bind CVE-2012-1667 Upstream-Status: Backport ISC BIND 9.x before 9.7.6-P1, 9.8.x before 9.8.3-P1, 9.9.x before 9.9.1-P1, and 9.4-ESV and 9.6-ESV before 9.6-ESV-R7-P1 does not properly handle resource records with a zero-length RDATA section, which allows remote DNS servers to cause a denial of service (daemon crash or data corruption) or obtain sensitive information from process memory via a crafted record. http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2012-1667 The cve patch comes from bind97-9.7.0-10.P2.el5_8.1.src.rpm package. Signed-off-by: Li Wang --- lib/dns/rdata.c | 8 ++++---- lib/dns/rdataslab.c | 11 ++++++++--- 2 files changed, 12 insertions(+), 7 deletions(-) diff --git a/lib/dns/rdata.c b/lib/dns/rdata.c index 063b1f6..9337a80 100644 --- a/lib/dns/rdata.c +++ b/lib/dns/rdata.c @@ -325,8 +325,8 @@ dns_rdata_compare(const dns_rdata_t *rdata1, const dns_rdata_t *rdata2) { REQUIRE(rdata1 != NULL); REQUIRE(rdata2 != NULL); - REQUIRE(rdata1->data != NULL); - REQUIRE(rdata2->data != NULL); + REQUIRE(rdata1->length == 0 || rdata1->data != NULL); + REQUIRE(rdata2->length == 0 || rdata2->data != NULL); REQUIRE(DNS_RDATA_VALIDFLAGS(rdata1)); REQUIRE(DNS_RDATA_VALIDFLAGS(rdata2)); @@ -356,8 +356,8 @@ dns_rdata_casecompare(const dns_rdata_t *rdata1, const dns_rdata_t *rdata2) { REQUIRE(rdata1 != NULL); REQUIRE(rdata2 != NULL); - REQUIRE(rdata1->data != NULL); - REQUIRE(rdata2->data != NULL); + REQUIRE(rdata1->length == 0 || rdata1->data != NULL); + REQUIRE(rdata2->length == 0 || rdata2->data != NULL); REQUIRE(DNS_RDATA_VALIDFLAGS(rdata1)); REQUIRE(DNS_RDATA_VALIDFLAGS(rdata2)); diff --git a/lib/dns/rdataslab.c b/lib/dns/rdataslab.c index a41f16f..ed13b30 100644 --- a/lib/dns/rdataslab.c +++ b/lib/dns/rdataslab.c @@ -125,6 +125,11 @@ isc_result_t dns_rdataslab_fromrdataset(dns_rdataset_t *rdataset, isc_mem_t *mctx, isc_region_t *region, unsigned int reservelen) { + /* + * Use &removed as a sentinal pointer for duplicate + * rdata as rdata.data == NULL is valid. + */ + static unsigned char removed; struct xrdata *x; unsigned char *rawbuf; #if DNS_RDATASET_FIXED @@ -168,6 +173,7 @@ dns_rdataslab_fromrdataset(dns_rdataset_t *rdataset, isc_mem_t *mctx, INSIST(result == ISC_R_SUCCESS); dns_rdata_init(&x[i].rdata); dns_rdataset_current(rdataset, &x[i].rdata); + INSIST(x[i].rdata.data != &removed); #if DNS_RDATASET_FIXED x[i].order = i; #endif @@ -200,8 +206,7 @@ dns_rdataslab_fromrdataset(dns_rdataset_t *rdataset, isc_mem_t *mctx, */ for (i = 1; i < nalloc; i++) { if (compare_rdata(&x[i-1].rdata, &x[i].rdata) == 0) { - x[i-1].rdata.data = NULL; - x[i-1].rdata.length = 0; + x[i-1].rdata.data = &removed; #if DNS_RDATASET_FIXED /* * Preserve the least order so A, B, A -> A, B @@ -291,7 +296,7 @@ dns_rdataslab_fromrdataset(dns_rdataset_t *rdataset, isc_mem_t *mctx, #endif for (i = 0; i < nalloc; i++) { - if (x[i].rdata.data == NULL) + if (x[i].rdata.data == &removed) continue; #if DNS_RDATASET_FIXED offsettable[x[i].order] = rawbuf - offsetbase; -- 1.7.0.5