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From 09dd135df9ebc7a4b640537e23e26a03a288a789 Mon Sep 17 00:00:00 2001
From: Alan Modra <amodra@gmail.com>
Date: Wed, 9 Oct 2019 00:07:29 +1030
Subject: [PATCH] PR25078, stack overflow in function find_abstract_instance
Selectively backporting fix for bfd/dwarf2.c, but not the ChangeLog
file. There are newer versions of binutils, but none of them contain the
commit fixing CVE-2019-17450, so backport it to master and zeus.
Upstream-Status: Backport [https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=063c511bd79]
CVE: CVE-2019-17450
Signed-off-by: Trevor Gamblin <trevor.gamblin@windriver.com>
PR 25078
* dwarf2.c (find_abstract_instance): Delete orig_info_ptr, add
recur_count. Error on recur_count reaching 100 rather than
info_ptr matching orig_info_ptr. Adjust calls.
---
bfd/dwarf2.c | 35 +++++++++++++++++------------------
1 file changed, 17 insertions(+), 18 deletions(-)
diff --git a/bfd/dwarf2.c b/bfd/dwarf2.c
index 0b4e485582..20ec9e2e56 100644
--- a/bfd/dwarf2.c
+++ b/bfd/dwarf2.c
@@ -2803,13 +2803,13 @@ lookup_symbol_in_variable_table (struct comp_unit *unit,
}
static bfd_boolean
-find_abstract_instance (struct comp_unit * unit,
- bfd_byte * orig_info_ptr,
- struct attribute * attr_ptr,
- const char ** pname,
- bfd_boolean * is_linkage,
- char ** filename_ptr,
- int * linenumber_ptr)
+find_abstract_instance (struct comp_unit *unit,
+ struct attribute *attr_ptr,
+ unsigned int recur_count,
+ const char **pname,
+ bfd_boolean *is_linkage,
+ char **filename_ptr,
+ int *linenumber_ptr)
{
bfd *abfd = unit->abfd;
bfd_byte *info_ptr;
@@ -2820,6 +2820,14 @@ find_abstract_instance (struct comp_unit * unit,
struct attribute attr;
const char *name = NULL;
+ if (recur_count == 100)
+ {
+ _bfd_error_handler
+ (_("DWARF error: abstract instance recursion detected"));
+ bfd_set_error (bfd_error_bad_value);
+ return FALSE;
+ }
+
/* DW_FORM_ref_addr can reference an entry in a different CU. It
is an offset from the .debug_info section, not the current CU. */
if (attr_ptr->form == DW_FORM_ref_addr)
@@ -2939,15 +2947,6 @@ find_abstract_instance (struct comp_unit * unit,
info_ptr, info_ptr_end);
if (info_ptr == NULL)
break;
- /* It doesn't ever make sense for DW_AT_specification to
- refer to the same DIE. Stop simple recursion. */
- if (info_ptr == orig_info_ptr)
- {
- _bfd_error_handler
- (_("DWARF error: abstract instance recursion detected"));
- bfd_set_error (bfd_error_bad_value);
- return FALSE;
- }
switch (attr.name)
{
case DW_AT_name:
@@ -2961,7 +2960,7 @@ find_abstract_instance (struct comp_unit * unit,
}
break;
case DW_AT_specification:
- if (!find_abstract_instance (unit, info_ptr, &attr,
+ if (!find_abstract_instance (unit, &attr, recur_count + 1,
&name, is_linkage,
filename_ptr, linenumber_ptr))
return FALSE;
@@ -3175,7 +3174,7 @@ scan_unit_for_symbols (struct comp_unit *unit)
case DW_AT_abstract_origin:
case DW_AT_specification:
- if (!find_abstract_instance (unit, info_ptr, &attr,
+ if (!find_abstract_instance (unit, &attr, 0,
&func->name,
&func->is_linkage,
&func->file,
--
2.23.0
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