Re: [PATCH] drm/vc4: fix krealloc() memory leak

["Alexander A. Klimov" <grandmaster@al2klimov.de>]

On 5/28/26 20:17, Maíra Canal wrote:
> Hi Alexander,
> 
> LGTM, but a small styling nit:
> 
> On 26/05/26 15:41, Alexander A. Klimov wrote:
>> Don't just overwrite the original pointer passed to krealloc()
>> with its return value without checking latter:
>>
>>      MEM = krealloc(MEM, SZ, GFP);
>>
>> If krealloc() returns NULL, that erases the pointer
>> to the still allocated memory, hence leaks this memory.
>> Instead, use a temporary variable, check it's not NULL
>> and only then assign it to the original pointer:
>>
>>      TMP = krealloc(MEM, SZ, GFP);
>>      if (!TMP) return;
>>      MEM = TMP;
>>
>> Fixes: 6d45c81d229d ("drm/vc4: Add support for branching in shader validation.")
>> Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de>
>> ---
>>   drivers/gpu/drm/vc4/vc4_validate_shaders.c | 12 ++++++------
>>   1 file changed, 6 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/vc4/vc4_validate_shaders.c b/drivers/gpu/drm/vc4/vc4_validate_shaders.c
>> index d48cf76983c0..af48758592f9 100644
>> --- a/drivers/gpu/drm/vc4/vc4_validate_shaders.c
>> +++ b/drivers/gpu/drm/vc4/vc4_validate_shaders.c
>> @@ -291,14 +291,14 @@ static bool require_uniform_address_uniform(struct vc4_validated_shader_info *va
>>       uint32_t o = validated_shader->num_uniform_addr_offsets;
>>       uint32_t num_uniforms = validated_shader->uniforms_size / 4;
> 
> Declare the variable here.

Strange...
It comes already directly after num_uniforms, doesn't it?
At least when I apply my patch to Linus' master.