diff options
| -rw-r--r-- | ChangeLog | 14 | ||||
| -rw-r--r-- | NEWS | 8 | ||||
| -rw-r--r-- | include/arpa/nameser_compat.h | 6 | ||||
| -rw-r--r-- | resolv/Makefile | 3 | ||||
| -rw-r--r-- | resolv/nss_dns/dns-host.c | 2 | ||||
| -rw-r--r-- | resolv/res_mkquery.c | 4 | ||||
| -rw-r--r-- | resolv/res_query.c | 6 | ||||
| -rw-r--r-- | resolv/tst-resolv-qtypes.c | 185 |
8 files changed, 220 insertions, 8 deletions
diff --git a/ChangeLog b/ChangeLog index 01ee23b2bc..3beacb05d8 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,5 +1,19 @@ 2016-12-31 Florian Weimer <fweimer@redhat.com> + [BZ #18784] + CVE-2015-5180 + * include/arpa/nameser_compat.h (T_QUERY_A_AND_AAAA): Rename from + T_UNSPEC. Adjust value. + * resolv/nss_dns/dns-host.c (_nss_dns_gethostbyname4_r): Use it. + * resolv/res_query.c (__libc_res_nquery): Likewise. + * resolv/res_mkquery.c (res_nmkquery): Check for out-of-range + QTYPEs. + * resolv/tst-resolv-qtypes.c: New file. + * resolv/Makefile (xtests): Add tst-resolv-qtypes. + (tst-resolv-qtypes): Link against libresolv and libpthread. + +2016-12-31 Florian Weimer <fweimer@redhat.com> + * elf/dl-tunables.h (__tunables_init): Fix unused attribute. 2016-12-31 Siddhesh Poyarekar <siddhesh@sourceware.org> diff --git a/NEWS b/NEWS index 7ebce44ca1..08b566d635 100644 --- a/NEWS +++ b/NEWS @@ -191,12 +191,18 @@ Version 2.25 Security related changes: - On ARM EABI (32-bit), generating a backtrace for execution contexts which +* On ARM EABI (32-bit), generating a backtrace for execution contexts which have been created with makecontext could fail to terminate due to a missing .cantunwind annotation. This has been observed to lead to a hang (denial of service) in some Go applications compiled with gccgo. Reported by Andreas Schwab. (CVE-2016-6323) +* The DNS stub resolver functions would crash due to a NULL pointer + dereference when processing a query with a valid DNS question type which + was used internally in the implementation. The stub resolver now uses a + question type which is outside the range of valid question type values. + (CVE-2015-5180) + The following bugs are resolved with this release: [The release manager will add the list generated by diff --git a/include/arpa/nameser_compat.h b/include/arpa/nameser_compat.h index 69280009b5..f7d0e043c6 100644 --- a/include/arpa/nameser_compat.h +++ b/include/arpa/nameser_compat.h @@ -3,9 +3,9 @@ # ifndef _ISOMAC -/* Picksome unused number to represent lookups of IPv4 and IPv6 (i.e., - T_A and T_AAAA). */ -#define T_UNSPEC 62321 +/* The number is outside the 16-bit RR type range and is used + internally by the implementation. */ +#define T_QUERY_A_AND_AAAA 439963904 # endif /* !_ISOMAC */ #endif diff --git a/resolv/Makefile b/resolv/Makefile index 1e9f56285c..10899959c5 100644 --- a/resolv/Makefile +++ b/resolv/Makefile @@ -49,6 +49,8 @@ tests += \ tst-resolv-network \ tst-resolv-search \ +# This test sends millions of packets and is rather slow. +xtests += tst-resolv-qtypes endif extra-libs-others = $(extra-libs) libresolv-routines := res_comp res_debug \ @@ -123,6 +125,7 @@ $(objpfx)tst-bug18665: $(objpfx)libresolv.so $(shared-thread-library) $(objpfx)tst-res_use_inet6: $(objpfx)libresolv.so $(shared-thread-library) $(objpfx)tst-resolv-basic: $(objpfx)libresolv.so $(shared-thread-library) $(objpfx)tst-resolv-network: $(objpfx)libresolv.so $(shared-thread-library) +$(objpfx)tst-resolv-qtypes: $(objpfx)libresolv.so $(shared-thread-library) $(objpfx)tst-resolv-search: $(objpfx)libresolv.so $(shared-thread-library) # This test case uses the deprecated RES_USE_INET6 resolver