Thanks for chasing that down. Your patch will fix it, but I think it's probably better to solve the problem at source, where we copy addresses out of packets, rather than pass unaligned pointers to struct in6_addr around and patch things up at the other end. That stops this coming and biting us again.
That makes a much bigger patch, unfortunately. I just pushed my attempt at doing that. Does it work OK for you? Cheers, Simon. On 21/08/18 14:04, Vladislav Grishenko wrote: > Hi, Simon > > > > Faced with dnsmasq crash on aarch64 (32bit userspace, > arm-buildroot-linux-gnueabi-gcc 5.3.0) with dhcpv6 stateful configured. > > Unaligned packet’s req_addr is used in lease6_allocate() for struct copy > since 2.67test15 (commit 89500e31f199e9ae1eadc86213b911ff44d30d6f). > > As for other places, seems well-aligned stack-local vars are used. > > Please refer proposed patch attached and gdb trace: > > > > Program received signal SIGBUS, Bus error. > > 0x0003f990 in lease6_allocate (addrp=0xa55e6, lease_type=32) at lease.c:822 > > 822 lease->addr6 = *addrp; > > (gdb) bt > > #0 0x0003f990 in lease6_allocate (addrp=0xa55e6, lease_type=32) at > lease.c:822 > > #1 0x00055fac in update_leases (state=0xfffef8ac, context=0xa7ee8, > addr=0xa55e6, lease_time=900, now=14609) at rfc3315.c:1825 > > #2 0x00055ab4 in add_address (state=0xfffef8ac, context=0xa7ee8, > lease_time=900, ia_option=0xa55e2, min_time=0xfffef6d0, addr=0xa55e6, > now=14609) at rfc3315.c:1684 > > #3 0x00053764 in dhcp6_no_relay (state=0xfffef8ac, msg_type=3, > inbuff=0xa55a8, sz=128, is_unicast=0, now=14609) at rfc3315.c:938 > > #4 0x00051744 in dhcp6_maybe_relay (state=0xfffef8ac, inbuff=0xa55a8, > sz=128, client_addr=0xfffef9a0, is_unicast=0, now=14609) at rfc3315.c:172 > > #5 0x000513b8 in dhcp6_reply (context=0xa7ee8, interface=23, > iface_name=0xfffef978, fallback=0xfffef9f8, ll_addr=0xfffefa18, > ula_addr=0xfffefa28, sz=128, client_addr=0xfffef9a0, > > now=14609) at rfc3315.c:103 > > #6 0x0004f4b4 in dhcp6_packet (now=14609) at dhcp6.c:233 > > #7 0x00038c78 in main (argc=3, argv=0xfffefd34) at dnsmasq.c:1099 > > > > Best Regards, Vladislav Grishenko > > > _______________________________________________ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss