[Qemu-devel] question：about pr-helper unlink sock file fail

[wangjie (P)]

Hi, I found there is a bug in pr-helper:

We run pr-helper process in root, and drop all capabilities  expect 
CAP_SYS_RAWIO.

    But the sock file which connect from qemu is owned by qemu group, 
when pr-helper exit,

    it will call  “close_server_socket -> 
object_unref(OBJECT(server_ioc)) -> qio_channel_socket_finalize -> 
socket_listen_cleanup” ,

    unlink sock file  will fail and output “Failed to unlink socket 
xxx, Permission denied”.

    I tried to add capability CAP_DAC_OVERRIDE in pr-helper, it will 
unlink sock success, but I think capability CAP_DAC_OVERRIDE is too 
dangerous.