likely
      needs to rescan the filesystem.
      Reviewed-by: Amir Goldstein's avatarAmir Goldstein <amir73il@gmail.com>
      Signed-off-by: default avatarJan Kara <jack@suse.cz>
      7b1f6417
    • Jan Kara's avatar
      fanotify: Avoid lost events due to ENOMEM for unlimited queues · 1f5eaa90
      Jan Kara authored
      Fanotify queues of unlimited length do not expect events can be lost.
      Since these queues are used for system auditing and other security
      related tasks, loosing events can even have security implications.
      Currently, since the allocation is small (32-bytes), it cannot fail
      however when we start accounting events in memcgs, allocation can start
      failing. So avoid loosing events due to failure to allocate memory by
      making event allocation use __GFP_NOFAIL.
      Reviewed-by: Amir Goldstein's avatarAmir Goldstein <amir73il@gmail.com>
      Signed-off-by: default avatarJan Kara <jack@suse.cz>
      1f5eaa90
  5. 14 Feb, 2018 1 commit
    • Kirill Tkhai's avatar
      inotify: Extend ioctl to allow to request id of new watch descriptor · e1603b6e
      Kirill Tkhai authored
      Watch descriptor is id of the watch created by inotify_add_watch().
      It is allocated in inotify_add_to_idr(), and takes the numbers
      starting from 1. Every new inotify watch obtains next available
      number (usually, old + 1), as served by idr_alloc_cyclic().
      
      CRIU (Checkpoint/Restore In Userspace) project supports inotify
      files, and restores watched descriptors with the same numbers,
      they had before dump. Since there was no kernel support, we
      had to use cycle to add a watch with specific descriptor id:
      
      	while (1) {
      		int wd;
      
      		wd = inotify_add_watch(inotify_fd, path, mask);
      		if (wd < 0) {
      			break;
      		} else if (wd == desired_wd_id) {
      			ret = 0;
      			break;
      		}
      
      		inotify_rm_watch(inotify_fd, wd);
      	}
      
      (You may find the actual code at the below link:
       https://github.com/checkpoint-restore/criu/blob/v3.7/criu/fsnotify.c#L577)
      
      The cycle is suboptiomal and very expensive, but since there is no better
      kernel support, it was the only way to restore that. Happily, we had met
      mostly descriptors with small id, and this approach had worked somehow.
      
      But recent time containers with inotify with big watch descriptors
      begun to come, and this way stopped to work at all. When descriptor id
      is something about 0x34d71d6, the restoring process spins in busy loop
      for a long time, and the restore hungs and delay of migration from node
      to node could easily be watched.
      
      This patch aims to solve this problem. It introduces new ioctl
      INOTIFY_IOC_SETNEXTWD, which allows to request the number of next created
      watch descriptor from userspace. It simply calls idr_set_cursor() primitive
      to populate idr::idr_next, so that next idr_alloc_cyclic() allocation
      will return this id, if it is not occupied. This is the way which is
      used to restore some other resources from userspace. For example,
      /proc/sys/kernel/ns_last_pid works the same for task pids.
      
      The new code is under CONFIG_CHECKPOINT_RESTORE #define, so small system
      may exclude it.
      
      v2: Use INT_MAX instead of custom definition of max id,
      as IDR subsystem guarantees id is between 0 and INT_MAX.
      
      CC: Jan Kara <jack@suse.cz>
      CC: Matthew Wilcox <willy@infradead.org>
      CC: Andrew Morton <akpm@linux-foundation.org>
      CC: Amir Goldstein <amir73il@gmail.com>
      Signed-off-by: default avatarKirill Tkhai <ktkhai@virtuozzo.com>
      Reviewed-by: default avatarCyrill Gorcunov <gorcunov@openvz.org>
      Reviewed-by: default avatarMatthew Wilcox <mawilcox@microsoft.com>
      Reviewed-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarJan Kara <jack@suse.cz>
      e1603b6e
  6. 11 Feb, 2018 1 commit
    • Linus Torvalds's avatar
      vfs: do bulk POLL* -> EPOLL* replacement · a9a08845
      Linus Torvalds authored
      This is the mindless scripted replacement of kernel use of POLL*
      variables as described by Al, done by this script:
      
          for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do
              L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'`
              for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done
          done
      
      with de-mangling cleanups yet to come.
      
