Re: [PATCH] tests/qtest: Fix potential NULL pointer dereference in qos_build_main_args()

[Paolo Bonzini <pbonzini@redhat.com>]

On 03/11/20 15:53, AlexChen wrote:
> In qos_build_main_args(), the pointer 'path' is dereferenced before
> checking it is valid, which may lead to NULL pointer dereference.
> So move the assignment to 'cmd_line' after checking 'path' is valid.
> 
> Reported-by: Euler Robot <euler.robot@huawei.com>
> Signed-off-by: Alex Chen <alex.chen@huawei.com>
> ---
>  tests/qtest/fuzz/qos_fuzz.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/tests/qtest/fuzz/qos_fuzz.c b/tests/qtest/fuzz/qos_fuzz.c
> index b943577b8c..cee1a2a60f 100644
> --- a/tests/qtest/fuzz/qos_fuzz.c
> +++ b/tests/qtest/fuzz/qos_fuzz.c
> @@ -70,7 +70,7 @@ static GString *qos_build_main_args(void)
>  {
>      char **path = fuzz_path_vec;
>      QOSGraphNode *test_node;
> -    GString *cmd_line = g_string_new(path[0]);
> +    GString *cmd_line;
>      void *test_arg;
> 
>      if (!path) {
> @@ -79,6 +79,7 @@ static GString *qos_build_main_args(void)
>      }
> 
>      /* Before test */
> +    cmd_line = g_string_new(path[0]);
>      current_path = path;
>      test_node = qos_graph_get_node(path[(g_strv_length(path) - 1)]);
>      test_arg = test_node->u.test.arg;
> 

Queued, thanks.

Paolo