From 1c0ab5bd34159d2ae53390571113844ebadc161b Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Thu, 16 Jul 2009 23:37:50 -0700 Subject: [PATCH] Handle overly large answer buffers in resolver. In EDNS0 records the maximum result size is transmitted in a 16 bit value. Large buffer sizes were handled incorrectly by using only the low 16 bits. Fix this by limiting the size to 0xffff. --- ChangeLog | 6 ++++++ resolv/res_mkquery.c | 2 +- 2 files changed, 7 insertions(+), 1 deletion(-) diff --git a/ChangeLog b/ChangeLog index 37f20a4..7dab061 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,9 @@ +2009-07-16 Ulrich Drepper + + [BZ #10360] + * resolv/res-mkquery.c (__res_nopt): If anslen is > 0xffff store + 0xffff in the EDNS0 record. + 2009-07-16 Petr Baudis * nscd/mem.c (mempool_alloc): Fix unlock missing in the else branch. diff --git a/resolv/res_mkquery.c b/resolv/res_mkquery.c index ae0cdb4..2dda4c0 100644 --- a/resolv/res_mkquery.c +++ b/resolv/res_mkquery.c @@ -244,7 +244,7 @@ __res_nopt(res_state statp, *cp++ = 0; /* "." */ NS_PUT16(T_OPT, cp); /* TYPE */ - NS_PUT16(anslen & 0xffff, cp); /* CLASS = UDP payload size */ + NS_PUT16(MIN(anslen, 0xffff), cp); /* CLASS = UDP payload size */ *cp++ = NOERROR; /* extended RCODE */ *cp++ = 0; /* EDNS version */ /* XXX Once we support DNSSEC we change the flag value here. */ -- 2.7.4