[binutils-gdb] PR23685, buffer overflow

[Alan Modra]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=cf93e9c2cf8f8b2566f8fc86e961592b51b5980d

commit cf93e9c2cf8f8b2566f8fc86e961592b51b5980d
Author: Alan Modra <amodra@gmail.com>
Date:   Thu Sep 20 18:23:17 2018 +0930

    PR23685, buffer overflow
    
    	PR 23685
    	* peXXigen.c (pe_print_edata): Correct export address table
    	overflow checks.  Check dataoff against section size too.

Diff:
---
 bfd/ChangeLog  |  6 ++++++
 bfd/peXXigen.c | 11 ++++++-----
 2 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index fef5479..81b9e56 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,5 +1,11 @@
 2018-09-20  Alan Modra  <amodra@gmail.com>
 
+	PR 23685
+	* peXXigen.c (pe_print_edata): Correct export address table
+	overflow checks.  Check dataoff against section size too.
+
+2018-09-20  Alan Modra  <amodra@gmail.com>
+
 	PR 23686
 	* dwarf2.c (read_section): Error when attempting to malloc
 	"(bfd_size_type) -1".
diff --git a/bfd/peXXigen.c b/bfd/peXXigen.c
index 598f2ca..1645ef4 100644
--- a/bfd/peXXigen.c
+++ b/bfd/peXXigen.c
@@ -1661,7 +1661,8 @@ pe_print_edata (bfd * abfd, void * vfile)
 
       dataoff = addr - section->vma;
       datasize = extra->DataDirectory[PE_EXPORT_TABLE].Size;
-      if (datasize > section->size - dataoff)
+      if (dataoff > section->size
+	  || datasize > section->size - dataoff)
 	{
 	  fprintf (file,
 		   _("\nThere is an export table in %s, but it does not fit into that section\n"),
@@ -1778,11 +1779,11 @@ pe_print_edata (bfd * abfd, void * vfile)
 	  edt.base);
 
   /* PR 17512: Handle corrupt PE binaries.  */
-  if (edt.eat_addr + (edt.num_functions * 4) - adj >= datasize
+  /* PR 17512 file: 140-165018-0.004.  */
+  if (edt.eat_addr - adj >= datasize
       /* PR 17512: file: 092b1829 */
-      || (edt.num_functions * 4) < edt.num_functions
-      /* PR 17512 file: 140-165018-0.004.  */
-      || data + edt.eat_addr - adj < data)
+      || (edt.num_functions + 1) * 4 < edt.num_functions
+      || edt.eat_addr - adj + (edt.num_functions + 1) * 4 > datasize)
     fprintf (file, _("\tInvalid Export Address Table rva (0x%lx) or entry count (0x%lx)\n"),
 	     (long) edt.eat_addr,
 	     (long) edt.num_functions);