From f40cbd43acdb1fefef4fa53a6034296d83cbff7d 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/msg00085.html]

Signed-off-by: Robert Yang <liezhi.yang@windriver.com>

---
 libelf/elf_end.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/libelf/elf_end.c b/libelf/elf_end.c
index 160f0b8..5280a70 100644
--- a/libelf/elf_end.c
+++ b/libelf/elf_end.c
@@ -160,14 +160,16 @@ elf_end (Elf *elf)
 		   architecture doesn't require overly stringent
 		   alignment the raw data buffer is the same as the
 		   one used for presenting to the caller.  */
-		if (scn->data_base != scn->rawdata_base)
+		if ((scn->data_base != scn->rawdata_base)
+		    && (scn->data_list.data.d.d_buf != NULL))
 		  free (scn->data_base);
 
 		/* 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.