Package: systemd Version: 236-3 Severity: normal Tags: upstream Dear Maintainer,
on an 32 bit arm system when the RTC is set to a wrong time booting the system might fail because systemd gets stuck in a loop printing "systemd[1]: Time has been changed". The problem is known upstream and claimed to be a problem of the kernel: https://github.com/systemd/systemd/issues/1143 However, while upstream is certainly correct that a kernel bug is the trigger of the lockup, systemd should not hang on this, because if sending messages to systemd can lock up the system then this is actually an attack vector for a DoS attack. A approach to work around this problem is posted in above bug report by user wtarreau and repeated here (comment included): Basically manager_clock_watch() could start with something more or less like this (assuming it's the one responsible for this endless loop) : gettimeofday(&now, NULL); if (m->last_change == now.tv_sec) { m->change_count++; } else { if (m->change_count > 1) log("Time changed %d times in the last second\n", m->change_count); if (m->change_count >= 100) { log("Timerfd is broken on this system, disabling time change detection\n"); manager_listen_stop(m); return 0; } m->change_count = 0; m->last_change = now.tv_sec; } Best, Gert -- Package-specific info: -- System Information: Debian Release: buster/sid APT prefers testing APT policy: (500, 'testing') Architecture: armhf (armv7l) Kernel: Linux 4.15.1-cm-fx6-my (SMP w/4 CPU cores; PREEMPT) Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=ANSI_X3.4-1968) (ignored: LC_ALL set to C), LANGUAGE=en_US.UTF-8 (charmap=ANSI_X3.4-1968) (ignored: LC_ALL set to C) Shell: /bin/sh linked to /bin/dash Init: systemd (via /run/systemd/system) Versions of packages systemd depends on: ii adduser 3.117 ii libacl1 2.2.52-3+b1 ii libapparmor1 2.12-2 ii libaudit1 1:2.8.2-1 ii libblkid1 2.30.2-0.3 ii libc6 2.26-6 ii libcap2 1:2.25-1.2 ii libcryptsetup4 2:1.7.5-1 ii libgcrypt20 1.8.1-4 ii libgpg-error0 1.27-6 ii libidn11 1.33-2.1 ii libip4tc0 1.6.2-1 ii libkmod2 25-1 ii liblz4-1 0.0~r131-2+b1 ii liblzma5 5.2.2-1.3 ii libmount1 2.30.2-0.3 ii libpam0g 1.1.8-3.7 ii libseccomp2 2.3.1-2.1 ii libselinux1 2.7-2+b1 ii libsystemd0 236-3 ii mount 2.30.2-0.3 ii procps 2:3.3.12-3 ii util-linux 2.30.2-0.3 Versions of packages systemd recommends: ii dbus 1.12.4-1 ii libpam-systemd 236-3 Versions of packages systemd suggests: ii policykit-1 0.105-18 pn systemd-container <none> Versions of packages systemd is related to: pn dracut <none> pn initramfs-tools <none> ii udev 236-3 -- no debconf information