diff --git a/glibc.changes b/glibc.changes index bada856..f78d8e6 100644 --- a/glibc.changes +++ b/glibc.changes @@ -1,3 +1,9 @@ +------------------------------------------------------------------- +Wed Sep 13 12:25:56 UTC 2023 - Andreas Schwab + +- no-aaaa-read-overflow.patch: Stack read overflow with large TCP + responses in no-aaaa mode (CVE-2023-4527, bsc#1215280, BZ #30842) + ------------------------------------------------------------------- Tue Sep 12 12:52:55 UTC 2023 - Andreas Schwab diff --git a/glibc.spec b/glibc.spec index d4b86c7..1f623a6 100644 --- a/glibc.spec +++ b/glibc.spec @@ -315,6 +315,8 @@ Patch1006: libio-io-vtables.patch Patch1007: call-init-proxy-objects.patch # PATCH-FIX-UPSTREAM elf: Always call destructors in reverse constructor order (BZ #30785) Patch1008: dtors-reverse-ctor-order.patch +# PATCH-FIX-UPSTREAM Stack read overflow with large TCP responses in no-aaaa mode (CVE-2023-4527, BZ #30842) +Patch1009: no-aaaa-read-overflow.patch ### # Patches awaiting upstream approval @@ -546,6 +548,7 @@ library in a cross compilation setting. %patch1006 -p1 %patch1007 -p1 %patch1008 -p1 +%patch1009 -p1 %endif %patch2000 -p1 diff --git a/no-aaaa-read-overflow.patch b/no-aaaa-read-overflow.patch new file mode 100644 index 0000000..65247872 --- /dev/null +++ b/no-aaaa-read-overflow.patch @@ -0,0 +1,193 @@ +From bd77dd7e73e3530203be1c52c8a29d08270cb25d Mon Sep 17 00:00:00 2001 +From: Florian Weimer +Date: Wed, 13 Sep 2023 14:10:56 +0200 +Subject: [PATCH] CVE-2023-4527: Stack read overflow with large TCP responses + in no-aaaa mode + +Without passing alt_dns_packet_buffer, __res_context_search can only +store 2048 bytes (what fits into dns_packet_buffer). However, +the function returns the total packet size, and the subsequent +DNS parsing code in _nss_dns_gethostbyname4_r reads beyond the end +of the stack-allocated buffer. + +Fixes commit f282cdbe7f436c75864e5640a4 ("resolv: Implement no-aaaa +stub resolver option") and bug 30842. +--- + NEWS | 6 +- + resolv/Makefile | 2 + + resolv/nss_dns/dns-host.c | 2 +- + resolv/tst-resolv-noaaaa-vc.c | 129 ++++++++++++++++++++++++++++++++++ + 4 files changed, 137 insertions(+), 2 deletions(-) + create mode 100644 resolv/tst-resolv-noaaaa-vc.c + +diff --git a/resolv/Makefile b/resolv/Makefile +index 054b1fa36c..2f99eb3862 100644 +--- a/resolv/Makefile ++++ b/resolv/Makefile +@@ -102,6 +102,7 @@ tests += \ + tst-resolv-invalid-cname \ + tst-resolv-network \ + tst-resolv-noaaaa \ ++ tst-resolv-noaaaa-vc \ + tst-resolv-nondecimal \ + tst-resolv-res_init-multi \ + tst-resolv-search \ +@@ -293,6 +294,7 @@ $(objpfx)tst-resolv-res_init-thread: $(objpfx)libresolv.so \ + $(objpfx)tst-resolv-invalid-cname: $(objpfx)libresolv.so \ + $(shared-thread-library) + $(objpfx)tst-resolv-noaaaa: $(objpfx)libresolv.so $(shared-thread-library) ++$(objpfx)tst-resolv-noaaaa-vc: $(objpfx)libresolv.so $(shared-thread-library) + $(objpfx)tst-resolv-nondecimal: $(objpfx)libresolv.so $(shared-thread-library) + $(objpfx)tst-resolv-qtypes: $(objpfx)libresolv.so $(shared-thread-library) + $(objpfx)tst-resolv-rotate: $(objpfx)libresolv.so $(shared-thread-library) +diff --git a/resolv/nss_dns/dns-host.c b/resolv/nss_dns/dns-host.c +index c8b77bbc35..119dc9f00f 100644 +--- a/resolv/nss_dns/dns-host.c ++++ b/resolv/nss_dns/dns-host.c +@@ -427,7 +427,7 @@ _nss_dns_gethostbyname4_r (const char *name, struct gaih_addrtuple **pat, + { + n = __res_context_search (ctx, name, C_IN, T_A, + dns_packet_buffer, sizeof (dns_packet_buffer), +- NULL, NULL, NULL, NULL, NULL); ++ &alt_dns_packet_buffer, NULL, NULL, NULL, NULL); + if (n >= 0) + status = gaih_getanswer_noaaaa (alt_dns_packet_buffer, n, + &abuf, pat, errnop, herrnop, ttlp); +diff --git a/resolv/tst-resolv-noaaaa-vc.c b/resolv/tst-resolv-noaaaa-vc.c +new file mode 100644 +index 0000000000..9f5aebd99f +--- /dev/null ++++ b/resolv/tst-resolv-noaaaa-vc.c +@@ -0,0 +1,129 @@ ++/* Test the RES_NOAAAA resolver option with a large response. ++ Copyright (C) 2022-2023 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 ++ . */ ++ ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++ ++/* Used to keep track of the number of queries. */ ++static volatile unsigned int queries; ++ ++/* If true, add a large TXT record at the start of the answer section. */ ++static volatile bool stuff_txt; ++ ++static void ++response (const struct resolv_response_context *ctx, ++ struct resolv_response_builder *b, ++ const char *qname, uint16_t qclass, uint16_t qtype) ++{ ++ /* If not using TCP, just force its use. */ ++ if (!ctx->tcp) ++ { ++ struct resolv_response_flags flags = {.tc = true}; ++ resolv_response_init (b, flags); ++ resolv_response_add_question (b, qname, qclass, qtype); ++ return; ++ } ++ ++ /* The test needs to send four queries, the first three are used to ++ grow the NSS buffer via the ERANGE handshake. */ ++ ++queries; ++ TEST_VERIFY (queries <= 4); ++ ++ /* AAAA queries are supposed to be disabled. */ ++ TEST_COMPARE (qtype, T_A); ++ TEST_COMPARE (qclass, C_IN); ++ TEST_COMPARE_STRING (qname, "example.com"); ++ ++ struct resolv_response_flags flags = {}; ++ resolv_response_init (b, flags); ++ resolv_response_add_question (b, qname, qclass, qtype); ++ ++ resolv_response_section (b, ns_s_an); ++ ++ if (stuff_txt) ++ { ++ resolv_response_open_record (b, qname, qclass, T_TXT, 60); ++ int zero = 0; ++ for (int i = 0; i <= 15000; ++i) ++ resolv_response_add_data (b, &zero, sizeof (zero)); ++ resolv_response_close_record (b); ++ } ++ ++ for (int i = 0; i < 200; ++i) ++ { ++ resolv_response_open_record (b, qname, qclass, qtype, 60); ++ char ipv4[4] = {192, 0, 2, i + 1}; ++ resolv_response_add_data (b, &ipv4, sizeof (ipv4)); ++ resolv_response_close_record (b); ++ } ++} ++ ++static int ++do_test (void) ++{ ++ struct resolv_test *obj = resolv_test_start ++ ((struct resolv_redirect_config) ++ { ++ .response_callback = response ++ }); ++ ++ _res.options |= RES_NOAAAA; ++ ++ for (int do_stuff_txt = 0; do_stuff_txt < 2; ++do_stuff_txt) ++ { ++ queries = 0; ++ stuff_txt = do_stuff_txt; ++ ++ struct addrinfo *ai = NULL; ++ int ret; ++ ret = getaddrinfo ("example.com", "80", ++ &(struct addrinfo) ++ { ++ .ai_family = AF_UNSPEC, ++ .ai_socktype = SOCK_STREAM, ++ }, &ai); ++ ++ char *expected_result; ++ { ++ struct xmemstream mem; ++ xopen_memstream (&mem); ++ for (int i = 0; i < 200; ++i) ++ fprintf (mem.out, "address: STREAM/TCP 192.0.2.%d 80\n", i + 1); ++ xfclose_memstream (&mem); ++ expected_result = mem.buffer; ++ } ++ ++ check_addrinfo ("example.com", ai, ret, expected_result); ++ ++ free (expected_result); ++ freeaddrinfo (ai); ++ } ++ ++ resolv_test_end (obj); ++ return 0; ++} ++ ++#include +-- +2.42.0 +