[Bug 3410] New: Since 8.9p1 MaxStartups >=1024, in sshd_config, causes "error: ppoll: Invalid argument"

[bugzilla-daemon at mindrot.org]

https://bugzilla.mindrot.org/show_bug.cgi?id=3410

            Bug ID: 3410
           Summary: Since 8.9p1 MaxStartups >=1024, in sshd_config, causes
                    "error: ppoll: Invalid argument"
           Product: Portable OpenSSH
           Version: 8.9p1
          Hardware: amd64
                OS: Linux
            Status: NEW
          Severity: normal
          Priority: P5
         Component: sshd
          Assignee: unassigned-bugs at mindrot.org
          Reporter: for.github.20200406 at gmx.de

Up to 8.8p1 a value of 4096 for MaxStartups in sshd_config was no
problem.
Since 8.9p1 switched to usage of ppoll(2) the maximum value for
MaxStartups is 1023.

Because this is default ppoll(2) behavior, the expected behavior of
sshd would be:
- the documentation should be updated
- sshd -t should show MaxStartups > 1023 as problem (would have saved
me some time, to identify MaxStartups as problem)
- maybe a MaxStartups > 1023 should be reduced to 1023 internally

PS: Maybe setting such a high value for MaxStartups is the wrong
approach for e.g. allowing a massive threaded app access via ssh, but
it was a working solution (in reality, I had a problem with ~100
unauthenticated connections, setting it to 1023 will be good enough).

-- 
You are receiving this mail because:
You are watching the assignee of the bug.