Re: [PATCH bpf-next v2 1/4] selftests/bpf: Add some null pointer checks

[Muhammad Usama Anjum]

On 5/10/24 2:58 PM, kunwu.chan@xxxxxxxxx wrote:
> From: Kunwu Chan <chentao@xxxxxxxxxx>
> 
> There is a 'malloc' call, which can be unsuccessful.
> This patch will add the malloc failure checking
> to avoid possible null dereference.
> 
> Signed-off-by: Kunwu Chan <chentao@xxxxxxxxxx>
> ---
>  tools/testing/selftests/bpf/test_progs.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/tools/testing/selftests/bpf/test_progs.c b/tools/testing/selftests/bpf/test_progs.c
> index 89ff704e9dad..ecc3ddeceeeb 100644
> --- a/tools/testing/selftests/bpf/test_progs.c
> +++ b/tools/testing/selftests/bpf/test_progs.c
> @@ -582,6 +582,11 @@ int compare_stack_ips(int smap_fd, int amap_fd, int stack_trace_len)
>  
>  	val_buf1 = malloc(stack_trace_len);
>  	val_buf2 = malloc(stack_trace_len);
> +	if (!val_buf1 || !val_buf2) {
> +		err = -ENOMEM;
Return from here instead of going to out where free(val_buf*) is being called.

> +		goto out;
> +	}
> +
>  	cur_key_p = NULL;
>  	next_key_p = &key;
>  	while (bpf_map_get_next_key(smap_fd, cur_key_p, next_key_p) == 0) {
> @@ -1197,6 +1202,8 @@ static int dispatch_thread_send_subtests(int sock_fd, struct test_state *state)
>  	int subtest_num = state->subtest_num;
>  
>  	state->subtest_states = malloc(subtest_num * sizeof(*subtest_state));
> +	if (!state->subtest_states)
> +		return -ENOMEM;
>  
>  	for (int i = 0; i < subtest_num; i++) {
>  		subtest_state = &state->subtest_states[i];

-- 
BR,
Muhammad Usama Anjum