From cc8bb21c8ad619148c022af6e39ca8a5086a6a88 Mon Sep 17 00:00:00 2001 From: Aurelien Jarno Date: Fri, 30 Nov 2012 15:04:27 -0500 Subject: Fix assertion failures in resolver (BZ #13013). [BZ #13013] * resolv/res_query.c(__libc_res_nquery): Assign hp and hp2 depending n and resplen2 to catch cases where answer equals answerp2. --- resolv/res_query.c | 30 +++++++++++++++--------------- 1 file changed, 15 insertions(+), 15 deletions(-) (limited to 'resolv') diff --git a/resolv/res_query.c b/resolv/res_query.c index abccd4a921..1325f9772d 100644 --- a/resolv/res_query.c +++ b/resolv/res_query.c @@ -122,6 +122,7 @@ __libc_res_nquery(res_state statp, int *resplen2) { HEADER *hp = (HEADER *) answer; + HEADER *hp2; int n, use_malloc = 0; u_int oflags = statp->_flags; @@ -239,26 +240,25 @@ __libc_res_nquery(res_state statp, /* __libc_res_nsend might have reallocated the buffer. */ hp = (HEADER *) *answerp; - /* We simplify the following tests by assigning HP to HP2. It - is easy to verify that this is the same as ignoring all - tests of HP2. */ - HEADER *hp2 = answerp2 ? (HEADER *) *answerp2 : hp; - - if (n < (int) sizeof (HEADER) && answerp2 != NULL - && *resplen2 > (int) sizeof (HEADER)) + /* We simplify the following tests by assigning HP to HP2 or + vice versa. It is easy to verify that this is the same as + ignoring all tests of HP or HP2. */ + if (answerp2 == NULL || *resplen2 < (int) sizeof (HEADER)) { - /* Special case of partial answer. */ - assert (hp != hp2); - hp = hp2; + hp2 = hp; } - else if (answerp2 != NULL && *resplen2 < (int) sizeof (HEADER) - && n > (int) sizeof (HEADER)) + else { - /* Special case of partial answer. */ - assert (hp != hp2); - hp2 = hp; + hp2 = (HEADER *) *answerp2; + if (n < (int) sizeof (HEADER)) + { + hp = hp2; + } } + /* Make sure both hp and hp2 are defined */ + assert((hp != NULL) && (hp2 != NULL)); + if ((hp->rcode != NOERROR || ntohs(hp->ancount) == 0) && (hp2->rcode != NOERROR || ntohs(hp2->ancount) == 0)) { #ifdef DEBUG -- cgit v1.2.3