diff options
Diffstat (limited to 'patches/glibc-2.23/0002-CVE-2016-3706-getaddrinfo-stack-overflow-in-hostent-.patch')
| -rw-r--r-- | patches/glibc-2.23/0002-CVE-2016-3706-getaddrinfo-stack-overflow-in-hostent-.patch | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/patches/glibc-2.23/0002-CVE-2016-3706-getaddrinfo-stack-overflow-in-hostent-.patch b/patches/glibc-2.23/0002-CVE-2016-3706-getaddrinfo-stack-overflow-in-hostent-.patch new file mode 100644 index 0000000..20b227c --- /dev/null +++ b/patches/glibc-2.23/0002-CVE-2016-3706-getaddrinfo-stack-overflow-in-hostent-.patch @@ -0,0 +1,181 @@ +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. +--- + sysdeps/posix/getaddrinfo.c | 130 +++++++++++++++++++++++--------------------- + 1 file changed, 69 insertions(+), 61 deletions(-) + +diff --git a/sysdeps/posix/getaddrinfo.c b/sysdeps/posix/getaddrinfo.c +index 1ef3f20d987b..fed2d3bf130b 100644 +--- a/sysdeps/posix/getaddrinfo.c ++++ b/sysdeps/posix/getaddrinfo.c +@@ -168,9 +168,58 @@ gaih_inet_serv (const char *servicename, const struct gaih_typeproto *tp, + 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, const struct gaih_typeproto *tp, + } \ + 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 struct gaih_service *service, + { + 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 +- { +- 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) ++ /* We found data, convert it. */ ++ if (!convert_hostent_to_gaih_addrtuple ++ (req, AF_INET, h, &addrmem)) + { +- 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 |