From bf59c5d5f4f5b8b4da1f5f605cfa546f8029b43d Mon Sep 17 00:00:00 2001
From: Nick Clifton <nickc@redhat.com>
Date: Fri, 3 Nov 2017 13:57:15 +0000
Subject: [PATCH] Fix integer overflow problems when reading an ELF binary with
 corrupt augmentation data.

	PR 22386
	* dwarf.c (read_cie): Use bfd_size_type for
	augmentation_data_len.
	(display_augmentation_data): New function.
	(display_debug_frames): Use it.
	Check for integer overflow when testing augmentation_data_len.

Upstream-Status: Backport
Affects: <= 2.29.1
CVE: CVE-2017-16828 patch2
Signed-off-by: Armin Kuster <akuster@mvista.com>

---
 binutils/ChangeLog | 10 +++++++++
 binutils/dwarf.c   | 65 +++++++++++++++++++++++++++++++++---------------------
 2 files changed, 50 insertions(+), 25 deletions(-)

Index: git/binutils/dwarf.c
===================================================================
--- git.orig/binutils/dwarf.c
+++ git/binutils/dwarf.c
@@ -6577,13 +6577,13 @@ frame_display_row (Frame_Chunk *fc, int
 static unsigned char *
 read_cie (unsigned char *start, unsigned char *end,
 	  Frame_Chunk **p_cie, int *p_version,
-	  unsigned long *p_aug_len, unsigned char **p_aug)
+	  bfd_size_type *p_aug_len, unsigned char **p_aug)
 {
   int version;
   Frame_Chunk *fc;
   unsigned int length_return;
   unsigned char *augmentation_data = NULL;
-  unsigned long augmentation_data_len = 0;
+  bfd_size_type augmentation_data_len = 0;
 
   * p_cie = NULL;
   /* PR 17512: file: 001-228113-0.004.  */
@@ -6653,10 +6653,11 @@ read_cie (unsigned char *start, unsigned
       READ_ULEB (augmentation_data_len);
       augmentation_data = start;
       /* PR 17512: file: 11042-2589-0.004.  */
-      if (augmentation_data_len > (size_t) (end - start))
+      if (augmentation_data_len > (bfd_size_type) (end - start))
 	{
-	  warn (_("Augmentation data too long: %#lx, expected at most %#lx\n"),
-		augmentation_data_len, (unsigned long) (end - start));
+	  warn (_("Augmentation data too long: 0x%s, expected at most %#lx\n"),
+		dwarf_vmatoa ("x", augmentation_data_len),
+		(unsigned long) (end - start));
 	  return end;
 	}
       start += augmentation_data_len;
@@ -6701,6 +6702,31 @@ read_cie (unsigned char *start, unsigned
   return start;
 }
 
+/* Prints out the contents on the augmentation data array.
+   If do_wide is not enabled, then formats the output to fit into 80 columns.  */
+
+static void
+display_augmentation_data (const unsigned char * data, const bfd_size_type len)
+{
+  bfd_size_type i;
+
+  i = printf (_("  Augmentation data:    "));
+
+  if (do_wide || len < ((80 - i) / 3))
+    for (i = 0; i < len; ++i)
+      printf (" %02x", data[i]);
+  else
+    {
+      for (i = 0; i < len; ++i)
+	{
+	  if (i % (80 / 3) == 0)
+	    putchar ('\n');
+	  printf (" %02x", data[i]);
+	}
+    }
+  putchar ('\n');
+}
+
 static int
 display_debug_frames (struct dwarf_section *section,
 		      void *file ATTRIBUTE_UNUSED)
@@ -6729,7 +6755,7 @@ display_debug_frames (struct dwarf_secti
       Frame_Chunk *cie;
       int need_col_headers = 1;
       unsigned char *augmentation_data = NULL;
-      unsigned long augmentation_data_len = 0;
+      bfd_size_type augmentation_data_len = 0;
       unsigned int encoded_ptr_size = saved_eh_addr_size;
       unsigned int offset_size;
       unsigned int initial_length_size;
@@ -6823,16 +6849,8 @@ display_debug_frames (struct dwarf_secti
 	      printf ("  Return address column: %d\n", fc->ra);
 
 	      if (augmentation_data_len)
-		{
-		  unsigned long i;
+		display_augmentation_data (augmentation_data, augmentation_data_len);
 
-		  printf ("  Augmentation data:    ");
-		  for (i = 0; i < augmentation_data_len; ++i)
-		    /* FIXME: If do_wide is FALSE, then we should
-		       add carriage returns at 80 columns...  */
-		    printf (" %02x", augmentation_data[i]);
-		  putchar ('\n');
-		}
 	      putchar ('\n');
 	    }
 	}
@@ -6988,11 +7006,13 @@ display_debug_frames (struct dwarf_secti
 	      READ_ULEB (augmentation_data_len);
 	      augmentation_data = start;
 	      start += augmentation_data_len;
-	      /* PR 17512: file: 722-8446-0.004.  */
-	      if (start >= end || ((signed long) augmentation_data_len) < 0)
+	      /* PR 17512 file: 722-8446-0.004 and PR 22386.  */
+	      if (start >= end
+		  || ((bfd_signed_vma) augmentation_data_len) < 0
+		  || augmentation_data > start)
 		{
-		  warn (_("Corrupt augmentation data length: %lx\n"),
-			augmentation_data_len);
+		  warn (_("Corrupt augmentation data length: 0x%s\n"),
+			dwarf_vmatoa ("x", augmentation_data_len));
 		  start = end;
 		  augmentation_data = NULL;
 		  augmentation_data_len = 0;
@@ -7014,12 +7034,7 @@ display_debug_frames (struct dwarf_secti
 
 	  if (! do_debug_frames_interp && augmentation_data_len)
 	    {
-	      unsigned long i;
-
-	      printf ("  Augmentation data:    ");
-	      for (i = 0; i < augmentation_data_len; ++i)
-		printf (" %02x", augmentation_data[i]);
-	      putchar ('\n');
+	      display_augmentation_data (augmentation_data, augmentation_data_len);
 	      putchar ('\n');
 	    }
 	}