[Mesa-dev] [PATCH] mesa: return early with no error when shader source count is 0

[Bartosz Tomczyk]

You are right, it doesn't free old shader source.  Should we also clear 
old source if new source is NULL? Then I could unify both conditions.


On 04.05.2017 19:03, Eric Anholt wrote:
> Bartosz Tomczyk <bartosz.tomczyk86 at gmail.com> writes:
>
>> malloc can return valid pointer for zero size allocation,
>> which causes OOB access later on
>> ---
>>   src/mesa/main/shaderapi.c | 3 +++
>>   1 file changed, 3 insertions(+)
>>
>> diff --git a/src/mesa/main/shaderapi.c b/src/mesa/main/shaderapi.c
>> index c41f006eb7..36cff0ca6e 100644
>> --- a/src/mesa/main/shaderapi.c
>> +++ b/src/mesa/main/shaderapi.c
>> @@ -1776,6 +1776,9 @@ _mesa_ShaderSource(GLuint shaderObj, GLsizei count,
>>      GLcharARB *source;
>>      struct gl_shader *sh;
>>   
>> +   if (!count)
>> +      return;
>> +
> I think this doesn't clear out the shader source when it should.  Maybe
> shader_source(sh, calloc(1, 1)); before returning?