[Midnightbsd-cvs] [MidnightBSD/src] 425adb: A particular case of memory sharing is mishandled ...

[Lucas Holt]

  Branch: refs/heads/master
  Home:   https://github.com/MidnightBSD/src
  Commit: 425adbac6e8e206e3869293fc821eba05279cfd8
      https://github.com/MidnightBSD/src/commit/425adbac6e8e206e3869293fc821eba05279cfd8
  Author: Lucas Holt <luke at foolishgames.com>
  Date:   2021-04-06 (Tue, 06 Apr 2021)

  Changed paths:
    M sys/vm/vm_fault.c

  Log Message:
  -----------
  A particular case of memory sharing is mishandled in the virtual memory
system.  It is possible and legal to establish a relationship where
multiple descendant processes share a mapping which shadows memory of an
ancestor process.  In this scenario, when one process modifies memory
through such a mapping, the copy-on-write logic fails to invalidate
other mappings of the source page.  These stale mappings may remain even
after the mapped pages have been reused for another purpose.

Obtained from: FreeBSD


  Commit: 47ae3537e18258f82f47e2aec8d2974265991e82
      https://github.com/MidnightBSD/src/commit/47ae3537e18258f82f47e2aec8d2974265991e82
  Author: Lucas Holt <luke at foolishgames.com>
  Date:   2021-04-06 (Tue, 06 Apr 2021)

  Changed paths:
    M UPDATING

  Log Message:
  -----------
  document change


  Commit: 568fb025252d7aadf44544955cbbffe7e786f7e6
      https://github.com/MidnightBSD/src/commit/568fb025252d7aadf44544955cbbffe7e786f7e6
  Author: Lucas Holt <luke at foolishgames.com>
  Date:   2021-04-06 (Tue, 06 Apr 2021)

  Changed paths:
    M sys/kern/vfs_mount.c

  Log Message:
  -----------
  Due to a race condition between lookup of ".." and remounting a filesystem,
a process running inside a jail might access filesystem hierarchy outside
of jail.

Obtained from: FreeBSD


  Commit: 44cdf5fd37115eb6ec2a1a5de794521d7722fe06
      https://github.com/MidnightBSD/src/commit/44cdf5fd37115eb6ec2a1a5de794521d7722fe06
  Author: Lucas Holt <luke at foolishgames.com>
  Date:   2021-04-06 (Tue, 06 Apr 2021)

  Changed paths:
    M UPDATING

  Log Message:
  -----------
  document


Compare: https://github.com/MidnightBSD/src/compare/9bf8258bbc26...44cdf5fd3711