--- /dev/null
+From 4ab2ab03d4351914ee53248dc5aef4a8c88ff8b9 Mon Sep 17 00:00:00 2001
+From: Florian Weimer <fweimer@redhat.com>
+Date: Fri, 29 Apr 2016 10:35:34 +0200
+Subject: [PATCH] CVE-2016-3706: getaddrinfo: stack overflow in hostent
+ conversion [BZ #20010]
+
+When converting a struct hostent response to struct gaih_addrtuple, the
+gethosts macro (which is called from gaih_inet) used alloca, without
+malloc fallback for large responses. This commit changes this code to
+use calloc unconditionally.
+
+This commit also consolidated a second hostent-to-gaih_addrtuple
+conversion loop (in gaih_inet) to use the new conversion function.
+
+Upstream-Status: Backport
+CVE: CVE-2016-3706
+
+Signed-off-by: Armin Kuster <akuster@mvista.com>
+
+---
+ ChangeLog | 10 ++++
+ NEWS | 5 +-
+ sysdeps/posix/getaddrinfo.c | 130 +++++++++++++++++++++++---------------------
+ 3 files changed, 83 insertions(+), 62 deletions(-)
+
+Index: git/sysdeps/posix/getaddrinfo.c
+===================================================================
+--- git.orig/sysdeps/posix/getaddrinfo.c
++++ git/sysdeps/posix/getaddrinfo.c
+@@ -168,9 +168,58 @@ gaih_inet_serv (const char *servicename,
+ return 0;
+ }
+
++/* Convert struct hostent to a list of struct gaih_addrtuple objects.
++ h_name is not copied, and the struct hostent object must not be
++ deallocated prematurely. *RESULT must be NULL or a pointer to an
++ object allocated using malloc, which is freed. */
++static bool
++convert_hostent_to_gaih_addrtuple (const struct addrinfo *req,
++ int family,
++ struct hostent *h,
++ struct gaih_addrtuple **result)
++{
++ free (*result);
++ *result = NULL;
++
++ /* Count the number of addresses in h->h_addr_list. */
++ size_t count = 0;
++ for (char **p = h->h_addr_list; *p != NULL; ++p)
++ ++count;
++
++ /* Report no data if no addresses are available, or if the incoming
++ address size is larger than what we can store. */
++ if (count == 0 || h->h_length > sizeof (((struct gaih_addrtuple) {}).addr))
++ return true;
++
++ struct gaih_addrtuple *array = calloc (count, sizeof (*array));
++ if (array == NULL)
++ return false;
++
++ for (size_t i = 0; i < count; ++i)
++ {
++ if (family == AF_INET && req->ai_family == AF_INET6)
++ {
++ /* Perform address mapping. */
++ array[i].family = AF_INET6;
++ memcpy(array[i].addr + 3, h->h_addr_list[i], sizeof (uint32_t));
++ array[i].addr[2] = htonl (0xffff);
++ }
++ else
++ {
++ array[i].family = family;
++ memcpy (array[i].addr, h->h_addr_list[i], h->h_length);
++ }
++ array[i].next = array + i + 1;
++ }
++ array[0].name = h->h_name;
++ array[count - 1].next = NULL;
++
++ *result = array;
++ return true;
++}
++
+ #define gethosts(_family, _type) \
+ { \
+- int i; \
+ int herrno; \
+ struct hostent th; \
+ struct hostent *h; \
+@@ -219,36 +268,23 @@ gaih_inet_serv (const char *servicename,
+ } \
+ else if (h != NULL) \
+ { \
+- for (i = 0; h->h_addr_list[i]; i++) \
++ /* Make sure that addrmem can be freed. */ \
++ if (!malloc_addrmem) \
++ addrmem = NULL; \
++ if (!convert_hostent_to_gaih_addrtuple (req, _family,h, &addrmem)) \
+ { \
+- if (*pat == NULL) \
+- { \
+- *pat = __alloca (sizeof (struct gaih_addrtuple)); \
+- (*pat)->scopeid = 0; \
+- } \
+- uint32_t *addr = (*pat)->addr; \
+- (*pat)->next = NULL; \
