Check for unsupported PD exclusion configuration in dhcpv6_parse_ia
authorBen Hutchings <ben@decadent.org.uk>
Thu, 28 Jan 2016 01:28:32 +0000 (01:28 +0000)
committerBen Hutchings <ben@decadent.org.uk>
Thu, 28 Jan 2016 13:33:46 +0000 (13:33 +0000)
commitabe9d1b0739857f4a0d25005f9f0523153a6fe23
treef910f63502c27178e9ecbbd9d3c6e47e2214d100
parentb0d1c5805a6b76c3b198728cdfd93e351d5eb196
Check for unsupported PD exclusion configuration in dhcpv6_parse_ia

We currently only support PD exclusions that only affect bits 64-95 of
the address, so we require:

    32 <= PD prefix length < exclusion prefix length <= 64

The first inequality was not validated, and this could result in a
buffer overflow when generating the next request message.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
src/dhcpv6.c