From: Mark Wielaard <mjw@redhat.com>
Date: Sat, 30 May 2015 21:43:11 +0000 (+0200)
Subject: libelf: Don't call mempcpy with possible NULL d_buf.
X-Git-Tag: elfutils-0.162~25
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=b4ad3c4b81c57b36d9837dc81523cfa7950f30a7;p=thirdparty%2Felfutils.git

libelf: Don't call mempcpy with possible NULL d_buf.

When d_size is zero d_buf might be NULL. last_position doesn't need to be
updated in that case.

Signed-off-by: Mark Wielaard <mjw@redhat.com>
---

diff --git a/libelf/ChangeLog b/libelf/ChangeLog
index 5f66135f1..b8c20cc68 100644
--- a/libelf/ChangeLog
+++ b/libelf/ChangeLog
@@ -1,3 +1,8 @@
+2015-05-30  Mark Wielaard  <mjw@redhat.com>
+
+	* elf32_updatefile.c (updatemmap): Only call mempcpy and update
+	last_position when d_size is non-zero.
+
 2015-05-17  Mark Wielaard  <mjw@redhat.com>
 
 	* elf32_updatefile.c (updatefile): Allocate shdr_data and scns
diff --git a/libelf/elf32_updatefile.c b/libelf/elf32_updatefile.c
index e90ad47d4..913c3e462 100644
--- a/libelf/elf32_updatefile.c
+++ b/libelf/elf32_updatefile.c
@@ -367,7 +367,7 @@ __elfw2(LIBELFBITS,updatemmap) (Elf *elf, int change_bo, size_t shnum)
 
 			last_position += dl->data.d.d_size;
 		      }
-		    else
+		    else if (dl->data.d.d_size != 0)
 		      last_position = mempcpy (last_position,
 					       dl->data.d.d_buf,
 					       dl->data.d.d_size);