From 780684eb04298977bc411ebca1eadeeba4877833 Mon Sep 17 00:00:00 2001 From: "Maciej W. Rozycki" Date: Wed, 27 Jun 2018 21:12:16 +0100 Subject: [PATCH] nisplus: Correct pwent parsing issue and resulting build error [BZ #23266] Copy and null-terminate NIS+ password file UID and GID entries whose length is non-zero and are not terminated, in addition to empty ones, fixing a bug and a compilation issue causing an error with GCC 8: nss_nisplus/nisplus-parser.c: In function '_nss_nisplus_parse_pwent': nss_nisplus/nisplus-parser.c:90:7: error: 'strncpy' destination unchanged after copying no bytes [-Werror=stringop-truncation] strncpy (first_unused, numstr, len); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ nss_nisplus/nisplus-parser.c:106:7: error: 'strncpy' destination unchanged after copying no bytes [-Werror=stringop-truncation] strncpy (first_unused, numstr, len); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ introduced with commit ac05397075f6: commit ac05397075f621cfdbe1db527c96167a58b6d18e Author: Ulrich Drepper Date: Sun Apr 30 07:01:26 2006 +0000 * nis/nss_nisplus/nisplus-parser.c: Minor optimizations and cleanups. Avoid copying data if it can be used in the old place. (no mailing list reference available). Obviously regardless of the recently added compiler diagnostics causing a build error this code has been long non-functional, so I guess NIS+ servers have been supplying strings that are non-empty and have already been null-terminated. Which in turn made it unnecessary to make a null-terminated copy, masking this bug. [BZ #23266] * nis/nss_nisplus/nisplus-parser.c (_nss_nisplus_parse_pwent): Copy and null-terminate entries that are not terminated, in addition to empty ones. --- ChangeLog | 7 +++++++ nis/nss_nisplus/nisplus-parser.c | 4 ++-- 2 files changed, 9 insertions(+), 2 deletions(-) diff --git a/ChangeLog b/ChangeLog index 056d3c4a43..eb1c35feb5 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,10 @@ +2018-06-27 Maciej W. Rozycki + + [BZ #23266] + * nis/nss_nisplus/nisplus-parser.c (_nss_nisplus_parse_pwent): + Copy and null-terminate entries that are not terminated, in + addition to empty ones. + 2018-06-27 Florian Weimer [BZ #18023] diff --git a/nis/nss_nisplus/nisplus-parser.c b/nis/nss_nisplus/nisplus-parser.c index 8dc021e73d..d2b06334c2 100644 --- a/nis/nss_nisplus/nisplus-parser.c +++ b/nis/nss_nisplus/nisplus-parser.c @@ -82,7 +82,7 @@ _nss_nisplus_parse_pwent (nis_result *result, struct passwd *pw, char *numstr = NISOBJVAL (2, obj); len = NISOBJLEN (2, obj); - if (len == 0 && numstr[len - 1] != '\0') + if (len == 0 || numstr[len - 1] != '\0') { if (len >= room_left) goto no_more_room; @@ -98,7 +98,7 @@ _nss_nisplus_parse_pwent (nis_result *result, struct passwd *pw, numstr = NISOBJVAL (3, obj); len = NISOBJLEN (3, obj); - if (len == 0 && numstr[len - 1] != '\0') + if (len == 0 || numstr[len - 1] != '\0') { if (len >= room_left) goto no_more_room;