[Mesa-dev] [PATCH v2] mesa: return early with error when shader source count is 0

[Bartosz Tomczyk]

malloc can return valid pointer for zero size allocation,
which causes OOB access later on

v2: Return error if count is 0, clear previous shader source
---
 src/mesa/main/shaderapi.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/mesa/main/shaderapi.c b/src/mesa/main/shaderapi.c
index c41f006eb7..b39b7fd1c4 100644
--- a/src/mesa/main/shaderapi.c
+++ b/src/mesa/main/shaderapi.c
@@ -1009,7 +1009,8 @@ shader_source(struct gl_shader *sh, const GLchar *source)
    }
 
 #ifdef DEBUG
-   sh->SourceChecksum = util_hash_crc32(sh->Source, strlen(sh->Source));
+   sh->SourceChecksum = sh->Source ?
+      util_hash_crc32(sh->Source, strlen(sh->Source)) : 0xFFFFFFFF;
 #endif
 }
 
@@ -1780,7 +1781,8 @@ _mesa_ShaderSource(GLuint shaderObj, GLsizei count,
    if (!sh)
       return;
 
-   if (string == NULL) {
+   if (string == NULL || count == 0) {
+      shader_source(sh, NULL);
       _mesa_error(ctx, GL_INVALID_VALUE, "glShaderSourceARB");
       return;
    }
-- 
2.12.2