On Tue, Aug 19, 2008 at 11:10:49PM +0200, Jim Meyering wrote: > "Daniel P. Berrange" <berrange@xxxxxxxxxx> wrote: > > On Tue, Aug 19, 2008 at 10:51:29PM +0200, Jim Meyering wrote: > >> "Daniel P. Berrange" <berrange@xxxxxxxxxx> wrote: > >> > Some of the existing usage of fork/exec in libvirt is done such that the > >> > child process is daemonized. In particular the libvirt_proxy and the > >> > auto-spawned libvirtd for qemu:///session. Since we want to switch these > >> > to use virExec, we need to suport a daemon mode. > >> > > >> > This patch removes the two alternate virExec and virExecNonBlock functions > >> > and renames the internal __virExec to virExec. It then gains a 'flags' > >> > parameter which can be used to specify non-blocking mode, or daemon mode. > >> > > >> > We also add the ability to pass in a list of environment variables which > >> > get passed on to execve(). We also now explicitly close all file handles. > >> > Although libvirt code is careful to set O_CLOSEXEC on all its file handles, > >> > in multi-threaded apps there is a race condition between opening a FD and > >> > setting O_CLOSEXEC. Furthermore, we can't guarentee that all applications > >> > using libvirt are careful to set O_CLOSEXEC. Leaking FDs to a child is a > >> > potential security risk and often causes SELinux AVCs to be raised. Thus > >> > explicitely closing all FDs is a important safety net. > >> > >> How about closing those FDs in the child instead, right after the fork? > >> Then, if a virExec caller has an open socket or file descriptor, > >> it won't be closed behind its back. > > > > This is being done after a fork(). The diff context in this patch is > > a little misleading. The fork() shown here is the 2nd optional fork() done > > in daemon mode. The first fork() is higher up before we close the FDs. > > I should have known. Next time I'll review with the full context. > ACK, then. Ok, committed now. Daniel -- |: Red Hat, Engineering, London -o- http://people.redhat.com/berrange/ :| |: http://libvirt.org -o- http://virt-manager.org -o- http://ovirt.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: GnuPG: 7D3B9505 -o- F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 :| -- Libvir-list mailing list Libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list