Bug#1025820: Bug: grub-pc 2.06-3~deb10u3 upgrade assumes /tmp is exec

[Steve McIntyre]

Control: reassign -1 debconf

Hi!

On Fri, Dec 09, 2022 at 03:54:34PM -0500, imschmeg wrote:
>Package: grub-pc
>Version: 2.06-3~deb10u3
>
>The error message during an "apt upgrade" that includes grub-pc is:
>
>open2: exec of /tmp/grub-pc.config.ajRf2i configure 2.06-3~deb10u2
>failed: Permission denied at /usr/share/perl5/Debconf/ConfModule.pm
>line 59. 
>
>The problem is that apt upgrade assumes /tmp is mounted exec.  Common
>security practice is to mount /tmp noexec, which I do.
>
>Apt install scripts could instead be executed without being exec by
>passing them as a parameter to the shell command.
>
>Also, after the error, the apt upgrade finished instead of aborting,
>leaving my system in an unknown state.  I had to remount /tmp with exec
>and reinstall the grub packages.

This really isn't a grub bug - AFAICS what you're seeing here would
happen with any package that's doing upgrades and uses debconf for
configuration. I don't think this behaviour is necessarily a bug
personally, but I'm reassigning this to debconf...

-- 
Steve McIntyre, Cambridge, UK.                                steve at einval.com
"This dress doesn't reverse." -- Alden Spiess