elfutils: check data_list.data.d.d_buf before free it

[YOCTO #12791]

The one which actually saves the data is data_list.data.d.d_buf, so check it
before free rawdata_base.

This can fix a segmentation fault when prelink libqb_1.0.3:
prelink: /usr/lib/libqb.so.0.18.2: Symbol section index outside of section numbers

The segmentation fault happens when prelink call elf_end().

Fixed:
MACHINE="qemux86-64"
IMAGE_INSTALL_append = " libqb" #libqp is from meta-openembedded
$ bitbake core-image-minimal
Segmention fault

(From OE-Core rev: 560154e8525dce4beb8199ffc0d7c964da9d665a)

Signed-off-by: Robert Yang <liezhi.yang@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 39 insertions, 0 deletions

diff --git a/meta/recipes-devtools/elfutils/files/0001-libelf-elf_end.c-check-data_list.data.d.d_buf-before.patch b/meta/recipes-devtools/elfutils/files/0001-libelf-elf_end.c-check-data_list.data.d.d_buf-before.patch
new file mode 100644
index 0000000000..8b03c0ea6b
--- /dev/null
+++ b/meta/recipes-devtools/elfutils/files/0001-libelf-elf_end.c-check-data_list.data.d.d_buf-before.patch
@@ -0,0 +1,39 @@
+From d68822e93c57c3fbb77b93eada5986d2240157c2 Mon Sep 17 00:00:00 2001
+From: Robert Yang <liezhi.yang@windriver.com>
+Date: Thu, 16 Aug 2018 09:58:26 +0800
+Subject: [PATCH] libelf/elf_end.c: check data_list.data.d.d_buf before free it
+
+The one which actually saves the data is data_list.data.d.d_buf, so check it
+before free rawdata_base.
+
+This can fix a segmentation fault when prelink libqb_1.0.3:
+prelink: /usr/lib/libqb.so.0.18.2: Symbol section index outside of section numbers
+
+The segmentation fault happens when prelink call elf_end().
+
+Upstream-Status: Submitted [https://sourceware.org/ml/elfutils-devel/2018-q3/msg00065.html]
+
+Signed-off-by: Robert Yang <liezhi.yang@windriver.com>
+---
+ libelf/elf_end.c | 3 ++-
+ 1 file changed, 2 insertions(+), 1 deletion(-)
+
+diff --git a/libelf/elf_end.c b/libelf/elf_end.c
+index 160f0b8..5388e80 100644
+--- a/libelf/elf_end.c
++++ b/libelf/elf_end.c
+@@ -165,9 +165,10 @@ elf_end (Elf *elf)
+ 
+                /* The section data is allocated if we couldn't mmap
+                   the file.  Or if we had to decompress.  */
+-               if (elf->map_address == NULL
++               if ((elf->map_address == NULL
+                    || scn->rawdata_base == scn->zdata_base
+                    || (scn->flags & ELF_F_MALLOCED) != 0)
++                   && (scn->data_list.data.d.d_buf != NULL))
+                  free (scn->rawdata_base);
+ 
+                /* Free the list of data buffers for the section.
+-- 
+2.7.4
+