nfs-utils: fix for segfault in add_name

Signed-off-by: Tudor Florea <tudor.florea@enea.com>
Signed-off-by: Adrian Calianu <adrian.calianu@enea.com>

2 files changed, 64 insertions, 0 deletions

diff --git a/recipes-connectivity/nfs-utils/nfs-utils/fix-segfault-in-add_name.patch b/recipes-connectivity/nfs-utils/nfs-utils/fix-segfault-in-add_name.patch
new file mode 100644
index 0000000..4ebf2dc
--- /dev/null
+++ b/recipes-connectivity/nfs-utils/nfs-utils/fix-segfault-in-add_name.patch
@@ -0,0 +1,59 @@
+commit 25e83c2270b2d2966c992885faed0b79be09f474
+Author: Jeff Layton <jlayton@poochiereds.net>
+Date:   Thu May 1 11:15:16 2014 -0400
+
+    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 <law@redhat.com>
+    Cc: Jakub Jelinek <jakub@redhat.com>
+    Signed-off-by: Jeff Layton <jlayton@poochiereds.net>
+    Signed-off-by: Steve Dickson <steved@redhat.com>
+
+    Upstream-Status:Backport
+    Signed-off-by: Tudor Florea <tudor.florea@enea.com>
+
+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);
diff --git a/recipes-connectivity/nfs-utils/nfs-utils_1.3.0.bbappend b/recipes-connectivity/nfs-utils/nfs-utils_1.3.0.bbappend
new file mode 100644
index 0000000..7c9faf0
--- /dev/null
+++ b/recipes-connectivity/nfs-utils/nfs-utils_1.3.0.bbappend
@@ -0,0 +1,5 @@
+FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:"
+
+SRC_URI += " \
+           file://fix-segfault-in-add_name.patch \
+"