From: Mark Wielaard <mark@klomp.org>
Date: Thu, 31 May 2018 11:01:39 +0000 (+0200)
Subject: libdw: Don't crash on invalid die in dwarf_dieoffset.
X-Git-Tag: elfutils-0.171~8
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=aa02fb9028abcadaa18440b86b1ed085e029956c;p=thirdparty%2Felfutils.git

libdw: Don't crash on invalid die in dwarf_dieoffset.

Add explicit test in get-units-invalid for dwarf_cuoffset and
dwarf_dieoffset. Make sure dwarf_dieoffset returns (Dwarf_Off) -1
on failure.

Signed-off-by: Mark Wielaard <mark@klomp.org>
---

diff --git a/libdw/ChangeLog b/libdw/ChangeLog
index 5a33d9c12..38b45badd 100644
--- a/libdw/ChangeLog
+++ b/libdw/ChangeLog
@@ -1,3 +1,8 @@
+2018-05-31  Mark Wielaard  <mark@klomp.org>
+
+	* dwarf_dieoffset.c: Check die->cu != NULL. Return -1, not ~0ul
+	on failure.
+
 2018-05-29  Mark Wielaard  <mark@klomp.org>
 
 	* dwarf_cuoffset.c (dwarf_cuoffset): Check die->cu is not NULL.
diff --git a/libdw/dwarf_dieoffset.c b/libdw/dwarf_dieoffset.c
index 8028f6dd2..3a8e2cb69 100644
--- a/libdw/dwarf_dieoffset.c
+++ b/libdw/dwarf_dieoffset.c
@@ -38,8 +38,8 @@
 Dwarf_Off
 dwarf_dieoffset (Dwarf_Die *die)
 {
-  return (die == NULL
-	  ? ~0ul
+  return ((die == NULL || die->cu == NULL)
+	  ? (Dwarf_Off) -1
 	  : (Dwarf_Off) (die->addr - die->cu->startp + die->cu->start));
 }
 INTDEF(dwarf_dieoffset)
diff --git a/src/ChangeLog b/src/ChangeLog
index f424fb7f6..03ed5aabd 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,7 @@
+2018-05-31  Mark Wielaard  <mark@klomp.org>
+
+	* readelf.c (print_debug_units): Check offset against -1 not ~0ul.
+
 2018-05-29  Mark Wielaard  <mark@klomp.org>
 
 	* readelf.c (print_debug_loc_section): Handle GNU DebugFission list
diff --git a/src/readelf.c b/src/readelf.c
index 2ccbea5b7..470a94eb4 100644
--- a/src/readelf.c
+++ b/src/readelf.c
@@ -7588,7 +7588,7 @@ print_debug_units (Dwfl_Module *dwflmod,
   do
     {
       Dwarf_Off offset = dwarf_dieoffset (&dies[level]);
-      if (unlikely (offset == ~0ul))
+      if (unlikely (offset == (Dwarf_Off) -1))
 	{
 	  if (!silent)
 	    error (0, 0, gettext ("cannot get DIE offset: %s"),
diff --git a/tests/ChangeLog b/tests/ChangeLog
index b656bee7a..521df52f2 100644
--- a/tests/ChangeLog
+++ b/tests/ChangeLog
@@ -1,3 +1,8 @@
+2018-05-31  Mark Wielaard  <mark@klomp.org>
+
+	* get-units-invalid.c (main): Check dwarf_cuoffset and
+	dwarf_dieoffset.
+
 2018-05-29  Mark Wielaard  <mark@klomp.org>
 
 	* dwarf-die-addr-die.c (check_dbg): Also check subdies, split or
diff --git a/tests/get-units-invalid.c b/tests/get-units-invalid.c
index 58b32c0e6..ba0f818d9 100644
--- a/tests/get-units-invalid.c
+++ b/tests/get-units-invalid.c
@@ -83,7 +83,19 @@ main (int argc, char *argv[])
 	      if (dwarf_ranges (&subdie, 0, &base, &start, &end) != -1)
 		{
 		  printf ("Should NOT have a ranges: %s\n",
-			  dwarf_diename (&result));
+			  dwarf_diename (&subdie));
+		  return -1;
+		}
+	      if (dwarf_cuoffset (&subdie) != (Dwarf_Off) -1)
+		{
+		  printf ("Should NOT have a cuoffset: %s\n",
+			  dwarf_diename (&subdie));
+		  return -1;
+		}
+	      if (dwarf_dieoffset (&subdie) != (Dwarf_Off) -1)
+		{
+		  printf ("Should NOT have a die offset: %s\n",
+			  dwarf_diename (&subdie));
 		  return -1;
 		}
 	    }