option. diff --git a/resolv/nss_dns/dns-host.c b/resolv/nss_dns/dns-host.c index 901e037451..d597faa8c4 100644 --- a/resolv/nss_dns/dns-host.c +++ b/resolv/nss_dns/dns-host.c @@ -324,7 +324,7 @@ _nss_dns_gethostbyname4_r (const char *name, struct gaih_addrtuple **pat, int olderr = errno; enum nss_status status; - int n = __libc_res_nsearch (&_res, name, C_IN, T_UNSPEC, + int n = __libc_res_nsearch (&_res, name, C_IN, T_QUERY_A_AND_AAAA, host_buffer.buf->buf, 2048, &host_buffer.ptr, &ans2p, &nans2p, &resplen2, &ans2p_malloced); if (n >= 0) diff --git a/resolv/res_mkquery.c b/resolv/res_mkquery.c index 12f9730199..d80b5318e5 100644 --- a/resolv/res_mkquery.c +++ b/resolv/res_mkquery.c @@ -103,6 +103,10 @@ res_nmkquery(res_state statp, int n; u_char *dnptrs[20], **dpp, **lastdnptr; + if (class < 0 || class > 65535 + || type < 0 || type > 65535) + return -1; + #ifdef DEBUG if (statp->options & RES_DEBUG) printf(";; res_nmkquery(%s, %s, %s, %s)\n", diff --git a/resolv/res_query.c b/resolv/res_query.c index 944d1a90f5..07dc6f6583 100644 --- a/resolv/res_query.c +++ b/resolv/res_query.c @@ -122,7 +122,7 @@ __libc_res_nquery(res_state statp, int n, use_malloc = 0; u_int oflags = statp->_flags; - size_t bufsize = (type == T_UNSPEC ? 2 : 1) * QUERYSIZE; + size_t bufsize = (type == T_QUERY_A_AND_AAAA ? 2 : 1) * QUERYSIZE; u_char *buf = alloca (bufsize); u_char *query1 = buf; int nquery1 = -1; @@ -137,7 +137,7 @@ __libc_res_nquery(res_state statp, printf(";; res_query(%s, %d, %d)\n", name, class, type); #endif - if (type == T_UNSPEC) + if (type == T_QUERY_A_AND_AAAA) { n = res_nmkquery(statp, QUERY, name, class, T_A, NULL, 0, NULL, query1, bufsize); @@ -190,7 +190,7 @@ __libc_res_nquery(res_state statp, if (__builtin_expect (n <= 0, 0) && !use_malloc) { /* Retry just in case res_nmkquery failed because of too short buffer. Shouldn't happen. */ - bufsize = (type == T_UNSPEC ? 2 : 1) * MAXPACKET; + bufsize = (type == T_QUERY_A_AND_AAAA ? 2 : 1) * MAXPACKET; buf = malloc (bufsize); if (buf != NULL) { query1 = buf; diff --git a/resolv/tst-resolv-qtypes.c b/resolv/tst-resolv-qtypes.c new file mode 100644 index 0000000000..b3e60c693b --- /dev/null +++ b/resolv/tst-resolv-qtypes.c @@ -0,0 +1,185 @@ +/* Exercise low-level query functions with different QTYPEs. + Copyright (C) 2016 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <resolv.h> +#include <string.h> +#include <support/check.h> +#include <support/check_nss.h> +#include <support/resolv_test.h> +#include <support/support.h> +#include <support/test-driver.h> +#include <support/xmemstream.h> + +/* If ture, the response function will send the actual response packet + over TCP instead of UDP. */ +static volatile bool force_tcp; + +/* Send back a fake resource record matching the QTYPE. */ +static void +response (const struct resolv_response_context *ctx, + struct resolv_response_builder *b, + const char *qname, uint16_t qclass, uint16_t qtype) +{ + if (force_tcp && ctx->tcp) + { + resolv_response_init (b, (struct resolv_response_flags) { .tc = 1 }); + resolv_response_add_question (b, qname, qclass, qtype); + return; + } + + resolv_response_init (b, (struct resolv_response_flags) { }); + resolv_response_add_question (b, qname, qclass, qtype); + resolv_response_section (b, ns_s_an); + resolv_response_open_record (b, qname, qclass, qtype, 0); + resolv_response_add_data (b, &qtype, sizeof (qtype)); + resolv_response_close_record (b); +} + +static const const char *domain = "www.example.com"; + +static int +wrap_res_query (int type, unsigned char *answer, int answer_length) +{ + return res_query (domain, C_IN, type, answer, answer_length); +} + +static int +wrap_res_search (int type, unsigned char *answer, int answer_length) +{ + return res_query (domain, C_IN, type, answer, answer_length); +} + +static int +wrap_res_querydomain (int type, unsigned char *answer, int answer_length) +{ + return res_querydomain ("www", "example.com", C_IN, type, + answer, answer_length); +} + +static int +wrap_res_send (int type, unsigned char *answer, int answer_length) +{ + unsigned char buf[512]; + int ret = res_mkquery (QUERY, domain, C_IN, type, + (const unsigned char *) "", 0, NULL, + buf, sizeof (buf)); + if (type < 0 || type >= 65536) + { + /* res_mkquery fails for out-of-range record types. */ + TEST_VERIFY_EXIT (ret == -1); + return -1; + } + TEST_VERIFY_EXIT (ret > 12); /* DNS header length. */ + return res_send (buf, ret, answer, answer_length); +} + +static int +wrap_res_nquery (int type, unsigned char *answer, int answer_length) +{ + return res_nquery (&_res, domain, C_IN, type, answer, answer_length); +} + +static int +wrap_res_nsearch (int type, unsigned char *answer, int answer_length) +{ + return res_nquery (&_res, domain, C_IN, type, answer, answer_length); +} + +static int +wrap_res_nquerydomain (int type, unsigned char *answer, int answer_length) +{ + return res_nquerydomain (&_res, "www", "example.com", C_IN, type, + answer, answer_length); +} + +static int +wrap_res_nsend (int type, unsigned char *answer, int answer_length) +{ + unsigned char buf[512]; + int ret = res_nmkquery (&_res, QUERY, domain, C_IN, type, + (const unsigned char *) "", 0, NULL, + buf, sizeof (buf)); + if (type < 0 || type >= 65536) + { + /* res_mkquery fails for out-of-range record types. */ + TEST_VERIFY_EXIT (ret == -1); + return -1; + } + TEST_VERIFY_EXIT (ret > 12); /* DNS header length. */ + return res_nsend (&_res, buf, ret, answer, answer_length); +} + +static void +test_function (const char *fname, + int (*func) (int type, + unsigned char *answer, int answer_length)) +{ + unsigned char buf[512]; + for (int tcp = 0; tcp < 2; ++tcp) + { + force_tcp = tcp; + for (unsigned int type = 1; type <= 65535; ++type) + { + if (test_verbose) + printf ("info: sending QTYPE %d with %s (tcp=%d)\n", + type, fname, tcp); + int ret = func (type, buf, sizeof (buf)); + if (ret != 47) + FAIL_EXIT1 ("%s tcp=%d qtype=%d return value %d", + fname,tcp, type, ret); + /* One question, one answer record. */ + TEST_VERIFY (memcmp (buf + 4, "\0\1\0\1\0\0\0\0", 8) == 0); + /* Question section. */ + static const char qname[] = "\3www\7example\3com"; + size_t qname_length = sizeof (qname); + TEST_VERIFY (memcmp (buf + 12, qname, qname_length) == 0); + /* RDATA part of answer. */ + uint16_t type16 = type; + TEST_VERIFY (memcmp (buf + ret - 2, &type16, sizeof (type16)) == 0); + } + } + + TEST_VERIFY (func (-1, buf, sizeof (buf) == -1)); + TEST_VERIFY (func (65536, buf, sizeof (buf) == -1)); +} + +static int +do_test (void) +{ + struct resolv_redirect_config config = + { + .response_callback = response, + }; + struct resolv_test *obj = resolv_test_start (config); + + test_function ("res_query", &wrap_res_query); + test_function ("res_search", &wrap_res_search); + test_function ("res_querydomain", &wrap_res_querydomain); + test_function ("res_send", &wrap_res_send); + + test_function ("res_nquery", &wrap_res_nquery); + test_function ("res_nsearch", &wrap_res_nsearch); + test_function ("res_nquerydomain", &wrap_res_nquerydomain); + test_function ("res_nsend", &wrap_res_nsend); + + resolv_test_end (obj); + return 0; +} + +#define TIMEOUT 300 +#include <support/test-driver.c> |