Package: isc-dhcp-client Version: 4.3.2-1 Tags: patch Followup-For: Bug #768860
Dear Maintainer, The immediate cause of this issue seem to be, that in file /etc/dhcp/dhclient-exit-hooks.d/rfc3442-classless-routes the "shift <n>" commands perform no actual shift and leaves the positional arguments as before. the bash manual explains: > shift [n] > If n is greater than $#, the positional parameters are not > changed. My patch attached to this email proposes to check for this condition and abort the script. Although the issue should be resolved by this, no attempts are made to further mitigate the effect of bogus dhcp option 121 sent by the dhcp server (I think a bogus rfc-3442 option should be ignore entirely). As a further note: I would like to write an error message to system log (in the patch it's only written to stderr and thus does not reach syslog). Although /usr/bin/logger seems to be the perfect tool, I am unsure regarding support/presence of this tool on non-debian operating systems (i.e. *BSD)) -- System Information: Debian Release: stretch/sid APT prefers stable APT policy: (990, 'stable'), (500, 'stable-updates'), (500, 'unstable') Architecture: amd64 (x86_64) Foreign Architectures: i386 Kernel: Linux 4.0.0-1-amd64 (SMP w/4 CPU cores) Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8) Shell: /bin/sh linked to /bin/dash Init: systemd (via /run/systemd/system) Versions of packages isc-dhcp-client depends on: ii debianutils 4.4+b1 ii iproute2 3.16.0-2 ii isc-dhcp-common 4.3.1-6 ii libc6 2.19-18 ii libdns-export100 1:9.9.5.dfsg-9 ii libirs-export91 1:9.9.5.dfsg-9 ii libisc-export95 1:9.9.5.dfsg-9 isc-dhcp-client recommends no packages. Versions of packages isc-dhcp-client suggests: ii avahi-autoipd 0.6.31-5 pn resolvconf <none> -- no debconf information
diff -urNp isc-dhcp-client_4.3.2-1_amd64.old/etc/dhcp/dhclient-exit-hooks.d/rfc3442-classless-routes isc-dhcp-client_4.3.2-1_amd64/etc/dhcp/dhclient-exit-hooks.d/rfc3442-classless-routes
--- isc-dhcp-client_4.3.2-1_amd64.old/etc/dhcp/dhclient-exit-hooks.d/rfc3442-classless-routes 2015-06-18 19:39:50.532165415 +0200
+++ isc-dhcp-client_4.3.2-1_amd64/etc/dhcp/dhclient-exit-hooks.d/rfc3442-classless-routes 2015-06-18 14:39:53.908765610 +0200
@@ -7,6 +7,9 @@
RUN="yes"
+rfc3442_msg() {
+ echo "Illegal rfc3442 classless static route option parameters" >&2
+}
if [ "$RUN" = "yes" ]; then
if [ -n "$new_rfc3442_classless_static_routes" ]; then
@@ -22,26 +25,31 @@ if [ "$RUN" = "yes" ]; then
32|31|30|29|28|27|26|25)
net_address="${2}.${3}.${4}.${5}"
gateway="${6}.${7}.${8}.${9}"
+ [ $# -ge 9 ] || { rfc3442_msg; return 1; }
shift 9
;;
24|23|22|21|20|19|18|17)
net_address="${2}.${3}.${4}.0"
gateway="${5}.${6}.${7}.${8}"
+ [ $# -ge 8 ] || { rfc3442_msg; return 1; }
shift 8
;;
16|15|14|13|12|11|10|9)
net_address="${2}.${3}.0.0"
gateway="${4}.${5}.${6}.${7}"
+ [ $# -ge 7 ] || { rfc3442_msg; return 1; }
shift 7
;;
8|7|6|5|4|3|2|1)
net_address="${2}.0.0.0"
gateway="${3}.${4}.${5}.${6}"
+ [ $# -ge 6 ] || { rfc3442_msg; return 1; }
shift 6
;;
0) # default route
net_address="0.0.0.0"
gateway="${2}.${3}.${4}.${5}"
+ [ $# -ge 5 ] || { rfc3442_msg; return 1; }
shift 5
;;
*) # error
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