From: Nick Clifton <nickc@redhat.com>
Date: Tue, 10 Feb 2015 17:13:31 +0000 (+0000)
Subject: Fixes for memory access violations triggered by running readelf on fuzzed binaries.
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=03a91817f163986f10cb843f58e2f2cd9186e4f0;p=binutils-gdb.git

Fixes for memory access violations triggered by running readelf on fuzzed binaries.

	PR binutils/17531
	* dwarf.c (process_debug_info): Zero the debug information array
	since correct initialisation cannot be relied upon.
	(process_cu_tu_index): Improve range checks.
---

diff --git a/binutils/ChangeLog b/binutils/ChangeLog
index 93cab7300cd..4befee323ac 100644
--- a/binutils/ChangeLog
+++ b/binutils/ChangeLog
@@ -17,6 +17,11 @@
 	li_prologue_length.
 	(eh_addr_size): Update prototype.
 
+	PR binutils/17531
+	* dwarf.c (process_debug_info): Zero the debug information array
+	since correct initialisation cannot be relied upon.
+	(process_cu_tu_index): Improve range checks.
+
 2015-02-09  Mark Wielaard  <mjw@redhat.com>
 
 	* dwarf.c (read_and_display_attr_value): Handle DW_LANG_Fortran03
diff --git a/binutils/dwarf.c b/binutils/dwarf.c
index 9daf31579a5..426dca58a5e 100644
--- a/binutils/dwarf.c
+++ b/binutils/dwarf.c
@@ -2304,6 +2304,13 @@ process_debug_info (struct dwarf_section *section,
 	  alloc_num_debug_info_entries = num_debug_info_entries = 0;
 	  return 0;
 	}
+      /* PR 17531: file: 92ca3797.
+	 We cannot rely upon the debug_information array being initialised
+	 before it is used.  A corrupt file could easily contain references
+	 to a unit for which information has not been made available.  So
+	 we ensure that the array is zeroed here.  */
+      memset (debug_information, 0, num_units * sizeof * debug_information);
+	 
       alloc_num_debug_info_entries = num_units;
     }
 
@@ -6913,7 +6920,7 @@ process_cu_tu_index (struct dwarf_section *section, int do_display)
   ppool = pindex + nslots * 4;
 
   /* PR 17531: file: 45d69832.  */
-  if (pindex < phash || ppool < phdr)
+  if (pindex < phash || ppool < phdr || (pindex == phash && nslots != 0))
     {
       warn (_("Section %s is too small for %d slots\n"),
 	    section->name, nslots);
@@ -6930,7 +6937,7 @@ process_cu_tu_index (struct dwarf_section *section, int do_display)
       printf (_("  Number of slots:         %d\n\n"), nslots);
     }
 
-  if (ppool > limit)
+  if (ppool > limit || ppool < phdr)
     {
       warn (_("Section %s too small for %d hash table entries\n"),
 	    section->name, nslots);