On Fri, Jun 21, 2024 at 05:16:56PM +0100, Andrew Cooper wrote:
> `xl devd` has been observed leaking /var/log/xldevd.log into children.
>
> Note this is specifically safe; dup2() leaves O_CLOEXEC disabled on newfd, so
> after setting up stdout/stderr, it's only the logfile fd which will close on
> exec().
>
> 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>
> CC: Oleksii Kurochko <oleksii.kuroc...@gmail.com>
>
> Also entirely speculative based on the QubesOS ticket.
>
> v2:
> * Extend the commit message to explain why stdout/stderr aren't closed by
> this change
>
> For 4.19. This bugfix was posted earlier, but fell between the cracks.
> ---
> 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));
Everytime we use O_CLOEXEC, we add in the C file
#ifndef O_CLOEXEC
#define O_CLOEXEC 0
#endif
we don't need to do that anymore?
Or I guess we'll see if someone complain when they try to build on an
ancien version of Linux.
Acked-by: Anthony PERARD <anthony.per...@vates.tech>
Thanks,
--
Anthony Perard | Vates XCP-ng Developer
XCP-ng & Xen Orchestra - Vates solutions
web: https://vates.tech
