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[PATCH] Fix unbound stack use in NIS NSS module
- From: Andreas Schwab <schwab at suse dot de>
- To: libc-alpha at sourceware dot org
- Date: Mon, 12 May 2014 09:58:50 +0200
- Subject: [PATCH] Fix unbound stack use in NIS NSS module
- Authentication-results: sourceware.org; auth=none
yp_match needs to put its request in a single RPC packet, so don't
bother trying to support big items.
Andreas.
[BZ #16932]
* nis/nss_nis/nis-hosts.c (internal_gethostbyname2_r)
(_nss_nis_gethostbyname4_r): Return error if item length is larger
than maximum RPC packet size.
* nis/nss_nis/nis-initgroups.c (initgroups_netid): Likewise.
* nis/nss_nis/nis-network.c (_nss_nis_getnetbyname_r): Likewise.
* nis/nss_nis/nis-service.c (_nss_nis_getservbyname_r)
(_nss_nis_getservbyport_r): Likewise.
---
nis/nss_nis/nis-hosts.c | 14 ++++++++++++++
nis/nss_nis/nis-initgroups.c | 7 +++++++
nis/nss_nis/nis-network.c | 7 +++++++
nis/nss_nis/nis-service.c | 14 ++++++++++++++
4 files changed, 42 insertions(+)
diff --git a/nis/nss_nis/nis-hosts.c b/nis/nss_nis/nis-hosts.c
index 462176e..d6192b1 100644
--- a/nis/nss_nis/nis-hosts.c
+++ b/nis/nss_nis/nis-hosts.c
@@ -270,6 +270,13 @@ internal_gethostbyname2_r (const char *name, int af, struct hostent *host,
/* Convert name to lowercase. */
size_t namlen = strlen (name);
+ /* Limit name length to the maximum size of an RPC packet. */
+ if (namlen > UDPMSGSIZE)
+ {
+ *errnop = ERANGE;
+ return NSS_STATUS_UNAVAIL;
+ }
+
char name2[namlen + 1];
size_t i;
@@ -461,6 +468,13 @@ _nss_nis_gethostbyname4_r (const char *name, struct gaih_addrtuple **pat,
/* Convert name to lowercase. */
size_t namlen = strlen (name);
+ /* Limit name length to the maximum size of an RPC packet. */
+ if (namlen > UDPMSGSIZE)
+ {
+ *errnop = ERANGE;
+ return NSS_STATUS_UNAVAIL;
+ }
+
char name2[namlen + 1];
size_t i;
diff --git a/nis/nss_nis/nis-initgroups.c b/nis/nss_nis/nis-initgroups.c
index e8fcca1..9542fae 100644
--- a/nis/nss_nis/nis-initgroups.c
+++ b/nis/nss_nis/nis-initgroups.c
@@ -150,6 +150,13 @@ initgroups_netid (uid_t uid, gid_t group, long int *start, long int *size,
gid_t **groupsp, long int limit, int *errnop,
const char *domainname)
{
+ /* Limit domainname length to the maximum size of an RPC packet. */
+ if (strlen (domainname) > UDPMSGSIZE)
+ {
+ *errnop = ERANGE;
+ return NSS_STATUS_UNAVAIL;
+ }
+
/* Prepare the key. The form is "unix.UID@DOMAIN" with the UID and
DOMAIN field filled in appropriately. */
char key[sizeof ("unix.@") + sizeof (uid_t) * 3 + strlen (domainname)];
diff --git a/nis/nss_nis/nis-network.c b/nis/nss_nis/nis-network.c
index f28fbda..f1b72bc 100644
--- a/nis/nss_nis/nis-network.c
+++ b/nis/nss_nis/nis-network.c
@@ -179,6 +179,13 @@ _nss_nis_getnetbyname_r (const char *name, struct netent *net, char *buffer,
/* Convert name to lowercase. */
size_t namlen = strlen (name);
+ /* Limit name length to the maximum size of an RPC packet. */
+ if (namlen > UDPMSGSIZE)
+ {
+ *errnop = ERANGE;
+ return NSS_STATUS_UNAVAIL;
+ }
+
char name2[namlen + 1];
size_t i;
diff --git a/nis/nss_nis/nis-service.c b/nis/nss_nis/nis-service.c
index f9b4a86..44e4e13 100644
--- a/nis/nss_nis/nis-service.c
+++ b/nis/nss_nis/nis-service.c
@@ -271,6 +271,13 @@ _nss_nis_getservbyname_r (const char *name, const char *protocol,
/* If the protocol is given, we could try if our NIS server knows
about services.byservicename map. If yes, we only need one query. */
size_t keylen = strlen (name) + (protocol ? 1 + strlen (protocol) : 0);
+ /* Limit key length to the maximum size of an RPC packet. */
+ if (keylen > UDPMSGSIZE)
+ {
+ *errnop = ERANGE;
+ return NSS_STATUS_UNAVAIL;
+ }
+
char key[keylen + 1];
/* key is: "name/proto" */
@@ -355,6 +362,13 @@ _nss_nis_getservbyport_r (int port, const char *protocol,
Otherwise try first port/tcp, then port/udp and then fallback
to sequential scanning of services.byname. */
const char *proto = protocol != NULL ? protocol : "tcp";
+ /* Limit protocol name length to the maximum size of an RPC packet. */
+ if (strlen (proto) > UDPMSGSIZE)
+ {
+ *errnop = ERANGE;
+ return NSS_STATUS_UNAVAIL;
+ }
+
do
{
/* key is: "port/proto" */
--
1.9.2
--
Andreas Schwab, SUSE Labs, schwab@suse.de
GPG Key fingerprint = 0196 BAD8 1CE9 1970 F4BE 1748 E4D4 88E3 0EEA B9D7
"And now for something completely different."