From 2d3253fbf4b9525c01cda64176c3d7470b50efaa Mon Sep 17 00:00:00 2001 From: Enno Boland Date: Fri, 5 Sep 2014 19:49:56 +0200 Subject: [PATCH] nfs-utils: fix segfault on mount. --- ...ult-in-add_name-with-newer-gcc-compi.patch | 63 +++++++++++++++++++ 1 file changed, 63 insertions(+) create mode 100644 srcpkgs/nfs-utils/patches/22-mountd-fix-segfault-in-add_name-with-newer-gcc-compi.patch diff --git a/srcpkgs/nfs-utils/patches/22-mountd-fix-segfault-in-add_name-with-newer-gcc-compi.patch b/srcpkgs/nfs-utils/patches/22-mountd-fix-segfault-in-add_name-with-newer-gcc-compi.patch new file mode 100644 index 00000000000..c8354042280 --- /dev/null +++ b/srcpkgs/nfs-utils/patches/22-mountd-fix-segfault-in-add_name-with-newer-gcc-compi.patch @@ -0,0 +1,63 @@ +From 8b03fdbfb0dd8e0147aa61ff30b8311235caf5f3 Mon Sep 17 00:00:00 2001 +From: Jeff Layton +Date: Thu, 1 May 2014 11:15:16 -0400 +Subject: [PATCH] mountd: fix segfault in add_name with newer gcc compilers +Bug-Debian: http://bugs.debian.org/757835 +Bug-Ubuntu: https://bugs.launchpad.net/ubuntu/+bug/1355829 + +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 +Cc: Jakub Jelinek +Signed-off-by: Jeff Layton +Signed-off-by: Steve Dickson +--- + support/export/client.c | 8 ++++++-- + 1 file changed, 6 insertions(+), 2 deletions(-) + +diff --git support/export/client.c support/export/client.c +index ba2db8f..e749cac 100644 +--- support/export/client.c ++++ 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); +-- +2.1.0.rc1 +