1. 04 Jan, 2009 1 commit
    • Li Zefan's avatar
      cgroups: fix a race between cgroup_clone and umount · 7b574b7b
      Li Zefan authored
      The race is calling cgroup_clone() while umounting the ns cgroup subsys,
      and thus cgroup_clone() might access invalid cgroup_fs, or kill_sb() is
      called after cgroup_clone() created a new dir in it.
      The BUG I triggered is BUG_ON(root->number_of_cgroups != 1);
        ------------[ cut here ]------------
        kernel BUG at kernel/cgroup.c:1093!
        invalid opcode: 0000 [#1] SMP
        Process umount (pid: 5177, ti=e411e000 task=e40c4670 task.ti=e411e000)
        Call Trace:
         [<c0493df7>] ? deactivate_super+0x3f/0x51
         [<c04a3600>] ? mntput_no_expire+0xb3/0xdd
         [<c04a3ab2>] ? sys_umount+0x265/0x2ac
         [<c04a3b06>] ? sys_oldumount+0xd/0xf
         [<c0403911>] ? sysenter_do_call+0x12/0x31
        EIP: [<c0456e76>] cgroup_kill_sb+0x23/0xe0 SS:ESP 0068:e411ef2c
        ---[ end trace c766c1be3bf944ac ]---
      Cc: Serge E. Hallyn <serue@us.ibm.com>
      Signed-off-by: default avatarLi Zefan <lizf@cn.fujitsu.com>
      Cc: Paul Menage <menage@google.com>
      Cc: "Serge E. Hallyn" <serue@us.ibm.com>
      Cc: Balbir Singh <balbir@in.ibm.com>
      Cc: <stable@kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
  2. 03 Jan, 2009 39 commits