From 0338934f4bcda6a96a5342449ae96b003de3378d Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Fri, 26 Jul 2019 09:25:09 +0200 Subject: [PATCH] Revert "Revert "sysctl: Enable ping(8) inside rootless Podman containers"" This reverts commit be74f51605b4c7cb74fec3a50cd13b67598a8ac1. Let's add this again. With the new sysctl "-" thing we can make this work. --- NEWS | 9 +++++++++ sysctl.d/50-default.conf | 8 ++++++++ 2 files changed, 17 insertions(+) diff --git a/NEWS b/NEWS index 2a79a2cded8..0049be76caa 100644 --- a/NEWS +++ b/NEWS @@ -2,6 +2,15 @@ systemd System and Service Manager CHANGES WITH 243 in spe: + * This release enables unprivileged programs (i.e. requiring neither + setuid nor file capabilities) to send ICMP Echo (i.e. ping) requests + by turning on the net.ipv4.ping_group_range sysctl of the Linux + kernel for the whole UNIX group range, i.e. all processes. This + change should be reasonably safe, as the kernel support for it was + specifically implemented to allow safe access to ICMP Echo for + processes lacking any privileges. If this is not desirable, it can be + disabled again by setting the parameter to "1 0". + * Previously, filters defined with SystemCallFilter= would have the effect that an calling an offending system call would terminate the calling thread. This behaviour never made much sense, since killing diff --git a/sysctl.d/50-default.conf b/sysctl.d/50-default.conf index 27084f62424..f0b4f610f85 100644 --- a/sysctl.d/50-default.conf +++ b/sysctl.d/50-default.conf @@ -30,6 +30,14 @@ net.ipv4.conf.all.accept_source_route = 0 # Promote secondary addresses when the primary address is removed net.ipv4.conf.all.promote_secondaries = 1 +# ping(8) without CAP_NET_ADMIN and CAP_NET_RAW +# The upper limit is set to 2^31-1. Values greater than that get rejected by +# the kernel because of this definition in linux/include/net/ping.h: +# #define GID_T_MAX (((gid_t)~0U) >> 1) +# That's not so bad because values between 2^31 and 2^32-1 are reserved on +# systemd-based systems anyway: https://systemd.io/UIDS-GIDS.html#summary +net.ipv4.ping_group_range = 0 2147483647 + # Fair Queue CoDel packet scheduler to fight bufferbloat net.core.default_qdisc = fq_codel -- 2.39.2