---
- branch: MAIN
  date: Wed Dec 21 02:28:06 UTC 2022
  files:
  - new: '1.207'
    old: '1.206'
    path: src/sys/uvm/uvm_swap.c
    pathrev: src/sys/uvm/uvm_swap.c@1.207
    type: modified
  id: 20221221T022806Z.234019dfdac0a52a47134b624afb904f56a7a7c3
  log: |
    swap: disallow user opens of swap block device

    the swap/drum block device was never intended to allow user opens,
    but when the internal VOP_OPEN() in uvm_swap_init() was added
    back in rev 1.135, the d_open method was changed from always-fail
    to always-succeed in order to allow the new initial internal open.
    this had the side effect of incorrectly allowing user opens too.
    fix this by replacing the swap_bdevsw d_open with one that succeeds
    for the first call but fails for all subsequent calls.

    Reported-by: syzbot+90a23d2f19e5a0a302b3@syzkaller.appspotmail.com
  module: src
  subject: 'CVS commit: src/sys/uvm'
  unixtime: '1671589686'
  user: chs