The following was taken from Ubuntu 12.04 eglibc-2.15 source and the Makefile patch was slightly modified to work against eglibc 2.12. From: Andreas Schwab Date: Mon, 21 Jan 2013 16:41:28 +0000 (+0100) Subject: Fix parsing of numeric hosts in gethostbyname_r X-Git-Tag: glibc-2.18~221 X-Git-Url: https://sourceware.org/git/?p=glibc.git;a=commitdiff_plain;h=d5dd6189d506068ed11c8bfa1e1e9bffde04decd Fix parsing of numeric hosts in gethostbyname_r 2013-05-21 Andreas Schwab [BZ #15014] * nss/getXXbyYY_r.c (INTERNAL (REENTRANT_NAME)) [HANDLE_DIGITS_DOTS]: Set any_service when digits-dots parsing was successful. * nss/digits_dots.c (__nss_hostname_digits_dots): Remove redundant variable declarations and reallocation of buffer when parsing as IPv6 address. Always set NSS status when called from reentrant functions. Use NETDB_INTERNAL instead of TRY_AGAIN when buffer too small. Correct computation of needed size. * nss/Makefile (tests): Add test-digits-dots. * nss/test-digits-dots.c: New test. CVE-2015-0235 (Ubuntu note: patch differs from upstream commit in that it drops the changelog and NEWS entries as well as the whitespace only change to nss/getXXbyYY_r.c to reduce patch conflicts. --sbeattie) --- nss/Makefile | 2 - nss/digits_dots.c | 73 +++++++++++++------------------------------------ nss/getXXbyYY_r.c | 3 ++ nss/test-digits-dots.c | 38 +++++++++++++++++++++++++ 4 files changed, 62 insertions(+), 54 deletions(-) Index: libc/nss/digits_dots.c =================================================================== --- libc.orig/nss/digits_dots.c 2010-11-16 12:47:37.000000000 -0600 +++ libc/nss/digits_dots.c 2015-01-28 14:09:33.942597967 -0600 @@ -47,7 +47,10 @@ { if (h_errnop) *h_errnop = NETDB_INTERNAL; - *result = NULL; + if (buffer_size == NULL) + *status = NSS_STATUS_TRYAGAIN; + else + *result = NULL; return -1; } @@ -84,14 +87,16 @@ } size_needed = (sizeof (*host_addr) - + sizeof (*h_addr_ptrs) + strlen (name) + 1); + + sizeof (*h_addr_ptrs) + + sizeof (*h_alias_ptr) + strlen (name) + 1); if (buffer_size == NULL) { if (buflen < size_needed) { + *status = NSS_STATUS_TRYAGAIN; if (h_errnop != NULL) - *h_errnop = TRY_AGAIN; + *h_errnop = NETDB_INTERNAL; __set_errno (ERANGE); goto done; } @@ -110,7 +115,7 @@ *buffer_size = 0; __set_errno (save); if (h_errnop != NULL) - *h_errnop = TRY_AGAIN; + *h_errnop = NETDB_INTERNAL; *result = NULL; goto done; } @@ -150,7 +155,9 @@ if (! ok) { *h_errnop = HOST_NOT_FOUND; - if (buffer_size) + if (buffer_size == NULL) + *status = NSS_STATUS_NOTFOUND; + else *result = NULL; goto done; } @@ -191,7 +198,7 @@ if (buffer_size == NULL) *status = NSS_STATUS_SUCCESS; else - *result = resbuf; + *result = resbuf; goto done; } @@ -202,15 +209,6 @@ if ((isxdigit (name[0]) && strchr (name, ':') != NULL) || name[0] == ':') { - const char *cp; - char *hostname; - typedef unsigned char host_addr_t[16]; - host_addr_t *host_addr; - typedef char *host_addr_list_t[2]; - host_addr_list_t *h_addr_ptrs; - size_t size_needed; - int addr_size; - switch (af) { default: @@ -226,7 +224,10 @@ /* This is not possible. We cannot represent an IPv6 address in an `struct in_addr' variable. */ *h_errnop = HOST_NOT_FOUND; - *result = NULL; + if (buffer_size == NULL) + *status = NSS_STATUS_NOTFOUND; + else + *result = NULL; goto done; case AF_INET6: @@ -234,42 +235,6 @@ break; } - size_needed = (sizeof (*host_addr) - + sizeof (*h_addr_ptrs) + strlen (name) + 1); - - if (buffer_size == NULL && buflen < size_needed) - { - if (h_errnop != NULL) - *h_errnop = TRY_AGAIN; - __set_errno (ERANGE); - goto done; - } - else if (buffer_size != NULL && *buffer_size < size_needed) - { - char *new_buf; - *buffer_size = size_needed; - new_buf = realloc (*buffer, *buffer_size); - - if (new_buf == NULL) - { - save = errno; - free (*buffer); - __set_errno (save); - *buffer = NULL; - *buffer_size = 0; - *result = NULL; - goto done; - } - *buffer = new_buf; - } - - memset (*buffer, '\0', size_needed); - - host_addr = (host_addr_t *) *buffer; - h_addr_ptrs = (host_addr_list_t *) - ((char *) host_addr + sizeof (*host_addr)); - hostname = (char *) h_addr_ptrs + sizeof (*h_addr_ptrs); - for (cp = name;; ++cp) { if (!*cp) @@ -282,7 +247,9 @@ if (inet_pton (AF_INET6, name, host_addr) <= 0) { *h_errnop = HOST_NOT_FOUND; - if (buffer_size) + if (buffer_size == NULL) + *status = NSS_STATUS_NOTFOUND; + else *result = NULL; goto done; } Index: libc/nss/getXXbyYY_r.c =================================================================== --- libc.orig/nss/getXXbyYY_r.c 2010-11-16 12:47:37.000000000 -0600 +++ libc/nss/getXXbyYY_r.c 2015-01-28 14:09:33.942597967 -0600 @@ -178,6 +178,9 @@ case -1: return errno; case 1: +#ifdef NEED_H_ERRNO + any_service = true; +#endif goto done; } #endif Index: libc/nss/test-digits-dots.c =================================================================== --- /dev/null 1970-01-01 00:00:00.000000000 +0000 +++ libc/nss/test-digits-dots.c 2015-01-28 14:09:33.978597382 -0600 @@ -0,0 +1,38 @@ +/* Copyright (C) 2013 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 + . */ + +/* Testcase for BZ #15014 */ + +#include +#include +#include + +static int +do_test (void) +{ + char buf[32]; + struct hostent *result = NULL; + struct hostent ret; + int h_err = 0; + int err; + + err = gethostbyname_r ("1.2.3.4", &ret, buf, sizeof (buf), &result, &h_err); + return err == ERANGE && h_err == NETDB_INTERNAL ? EXIT_SUCCESS : EXIT_FAILURE; +} + +#define TEST_FUNCTION do_test () +#include "../test-skeleton.c" Index: libc/nss/Makefile =================================================================== --- libc.orig/nss/Makefile 2015-01-28 14:09:26.000000000 -0600 +++ libc/nss/Makefile 2015-01-28 14:10:37.181572603 -0600 @@ -46,6 +46,7 @@ others := getent install-bin := getent +tests = test-digits-dots tests-$(OPTION_EGLIBC_INET) += test-netdb xtests-$(OPTION_EGLIBC_INET) += bug-erange