Mesa (master): glsl: Catch subscripted calls to undeclared subroutines

[Timothy Arceri]

Module: Mesa
Branch: master
Commit: f09c2cefdd53cd61562a994294e9d0630868d2da
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=f09c2cefdd53cd61562a994294e9d0630868d2da

Author: George Barrett <bob at bob131.so>
Date:   Sun Nov 19 21:55:10 2017 +1100

glsl: Catch subscripted calls to undeclared subroutines

generate_array_index fails to check whether the target of a subroutine
call exists in the AST, potentially passing around null ir_rvalue
pointers eventuating in abort/segfault.

Fixes: fd01840c0bd3 ("glsl: add AoA support to subroutines")
Reviewed-by: Timothy Arceri <tarceri at itsqueeze.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=100438

---

 src/compiler/glsl/ast_function.cpp | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/compiler/glsl/ast_function.cpp b/src/compiler/glsl/ast_function.cpp
index d1596c272e..94e0a16a9c 100644
--- a/src/compiler/glsl/ast_function.cpp
+++ b/src/compiler/glsl/ast_function.cpp
@@ -676,8 +676,13 @@ generate_array_index(void *mem_ctx, exec_list *instructions,
       ir_variable *sub_var = NULL;
       *function_name = array->primary_expression.identifier;
 
-      match_subroutine_by_name(*function_name, actual_parameters,
-                               state, &sub_var);
+      if (!match_subroutine_by_name(*function_name, actual_parameters,
+                                    state, &sub_var)) {
+         _mesa_glsl_error(&loc, state, "Unknown subroutine `%s'",
+                          *function_name);
+         *function_name = NULL; /* indicate error condition to caller */
+         return NULL;
+      }
 
       ir_rvalue *outer_array_idx = idx->hir(instructions, state);
       return new(mem_ctx) ir_dereference_array(sub_var, outer_array_idx);