Package: unbound
Version: 1.13.1-1
Severity: normal
Tags: patch
X-Debbugs-Cc: g...@libero.it
Hi
With the apparmor profile shipped with unbound, /usr/sbin/unbound is
allowed to truncate and create its own pidfile /run/unbound.pid, but
cannot remove it at exit or rewrite it when it starts again.
As a consequence, "start-stop-daemon --stop" leaves behind an empty pidfile,
and a subsequent "start-stop-daemon --start" spawns a new daemon whose
pid is written nowhere. The overall result is that N invocations of
"/etc/init.d/unbound restart" end up with N-1 daemons running, with
obvious implications for security.
In #947771 Stephane Lapie and Gedalya suggested a simple patch that
solves the problem. That bug report was closed as "problem solved",
without actually applying the patch, probably because I failed to clearly
explain how to reproduce the issue.
Please, do not close this report unless, on a system managed by
sysvinit-core with apparmor in enforcing mode, exactly one instance of
unbound is left running after invoking "/etc/init.d/unbound restart"
at least four times in a row.
Since 2020, I've been applying the following patch against the script
shipped by the debian package at each new release, again and again.
Hope it can be included for real in the debian tree.
Best regards,
g.
--- /etc/init.d/unbound.dpkg-dist 2021-02-09 23:53:57.000000000 +0100
+++ /etc/init.d/unbound 2022-11-19 08:28:58.429007869 +0100
@@ -42,7 +42,7 @@
stop)
log_daemon_msg "Stopping $DESC" "$NAME"
- if start-stop-daemon --stop --quiet --oknodo --pidfile $PIDFILE --name
$NAME --retry 5; then
+ if start-stop-daemon --stop --quiet --oknodo --remove-pidfile
--pidfile $PIDFILE --name $NAME --retry 5; then
$HELPER resolvconf_stop
$HELPER chroot_teardown
log_end_msg 0
@@ -53,7 +53,7 @@
restart|force-reload)
log_daemon_msg "Restarting $DESC" "$NAME"
- start-stop-daemon --stop --quiet --pidfile $PIDFILE --name $NAME
--retry 5
+ start-stop-daemon --stop --quiet --remove-pidfile --pidfile $PIDFILE
--name $NAME --retry 5
$HELPER resolvconf_stop
if start-stop-daemon --start --quiet --oknodo --pidfile $PIDFILE
--name $NAME --startas $DAEMON -- $DAEMON_OPTS; then
$HELPER chroot_setup
-- System Information:
Debian Release: 11.5
APT prefers stable-updates
APT policy: (500, 'stable-updates'), (500, 'stable-security'), (500, 'stable')
Architecture: amd64 (x86_64)
Kernel: Linux 5.10.0-19-amd64 (SMP w/4 CPU threads)
Locale: LANG=C, LC_CTYPE=C.UTF-8 (charmap=UTF-8), LANGUAGE not set
Shell: /bin/sh linked to /bin/dash
Init: sysvinit (via /sbin/init)
LSM: AppArmor: enabled
Versions of packages unbound depends on:
ii adduser 3.118
ii dns-root-data 2021011101
ii libc6 2.31-13+deb11u5
ii libelogind0 [libsystemd0] 246.9.1-1+debian1
ii libevent-2.1-7 2.1.12-stable-1
ii libprotobuf-c1 1.3.3-1+b2
ii libpython3.9 3.9.2-1
ii libssl1.1 1.1.1n-0+deb11u3
ii lsb-base 11.1.0
ii openssl 1.1.1n-0+deb11u3
ii unbound-anchor 1.13.1-1
unbound recommends no packages.
Versions of packages unbound suggests:
ii apparmor 2.13.6-10
-- no debconf information
