From 317b199b4aff8cfa27f2302ab404d2bb5032b9a4 Mon Sep 17 00:00:00 2001 From: Florian Weimer Date: Tue, 29 Mar 2016 12:57:56 +0200 Subject: [PATCH] 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. --- ChangeLog | 7 +++++++ resolv/nss_dns/dns-network.c | 5 +---- 2 files changed, 8 insertions(+), 4 deletions(-) diff --git a/ChangeLog b/ChangeLog index ce6f8a2204..b620bbfcfa 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,10 @@ +2016-03-29 Florian Weimer + + [BZ #19879] + CVE-2016-3075 + * resolv/nss_dns/dns-network.c (_nss_dns_getnetbyname_r): Do not + copy name. + 2016-03-29 Florian Weimer [BZ #19837] diff --git a/resolv/nss_dns/dns-network.c b/resolv/nss_dns/dns-network.c index 2eb2f67e66..8f301a706b 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) {