On Mon, Aug 30, 2021 at 09:29:14PM +0000, Andy Smith wrote: > Hello, > > On Mon, Aug 30, 2021 at 05:07:16PM -0400, Greg Wooledge wrote: > > unicorn:~$ strace bash -c 'echo stuff >> /tmp/123' > > [...] > > openat(AT_FDCWD, "/tmp/123", O_WRONLY|O_CREAT|O_APPEND, 0666) = -1 EACCES > > (Permission denied) > > > > As far as I can see, this is a kernel bug. Unless I'm overlooking > > something...? > > I think it's the sysctl fs.protected_regular: > > https://unix.stackexchange.com/a/503169
I think you're right. The changed behavior doesn't happen in /srv (only in /tmp), nor does it happen on a buster system. According to <https://www.spinics.net/lists/fedora-devel/msg252453.html> and <https://github.com/systemd/systemd/blob/main/NEWS>, the change actually happened in... wait for it... systemd. *sigh*