From: Alan Modra <amodra@gmail.com>
Date: Thu, 14 Dec 2023 23:34:48 +0000 (+1030)
Subject: Re: readelf..debug-dump=loc displays bogus base addresses
X-Git-Tag: binutils-2_42~573
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=e838a672aa787fb593d4819fa4836cad7db49e66;p=thirdparty%2Fbinutils-gdb.git

Re: readelf..debug-dump=loc displays bogus base addresses

Commit b05efa39b479 removed checks I added in commit f22f27f46c75 to
prevent segfaults when debug_info_p is NULL, which can be the case
with fuzzed objects.  Restore those checks.  Also, for dwo look at
rnglists_dwo rather than rnglists.
---

diff --git a/binutils/dwarf.c b/binutils/dwarf.c
index 15046909bd0..b5e5ea8f8f3 100644
--- a/binutils/dwarf.c
+++ b/binutils/dwarf.c
@@ -2771,7 +2771,9 @@ read_and_display_attr_value (unsigned long attribute,
 
 	  if (form == DW_FORM_loclistx)
 	    {
-	      if (dwo)
+	      if (debug_info_p == NULL)
+		idx = -1;
+	      else if (dwo)
 		{
 		  idx = fetch_indexed_offset (uvalue, loclists_dwo,
 					      debug_info_p->loclists_base,
@@ -2779,7 +2781,7 @@ read_and_display_attr_value (unsigned long attribute,
 		  if (idx != (uint64_t) -1)
 		    idx += (offset_size == 8) ? 20 : 12;
 		}
-	      else if (debug_info_p == NULL || dwarf_version > 4)
+	      else if (dwarf_version > 4)
 		{
 		  idx = fetch_indexed_offset (uvalue, loclists,
 					      debug_info_p->loclists_base,
@@ -2804,21 +2806,13 @@ read_and_display_attr_value (unsigned long attribute,
 	    }
 	  else if (form == DW_FORM_rnglistx)
 	    {
-	      if (dwo)
-		{
-		  idx = fetch_indexed_offset (uvalue, rnglists,
-					      debug_info_p->rnglists_base,
-					      debug_info_p->offset_size);
-		}
+	      if (debug_info_p == NULL)
+		idx = -1;
 	      else
-		{
-		  if (debug_info_p == NULL)
-		    base = 0;
-		  else
-		    base = debug_info_p->rnglists_base;
-		  idx = fetch_indexed_offset (uvalue, rnglists, base,
-					      debug_info_p->offset_size);
-		}
+		idx = fetch_indexed_offset (uvalue,
+					    dwo ? rnglists_dwo : rnglists,
+					    debug_info_p->rnglists_base,
+					    debug_info_p->offset_size);
 	    }
 	  else
 	    {