Package: dhcp-client Version: 2.0pl5-19.3 Severity: important In common/packet.c in rotine decode_udp_ip_header there is an pointer set without looking for alignment: ip = (struct ip *)(buf + bufix); Later a field is copied to another place: memcpy (&from -> sin_addr, &ip -> ip_src, 4); This seems to be optimized to a direct copy of an integer (which I think is legal, as this pointer has to be aligned to be accessed to gcc may assume it also if for memcpy)
When I run dhclient on this UltraSparc 2 I unsuprisingly get a bus error at this position (it's more suprising that it runs that long and does not receives signals on all architectures but i386 all the time) The attached patch fixes this problem for me. Though I suggest to let someone experienced with writing code for processors with alignment retraints take a look into it, as similar "tricks" seem to be used at other places, too. Bernhard R. Link -- System Information: Debian Release: testing/unstable APT prefers unstable APT policy: (500, 'unstable') Architecture: sparc (sparc64) Shell: /bin/sh linked to /bin/bash Kernel: Linux 2.6.8-2-sparc64 Locale: LANG=en_US, LC_CTYPE=en_US (charmap=ISO-8859-1) Versions of packages dhcp-client depends on: ii libc6 2.3.5-8 GNU C Library: Shared libraries an Versions of other related packages: ii gcc 4.0.2-1 The GNU C compiler diff -r -u dhcp-2.0pl5/common/packet.c dhcp.new/common/packet.c --- dhcp-2.0pl5/common/packet.c 1999-06-10 02:58:16.000000000 +0200 +++ dhcp.new/common/packet.c 2005-12-02 20:20:17.380854320 +0100 @@ -229,8 +229,11 @@ static int udp_packets_length_checked; static int udp_packets_length_overflow; int len; + struct ip ip_copy; - ip = (struct ip *)(buf + bufix); + ip = &ip_copy; + memcpy(ip,buf+bufix,sizeof(struct ip)); + udp = (struct udphdr *)(buf + bufix + ip_len); #ifdef USERLAND_FILTER
diff -r -u dhcp-2.0pl5/common/packet.c dhcp.new/common/packet.c --- dhcp-2.0pl5/common/packet.c 1999-06-10 02:58:16.000000000 +0200 +++ dhcp.new/common/packet.c 2005-12-02 20:20:17.380854320 +0100 @@ -229,8 +229,11 @@ static int udp_packets_length_checked; static int udp_packets_length_overflow; int len; + struct ip ip_copy; - ip = (struct ip *)(buf + bufix); + ip = &ip_copy; + memcpy(ip,buf+bufix,sizeof(struct ip)); + udp = (struct udphdr *)(buf + bufix + ip_len); #ifdef USERLAND_FILTER
