From 916ef0f69613613e11123657bff127bd26104630 Mon Sep 17 00:00:00 2001 From: Florian Weimer Date: Tue, 29 Mar 2016 12:57:56 +0200 Subject: 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) (cherry picked from commit f5b3338d70a7a2c626331ac4589b6deb2f610432) --- ChangeLog | 7 +++++++ NEWS | 4 ++++ resolv/nss_dns/dns-network.c | 5 +---- 3 files changed, 12 insertions(+), 4 deletions(-) diff --git a/ChangeLog b/ChangeLog index 3652d5f029..4b5cd019e1 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,10 @@ +2016-05-24 Florian Weimer + + [BZ #19879] + CVE-2016-3075 + * resolv/nss_dns/dns-network.c (_nss_dns_getnetbyname_r): Do not + copy name. + 2016-05-24 Paul Pluzhnikov [BZ #17905] diff --git a/NEWS b/NEWS index e6a520774a..dc8679f8ca 100644 --- a/NEWS +++ b/NEWS @@ -17,6 +17,10 @@ Version 2.20.1 called with the GLOB_ALTDIRFUNC flag and encountered a long file name. Reported by Alexander Cherepanov. (CVE-2016-1234) +* An unnecessary stack copy in _nss_dns_getnetbyname_r was removed. It + could result in a stack overflow when getnetbyname was called with an + overly long name. (CVE-2016-3075) + * Previously, getaddrinfo copied large amounts of address data to the stack, even after the fix for CVE-2013-4458 has been applied, potentially resulting in a stack overflow. getaddrinfo now uses a heap allocation diff --git a/resolv/nss_dns/dns-network.c b/resolv/nss_dns/dns-network.c index 08cf0a6462..335604adc2 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) { -- cgit v1.2.1