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[PATCH] CVE-2016-3075: Stack overflow in _nss_dns_getnetbyname_r [BZ #19879]
- From: Florian Weimer <fweimer at redhat dot com>
- To: GNU C Library <libc-alpha at sourceware dot org>
- Date: Tue, 29 Mar 2016 13:01:17 +0200
- Subject: [PATCH] CVE-2016-3075: Stack overflow in _nss_dns_getnetbyname_r [BZ #19879]
- Authentication-results: sourceware.org; auth=none
This is a minor security issue in nss_dns, triggered by a very long name
passed to getnetbyname.
The defensive copy is not needed because the name may not alias the
output buffer.
Florian
2016-03-29 Florian Weimer <fweimer@redhat.com>
[BZ #19879]
CVE-2016-3075
* resolv/nss_dns/dns-network.c (_nss_dns_getnetbyname_r): Do not
copy name.
diff --git a/resolv/nss_dns/dns-network.c b/resolv/nss_dns/dns-network.c
index 2eb2f67..8f301a7 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)
{