Author: cjg Date: Sun Jul 27 04:18:13 2014 New Revision: 2957 Log: Just added a patch for nfs-utils that fixes run-time segfaults when using gcc 4.9.x.
Added: trunk/nfs-utils/nfs-utils-1.3.0-gcc-4.9-1.patch Added: trunk/nfs-utils/nfs-utils-1.3.0-gcc-4.9-1.patch ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ trunk/nfs-utils/nfs-utils-1.3.0-gcc-4.9-1.patch Sun Jul 27 04:18:13 2014 (r2957) @@ -0,0 +1,70 @@ +Submitted By: Christopher Gregory <cjg at linuxfromscratch dot org> +Date: 2010-09-03 +Initial Package Version: 1.3.0 +Upstream Status: unknown +Origin: found on gentoo portage message board. +Description: Fix add_name segfault with gcc 4.9.x +Comment: + +From 25e83c2270b2d2966c992885faed0b79be09f474 Mon Sep 17 00:00:00 2001 +From: Jeff Layton <[email protected]> +Date: Thu, 1 May 2014 11:15:16 -0400 +Subject: [PATCH [nfs-utils]] mountd: fix segfault in add_name with newer gcc + compilers + +I hit a segfault in add_name with a mountd built with gcc-4.9.0. Some +NULL pointer checks got reordered such that a pointer was dereferenced +before checking to see whether it was NULL. The problem was due to +nfs-utils relying on undefined behavior, which tricked gcc into assuming +that the pointer would never be NULL. + +At first I assumed that this was a compiler bug, but Jakub Jelinek and +Jeff Law pointed out: + +"If old is NULL, then: + + strncpy(new, old, cp-old); + +is undefined behavior (even when cp == old == NULL in that case), +therefore gcc assumes that old is never NULL, as otherwise it would be +invalid. + +Just guard + strncpy(new, old, cp-old); + new[cp-old] = 0; +with if (old) { ... }." + +This patch does that. If old is NULL though, then we still need to +ensure that new is NULL terminated, lest the subsequent strcats walk off +the end of it. + +Cc: Jeff Law <[email protected]> +Cc: Jakub Jelinek <[email protected]> +Signed-off-by: Jeff Layton <[email protected]> +Signed-off-by: Steve Dickson <[email protected]> +--- + support/export/client.c | 8 ++++++-- + 1 file changed, 6 insertions(+), 2 deletions(-) + +diff --git a/support/export/client.c b/support/export/client.c +index dbf47b9..f85e11c 100644 +--- a/support/export/client.c ++++ b/support/export/client.c +@@ -482,8 +482,12 @@ add_name(char *old, const char *add) + else + cp = cp + strlen(cp); + } +- strncpy(new, old, cp-old); +- new[cp-old] = 0; ++ if (old) { ++ strncpy(new, old, cp-old); ++ new[cp-old] = 0; ++ } else { ++ new[0] = 0; ++ } + if (cp != old && !*cp) + strcat(new, ","); + strcat(new, add); +-- +2.0.0 + -- http://lists.linuxfromscratch.org/listinfo/patches FAQ: http://www.linuxfromscratch.org/blfs/faq.html Unsubscribe: See the above information page
