Re: [PATCH] fpga: fix potential null pointer deref in fpga_mgr_test_img_load_sgt()

[Marco Pagani]

On 2025-03-12 00:45, Qasim Ijaz wrote:
> fpga_mgr_test_img_load_sgt() allocates memory for sgt using
> kunit_kzalloc() however it does not check if the allocation failed. 
> It then passes sgt to sg_alloc_table(), which passes it to
> __sg_alloc_table(). This function calls memset() on sgt in an attempt to
> zero it out. If the allocation fails then sgt will be NULL and the
> memset will trigger a NULL pointer dereference.
> 
> Fix this by checking the allocation with KUNIT_ASSERT_NOT_ERR_OR_NULL().
> 
> Fixes: ccbc1c302115 ("fpga: add an initial KUnit suite for the FPGA Manager")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Qasim Ijaz <qasdev00@xxxxxxxxx>

Reviewed-by: Marco Pagani <marco.pagani@xxxxxxxxx>

> ---
>  drivers/fpga/tests/fpga-mgr-test.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/fpga/tests/fpga-mgr-test.c b/drivers/fpga/tests/fpga-mgr-test.c
> index 9cb37aefbac4..1902ebf5a298 100644
> --- a/drivers/fpga/tests/fpga-mgr-test.c
> +++ b/drivers/fpga/tests/fpga-mgr-test.c
> @@ -263,6 +263,7 @@ static void fpga_mgr_test_img_load_sgt(struct kunit *test)
>  	img_buf = init_test_buffer(test, IMAGE_SIZE);
>  
>  	sgt = kunit_kzalloc(test, sizeof(*sgt), GFP_KERNEL);
> +	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, sgt);
>  	ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
>  	KUNIT_ASSERT_EQ(test, ret, 0);
>  	sg_init_one(sgt->sgl, img_buf, IMAGE_SIZE);

Thanks,
Marco