+- (*pat)->name = i == 0 ? strdupa (h->h_name) : NULL; \
+- if (_family == AF_INET && req->ai_family == AF_INET6) \
+- { \
+- (*pat)->family = AF_INET6; \
+- addr[3] = *(uint32_t *) h->h_addr_list[i]; \
+- addr[2] = htonl (0xffff); \
+- addr[1] = 0; \
+- addr[0] = 0; \
+- } \
+- else \
+- { \
+- (*pat)->family = _family; \
+- memcpy (addr, h->h_addr_list[i], sizeof(_type)); \
+- } \
+- pat = &((*pat)->next); \
++ _res.options |= old_res_options & RES_USE_INET6; \
++ result = -EAI_SYSTEM; \
++ goto free_and_return; \
+ } \
++ *pat = addrmem; \
++ /* The conversion uses malloc unconditionally. */ \
++ malloc_addrmem = true; \
+ \
+ if (localcanon != NULL && canon == NULL) \
+ canon = strdupa (localcanon); \
+ \
+- if (_family == AF_INET6 && i > 0) \
++ if (_family == AF_INET6 && *pat != NULL) \
+ got_ipv6 = true; \
+ } \
+ }
+@@ -612,44 +648,16 @@ gaih_inet (const char *name, const struc
+ {
+ if (h != NULL)
+ {
+- int i;
+- /* We found data, count the number of addresses. */
+- for (i = 0; h->h_addr_list[i]; ++i)
+- ;
+- if (i > 0 && *pat != NULL)
+- --i;
+-
+- if (__libc_use_alloca (alloca_used
+- + i * sizeof (struct gaih_addrtuple)))
+- addrmem = alloca_account (i * sizeof (struct gaih_addrtuple),
+- alloca_used);
+- else
++ /* We found data, convert it. */
++ if (!convert_hostent_to_gaih_addrtuple
++ (req, AF_INET, h, &addrmem))
+ {
+- addrmem = malloc (i
+- * sizeof (struct gaih_addrtuple));
+- if (addrmem == NULL)
+- {
+- result = -EAI_MEMORY;
+- goto free_and_return;
+- }
+- malloc_addrmem = true;
+- }
+-
+- /* Now convert it into the list. */
+- struct gaih_addrtuple *addrfree = addrmem;
+- for (i = 0; h->h_addr_list[i]; ++i)
+- {
+- if (*pat == NULL)
+- {
+- *pat = addrfree++;
+- (*pat)->scopeid = 0;
+- }
+- (*pat)->next = NULL;
+- (*pat)->family = AF_INET;
+- memcpy ((*pat)->addr, h->h_addr_list[i],
+- h->h_length);
+- pat = &((*pat)->next);
++ result = -EAI_MEMORY;
++ goto free_and_return;
+ }
++ *pat = addrmem;
++ /* The conversion uses malloc unconditionally. */
++ malloc_addrmem = true;
+ }
+ }
+ else
+Index: git/NEWS
+===================================================================
+--- git.orig/NEWS
++++ git/NEWS
+@@ -2,6 +2,11 @@ GNU C Library NEWS -- history of user-vi
+ Copyright (C) 1992-2016 Free Software Foundation, Inc.
+ See the end for copying conditions.
+
++* Previously, getaddrinfo copied large amounts of address data to the stack,
++ even after the fix for CVE-2013-4458 has been applied, potentially
++ resulting in a stack overflow. getaddrinfo now uses a heap allocation
++ instead. Reported by Michael Petlan. (CVE-2016-3706)
++
+ Please send GNU C library bug reports via <http://sourceware.org/bugzilla/>
+ using `glibc' in the "product" field.
+ \f
+Index: git/ChangeLog
+===================================================================
+--- git.orig/ChangeLog
++++ git/ChangeLog
+@@ -1,3 +1,13 @@
++2016-04-29 Florian Weimer <fweimer@redhat.com>
++
++ [BZ #20010]
++ CVE-2016-3706
++ * sysdeps/posix/getaddrinfo.c
++ (convert_hostent_to_gaih_addrtuple): New function.
++ (gethosts): Call convert_hostent_to_gaih_addrtuple.
++ (gaih_inet): Use convert_hostent_to_gaih_addrtuple to convert
++ AF_INET data.
++
+ 2016-02-18 Adhemerval Zanella <adhemerval.zanella@linaro.org>
+
+ * configure: Regenerated.
