On Wed, Aug 06, 2025 at 04:23:43PM -0000, Michael van Elst wrote: > That is probably a sudo issue. By default sudo acts as a tty > emulator like:
> |-+= 01407 root login > | \-+= 00692 root -sh > | \-+= 00975 root sudo -s > | \-+= 00983 root sudo -s > | \--= 00989 root /bin/sh > > Where the outer sudo reads raw tty input and should pass input > to the started command. However: > > [fstat output elided] > > The started command (sh) has only open file handles to the console. > > In the ssh case: > > -+= 00942 root -sh > \-+= 01631 root sudo -s > \-+= 01528 root sudo -s > \--= 00977 root /bin/sh > > [fstat output elided] > > The started command is connected to the new pty opened by sudo and > receives the data that the outer sudo writes to it. Thanks for analyzing this. That explains it. > N.B. you could avoid this by disabling the pty mode in sudoers. The release notes for sudo 1.9.17rc1 (https://www.sudo.ws/releases/devel/#1.9.17rc1) mention: * Fixed a problem running sudo from a serial console on Linux when the command is run in a pseudo-terminal (the default). I just updated sudo on the vm to 1.9.17.p1 (the latest binary package the configured repo) and the bug is gone. "sudo -s" from the console now works as expected. --chris
