From: Eric Anholt <eric@anholt.net>
Date: Tue, 8 Jan 2019 19:45:16 +0000 (-0800)
Subject: glsl: Fix buffer overflow with an atomic buffer binding out of range.
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=700aeaf9c863ea545fe529c1a7fcbc8e87c9adb4;p=mesa.git

glsl: Fix buffer overflow with an atomic buffer binding out of range.

The binding is checked against the limits later in the function, so we
need to make sure we don't overflow before the check here.

Fixes this valgrind warning (and sometimes segfault):

==1460== Invalid write of size 4
==1460==    at 0x74C98DD: ast_declarator_list::hir(exec_list*, _mesa_glsl_parse_state*) (ast_to_hir.cpp:4943)
==1460==    by 0x74C054F: _mesa_ast_to_hir(exec_list*, _mesa_glsl_parse_state*) (ast_to_hir.cpp:159)
==1460==    by 0x7435C12: _mesa_glsl_compile_shader (glsl_parser_extras.cpp:2130)

in

dEQP-GLES31.functional.debug.negative_coverage.get_error.compute.
   exceed_atomic_counters_limit

Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>
---

diff --git a/src/compiler/glsl/ast_to_hir.cpp b/src/compiler/glsl/ast_to_hir.cpp
index 8fdc1890ab0..611cfabbd03 100644
--- a/src/compiler/glsl/ast_to_hir.cpp
+++ b/src/compiler/glsl/ast_to_hir.cpp
@@ -4940,7 +4940,8 @@ ast_declarator_list::hir(exec_list *instructions,
              && process_qualifier_constant(state, &loc, "offset",
                                         type->qualifier.offset,
                                         &qual_offset)) {
-            state->atomic_counter_offsets[qual_binding] = qual_offset;
+            if (qual_binding < ARRAY_SIZE(state->atomic_counter_offsets))
+               state->atomic_counter_offsets[qual_binding] = qual_offset;
          }
       }