Unexpected behaviour on output redirection after update to 20.04

[ubuntu-users-list at thomas.freit.ag]

Hi Colin,

On 27.04.20 14:57, Colin Watson wrote:
>> since I updated from 19.10 to 20.04 on two machines, I have an unexpected behavior on output redirection, which fails for root (and worked before with 19.10):
>> I would expect, that root could just append to any file on a local filesystem (ext4 in this case). This happens in bash as well.

> The NEWS file for systemd 241 says:
> 
>         * The fs.protected_regular and fs.protected_fifos sysctls, which were
>           added in Linux 4.19 to make some data spoofing attacks harder, are
>           now enabled by default. While this will hopefully improve the
>           security of most installations, it is technically a backwards
>           incompatible change; to disable these sysctls again, place the
>           following lines in /etc/sysctl.d/60-protected.conf or a similar file:
> 
>               fs.protected_regular = 0
>               fs.protected_fifos = 0
> 
>           Note that the similar hardlink and symlink protection has been
>           enabled since v199, and may be disabled likewise.

Thanks Colin, that was exactly the hint I was looking for.

Regards,
Thomas