From: Richard Biener <rguenther@suse.de>
Date: Mon, 17 Jan 2022 14:22:11 +0000 (+0100)
Subject: middle-end/101292 - invalid memory access with warning control
X-Git-Tag: basepoints/gcc-13~1673
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=1374d4b963a6ac2e0ec1645c09e5162e68b009d6;p=thirdparty%2Fgcc.git

middle-end/101292 - invalid memory access with warning control

The warning control falls into the C++ trap of using a reference
to old hashtable contents for a put operation which can end up
re-allocating that before reading from the old freed referenced to
source.  Fixed by introducing a temporary.

2022-01-17  Richard Biener  <rguenther@suse.de>

	PR middle-end/101292
	* diagnostic-spec.c (copy_warning): Make sure to not
	reference old hashtable content on possible resize.
	* warning-control.cc (copy_warning): Likewise.
---

diff --git a/gcc/diagnostic-spec.c b/gcc/diagnostic-spec.c
index a8af229d6773..4341ccfaae91 100644
--- a/gcc/diagnostic-spec.c
+++ b/gcc/diagnostic-spec.c
@@ -195,7 +195,10 @@ copy_warning (location_t to, location_t from)
   else
     {
       if (from_spec)
-	nowarn_map->put (to, *from_spec);
+	{
+	  nowarn_spec_t tem = *from_spec;
+	  nowarn_map->put (to, tem);
+	}
       else
 	nowarn_map->remove (to);
     }
diff --git a/gcc/warning-control.cc b/gcc/warning-control.cc
index f9808bf43920..fa39ecab421a 100644
--- a/gcc/warning-control.cc
+++ b/gcc/warning-control.cc
@@ -206,7 +206,8 @@ void copy_warning (ToType to, FromType from)
 	  gcc_assert (supp);
 
 	  gcc_checking_assert (nowarn_map);
-	  nowarn_map->put (to_loc, *from_spec);
+	  nowarn_spec_t tem = *from_spec;
+	  nowarn_map->put (to_loc, tem);
 	}
       else
 	{