From 883dceebc8f11921a9890211a4e202e5be17562f Mon Sep 17 00:00:00 2001
From: Florian Weimer <fweimer@redhat.com>
Date: Tue, 29 Mar 2016 12:57:56 +0200
Subject: [PATCH 51/65] CVE-2016-3075: Stack overflow in
_nss_dns_getnetbyname_r [BZ #19879]
The defensive copy is not needed because the name may not alias the
output buffer.
(cherry picked from commit 317b199b4aff8cfa27f2302ab404d2bb5032b9a4)
---
ChangeLog | 7 +++++++
resolv/nss_dns/dns-network.c | 5 +----
2 files changed, 8 insertions(+), 4 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index 3e0d69b..c262784 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2016-04-01 Florian Weimer <fweimer@redhat.com>
+
+ [BZ #19879]
+ CVE-2016-3075
+ * resolv/nss_dns/dns-network.c (_nss_dns_getnetbyname_r): Do not
+ copy name.
+
2016-03-25 Florian Weimer <fweimer@redhat.com>
[BZ #19791]
diff --git a/resolv/nss_dns/dns-network.c b/resolv/nss_dns/dns-network.c
index 00f4490..89f8783 100644
--- a/resolv/nss_dns/dns-network.c
+++ b/resolv/nss_dns/dns-network.c
@@ -118,17 +118,14 @@ _nss_dns_getnetbyname_r (const char *name, struct netent *result,
} net_buffer;
querybuf *orig_net_buffer;
int anslen;
- char *qbuf;
enum nss_status status;
if (__res_maybe_init (&_res, 0) == -1)
return NSS_STATUS_UNAVAIL;
- qbuf = strdupa (name);
-
net_buffer.buf = orig_net_buffer = (querybuf *) alloca (1024);
- anslen = __libc_res_nsearch (&_res, qbuf, C_IN, T_PTR, net_buffer.buf->buf,
+ anslen = __libc_res_nsearch (&_res, name, C_IN, T_PTR, net_buffer.buf->buf,
1024, &net_buffer.ptr, NULL, NULL, NULL, NULL);
if (anslen < 0)
{
--
2.7.4