      NOTE! On almost all architectures, the EPOLL* constants have the same
      values as the POLL* constants do.  But they keyword here is "almost".
      For various bad reasons they aren't the same, and epoll() doesn't
      actually work quite correctly in some cases due to this on Sparc et al.
      
      The next patch from Al will sort out the final differences, and we
      should be all done.
      Scripted-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      a9a08845
  7. 27 Nov, 2017 2 commits
    • Al Viro's avatar
      fs: annotate ->poll() instances · 076ccb76
      Al Viro authored
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      076ccb76
    • Linus Torvalds's avatar
      Rename superblock flags (MS_xyz -> SB_xyz) · 1751e8a6
      Linus Torvalds authored
      This is a pure automated search-and-replace of the internal kernel
      superblock flags.
      
      The s_flags are now called SB_*, with the names and the values for the
      moment mirroring the MS_* flags that they're equivalent to.
      
      Note how the MS_xyz flags are the ones passed to the mount system call,
      while the SB_xyz flags are what we then use in sb->s_flags.
      
      The script to do this was:
      
          # places to look in; re security/*: it generally should *not* be
          # touched (that stuff parses mount(2) arguments directly), but
          # there are two places where we really deal with superblock flags.
          FILES="drivers/mtd drivers/staging/lustre fs ipc mm \
                  include/linux/fs.h include/uapi/linux/bfs_fs.h \
                  security/apparmor/apparmorfs.c security/apparmor/include/lib.h"
          # the list of MS_... constants
          SYMS="RDONLY NOSUID NODEV NOEXEC SYNCHRONOUS REMOUNT MANDLOCK \
                DIRSYNC NOATIME NODIRATIME BIND MOVE REC VERBOSE SILENT \
                POSIXACL UNBINDABLE PRIVATE SLAVE SHARED RELATIME KERNMOUNT \
                I_VERSION STRICTATIME LAZYTIME SUBMOUNT NOREMOTELOCK NOSEC BORN \
                ACTIVE NOUSER"
      
          SED_PROG=
          for i in $SYMS; do SED_PROG="$SED_PROG -e s/MS_$i/SB_$i/g"; done
      
          # we want files that contain at least one of MS_...,
          # with fs/namespace.c and fs/pnode.c excluded.
          L=$(for i in $SYMS; do git grep -w -l MS_$i $FILES; done| sort|uniq|grep -v '^fs/namespace.c'|grep -v '^fs/pnode.c')
      
          for f in $L; do sed -i $f $SED_PROG; done
      Requested-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      1751e8a6
  8. 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
  9. 31 Oct, 2017 10 commits
  10. 12 Oct, 2017 1 commit
  11. 10 Oct, 2017 1 commit
    • Steve Grubb's avatar
      audit: Record fanotify access control decisions · de8cd83e
      Steve Grubb authored
      The fanotify interface allows user space daemons to make access
      control decisions. Under common criteria requirements, we need to
      optionally record decisions based on policy. This patch adds a bit mask,
      FAN_AUDIT, that a user space daemon can 'or' into the response decision
      which will tell the kernel that it made a decision and record it.
      
      It would be used something like this in user space code:
      
        response.response = FAN_DENY | FAN_AUDIT;
        write(fd, &response, sizeof(struct fanotify_response));
      
      When the syscall ends, the audit system will record the decision as a
      AUDIT_FANOTIFY auxiliary record to denote that the reason this event
      occurred is the result of an access control decision from fanotify
      rather than DAC or MAC policy.
      
