When handling new connections in 'accept_connections' the number of active connections got increased before the AnyEvent::Handle registered the callback which would decrement it on error.
Any error/die beforehand would skip the decrement, and leave the process in an endless loop upon exiting in wait_end_loop. This can happen e.g. when the call to getpeername fails, or if the connection is denied by the ALLOW_FROM/DENY_FROM settings in '/etc/default/pveproxy' (which is also the simplest reproducer for that). Additionally it can cause a denial of service, by attempting to connect from a denied ip until the connection count exeeds the maximum connections of all child-processes. Reported via our community-forum: https://forum.proxmox.com/threads/pveproxy-eats-available-ram.79617/ Co-Authored-by: Dominik Csapak <d.csa...@proxmox.com> Signed-off-by: Stoiko Ivanov <s.iva...@proxmox.com> --- PVE/APIServer/AnyEvent.pm | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/PVE/APIServer/AnyEvent.pm b/PVE/APIServer/AnyEvent.pm index c55da7f..c5f5fdc 100644 --- a/PVE/APIServer/AnyEvent.pm +++ b/PVE/APIServer/AnyEvent.pm @@ -1479,8 +1479,6 @@ sub accept { fh_nonblocking $clientfh, 1; - $self->{conn_count}++; - return $clientfh; } @@ -1561,7 +1559,7 @@ sub accept_connections { my $reqstate = { keep_alive => $self->{keep_alive} }; # stop keep-alive when there are many open connections - if ($self->{conn_count} >= $self->{max_conn_soft_limit}) { + if ($self->{conn_count}+1 >= $self->{max_conn_soft_limit}) { $reqstate->{keep_alive} = 0; } @@ -1600,6 +1598,9 @@ sub accept_connections { }, ($self->{tls_ctx} ? (tls => "accept", tls_ctx => $self->{tls_ctx}) : ())); + $self->{conn_count}++; + + print "$$: ACCEPT FH" . $clientfh->fileno() . " CONN$self->{conn_count}\n" if $self->{debug}; $self->push_request_header($reqstate); -- 2.20.1 _______________________________________________ pve-devel mailing list pve-devel@lists.proxmox.com https://lists.proxmox.com/cgi-bin/mailman/listinfo/pve-devel