On Tue, May 07, 2024 at 03:15:48PM +0100, Andrew Cooper wrote: > On 07/05/2024 12:32 pm, Marek Marczykowski-Górecki wrote: > > On Tue, May 07, 2024 at 12:08:06PM +0100, Andrew Cooper wrote: > >> `xl devd` has been observed leaking /var/log/xldevd.log into children. > >> > >> Link: https://github.com/QubesOS/qubes-issues/issues/8292 > >> Reported-by: Demi Marie Obenour <d...@invisiblethingslab.com> > >> Signed-off-by: Andrew Cooper <andrew.coop...@citrix.com> > >> --- > >> CC: Anthony PERARD <anth...@xenproject.org> > >> CC: Juergen Gross <jgr...@suse.com> > >> CC: Demi Marie Obenour <d...@invisiblethingslab.com> > >> CC: Marek Marczykowski-Górecki <marma...@invisiblethingslab.com> > >> > >> Also entirely speculative based on the QubesOS ticket. > >> --- > >> tools/xl/xl_utils.c | 2 +- > >> 1 file changed, 1 insertion(+), 1 deletion(-) > >> > >> diff --git a/tools/xl/xl_utils.c b/tools/xl/xl_utils.c > >> index 17489d182954..060186db3a59 100644 > >> --- a/tools/xl/xl_utils.c > >> +++ b/tools/xl/xl_utils.c > >> @@ -270,7 +270,7 @@ int do_daemonize(const char *name, const char *pidfile) > >> exit(-1); > >> } > >> > >> - CHK_SYSCALL(logfile = open(fullname, O_WRONLY|O_CREAT|O_APPEND, > >> 0644)); > >> + CHK_SYSCALL(logfile = open(fullname, O_WRONLY | O_CREAT | O_APPEND | > >> O_CLOEXEC, 0644)); > > This one might be not enough, as the FD gets dup2()-ed to stdout/stderr > > just outside of the context here, and then inherited by various hotplug > > script. Just adding O_CLOEXEC here means the hotplug scripts will run > > with stdout/stderr closed. > > Lovely :( Yes - this won't work. I guess what we want instead is: > > diff --git a/tools/xl/xl_utils.c b/tools/xl/xl_utils.c > index 060186db3a59..a0ce7dd7fa21 100644 > --- a/tools/xl/xl_utils.c > +++ b/tools/xl/xl_utils.c > @@ -282,6 +282,7 @@ int do_daemonize(const char *name, const char *pidfile) > dup2(logfile, 2); > > close(nullfd); > + close(logfile); > > CHK_SYSCALL(daemon(0, 1)); > > which at least means there's not a random extra fd attached to the logfile.
But logfile is a global variable, and it looks to be used in dolog()... -- Best Regards, Marek Marczykowski-Górecki Invisible Things Lab
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