      A sample event looks like this:
      
      type=PATH msg=audit(1504310584.332:290): item=0 name="./evil-ls"
      inode=1319561 dev=fc:03 mode=0100755 ouid=1000 ogid=1000 rdev=00:00
      obj=unconfined_u:object_r:user_home_t:s0 nametype=NORMAL
      type=CWD msg=audit(1504310584.332:290): cwd="/home/sgrubb"
      type=SYSCALL msg=audit(1504310584.332:290): arch=c000003e syscall=2
      success=no exit=-1 a0=32cb3fca90 a1=0 a2=43 a3=8 items=1 ppid=901
      pid=959 auid=1000 uid=1000 gid=1000 euid=1000 suid=1000
      fsuid=1000 egid=1000 sgid=1000 fsgid=1000 tty=pts1 ses=3 comm="bash"
      exe="/usr/bin/bash" subj=unconfined_u:unconfined_r:unconfined_t:
      s0-s0:c0.c1023 key=(null)
      type=FANOTIFY msg=audit(1504310584.332:290): resp=2
      
      Prior to using the audit flag, the developer needs to call
      fanotify_init or'ing in FAN_ENABLE_AUDIT to ensure that the kernel
      supports auditing. The calling process must also have the CAP_AUDIT_WRITE
      capability.
      Signed-off-by: default avatarsgrubb <sgrubb@redhat.com>
      Reviewed-by: Amir Goldstein's avatarAmir Goldstein <amir73il@gmail.com>
      Signed-off-by: default avatarJan Kara <jack@suse.cz>
      de8cd83e
  12. 30 Aug, 2017 1 commit
  13. 08 Jul, 2017 1 commit
    • Al Viro's avatar
      dentry name snapshots · 49d31c2f
      Al Viro authored
      take_dentry_name_snapshot() takes a safe snapshot of dentry name;
      if the name is a short one, it gets copied into caller-supplied
      structure, otherwise an extra reference to external name is grabbed
      (those are never modified).  In either case the pointer to stable
      string is stored into the same structure.
      
      dentry must be held by the caller of take_dentry_name_snapshot(),
      but may be freely dropped afterwards - the snapshot will stay
      until destroyed by release_dentry_name_snapshot().
      
      Intended use:
      	struct name_snapshot s;
      
      	take_dentry_name_snapshot(&s, dentry);
      	...
      	access s.name
      	...
      	release_dentry_name_snapshot(&s);
      
      Replaces fsnotify_oldname_...(), gets used in fsnotify to obtain the name
      to pass down with event.
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      49d31c2f
  14. 25 Apr, 2017 1 commit
    • Amir Goldstein's avatar
      fanotify: don't expose EOPENSTALE to userspace · 4ff33aaf
      Amir Goldstein authored
      When delivering an event to userspace for a file on an NFS share,
      if the file is deleted on server side before user reads the event,
      user will not get the event.
      
      If the event queue contained several events, the stale event is
      quietly dropped and read() returns to user with events read so far
      in the buffer.
      
      If the event queue contains a single stale event or if the stale
      event is a permission event, read() returns to user with the kernel
      internal error code 518 (EOPENSTALE), which is not a POSIX error code.
      
      Check the internal return value -EOPENSTALE in fanotify_read(), just
      the same as it is checked in path_openat() and drop the event in the
      cases that it is not already dropped.
      
      This is a reproducer from Marko Rauhamaa:
      
      Just take the example program listed under "man fanotify" ("fantest")
      and follow these steps:
      
          ==============================================================
          NFS Server    NFS Client(1)     NFS Client(2)
          ==============================================================
          # echo foo >/nfsshare/bar.txt
                        # cat /nfsshare/bar.txt
                        foo
                                          # ./fantest /nfsshare
                                          Press enter key to terminate.
                                          Listening for events.
          # rm -f /nfsshare/bar.txt
                        # cat /nfsshare/bar.txt
                                          read: Unknown error 518
                        cat: /nfsshare/bar.txt: Operation not permitted
          ==============================================================
      
      where NFS Client (1) and (2) are two terminal sessions on a single NFS
      Client machine.
      Reported-by: default avatarMarko Rauhamaa <marko.rauhamaa@f-secure.com>
      Tested-by: default avatarMarko Rauhamaa <marko.rauhamaa@f-secure.com>
      Cc: <linux-api@vger.kernel.org>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: Amir Goldstein's avatarAmir Goldstein <amir73il@gmail.com>
      Signed-off-by: default avatarJan Kara <jack@suse.cz>
      4ff33aaf
  15. 24 Apr, 2017 1 commit
  16. 10 Apr, 2017 13 commits