From: Tobias Burnus <tburnus@baylibre.com>
Date: Mon, 31 Mar 2025 09:44:26 +0000 (+0200)
Subject: OpenMP: modify_call_for_omp_dispatch - fix invalid memory access after 'error' [PR119541]
X-Git-Tag: basepoints/gcc-16~490
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f3899e0fd3f9aa6b579a21e87b50c61ea5c448df;p=thirdparty%2Fgcc.git

OpenMP: modify_call_for_omp_dispatch - fix invalid memory access after 'error' [PR119541]

OpenMP requires that the number of dispatch 'interop' clauses (ninterop)
is less or equal to the number of declare variant 'append_args' interop
objects (nappend).

While 'nappend < ninterop' was diagnosed as error, the processing continues,
which lead to an invalid out-of-bounds memory access. Solution: only
process the first nappend 'interop' clauses.

gcc/ChangeLog:

	PR middle-end/119541
	* gimplify.cc (modify_call_for_omp_dispatch): Limit interop claues
	processing by the number of append_args arguments.
---

diff --git a/gcc/gimplify.cc b/gcc/gimplify.cc
index 422ad1265a6..a8399dc8363 100644
--- a/gcc/gimplify.cc
+++ b/gcc/gimplify.cc
@@ -3949,6 +3949,7 @@ modify_call_for_omp_dispatch (tree expr, tree dispatch_clauses,
 		  : DECL_SOURCE_LOCATION (fndecl),
 		  "%<declare variant%> candidate %qD declared here",
 		  fndecl);
+	  ninterop = nappend;
 	}
     }
   if (dispatch_interop && !dispatch_device_num)
@@ -3971,7 +3972,7 @@ modify_call_for_omp_dispatch (tree expr, tree dispatch_clauses,
 	  buffer[i] = CALL_EXPR_ARG (expr, i);
 	}
       int j = ninterop;
-      for (tree t = dispatch_interop; t; t = TREE_CHAIN (t))
+      for (tree t = dispatch_interop; t && j > 0; t = TREE_CHAIN (t))
 	if (OMP_CLAUSE_CODE (t) == OMP_CLAUSE_INTEROP)
 	  buffer[i + --j] = OMP_CLAUSE_DECL (t);
       gcc_checking_assert (j == 0);