When set/restore sysctl value, we should quote the value as some keys may have multi values, e.g. net.ipv4.ping_group_range Fixes: f5ae57784ba8 ("selftests: forwarding: lib: Add sysctl_set(), sysctl_restore()") Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> Reviewed-by: Petr Machata <petrm@nvidia.com> Link: https://lore.kernel.org/r/20230208032110.879205-1-liuhangbin@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>