I found the same behaviour as the bug-opener and did some additional research. For me it looks like, that this issue only get visible, when starting sslh not under the control of systemd. Systemd grabs the filehandles from the daemon, so when systemd takes control, the problem is not visible. I documented my tests in https://github.com/yrutschle/sslh/issues/467 Furthermore I added an PR (https://github.com/yrutschle/sslh/issues/468) to sslh, closing the three std-handles when daemonizing in background.
--- To the debian maintainer: I added three weeks ago another important patch, to sslh, which is described here: https://github.com/yrutschle/sslh/blob/master/doc/Daisy-Chaining-Transparency-Explained.md This is something, which should be part of an upcoming debian version, as this allows combining multiple transparent-ip tools, like nginx and sslh. stunnel has unfortunately the same problem, sslh had before this patch. I provided also an patch to the stunnel-project, but received no answer yet. https://www.stunnel.org/mailman3/hyperkitty/list/[email protected]/thread/ZSRTZF3YE7N5XNLTFK2V23PD4IRMPHLW/ Sicher versendet mit [Proton Mail](https://proton.me/).
