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

Commit Message

Kunwu Chan May 10, 2024, 9:58 a.m. UTC

From: Kunwu Chan <[e-mail]>

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 <[e-mail]>
---
 tools/testing/selftests/bpf/test_progs.c | 7 +++++++
 1 file changed, 7 insertions(+)

Comments

Muhammad Usama Anjum May 10, 2024, 11:20 a.m. UTC | #1

On 5/10/24 2:58 PM, [e-mail] wrote:
> From: Kunwu Chan <[e-mail]>
> 
> 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 <[e-mail]>
> ---
>  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];

Kunwu Chan May 13, 2024, 7 a.m. UTC | #2

On 2024/5/10 19:20, Muhammad Usama Anjum wrote:
> On 5/10/24 2:58 PM, [e-mail] wrote:
>> From: Kunwu Chan <[e-mail]>
>>
>> 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 <[e-mail]>
>> ---
>>   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.
I think it's no harm.  And Unify the processing at the end to achieve 
uniform format.
>> +		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];

Markus Elfring May 13, 2024, 7:52 a.m. UTC | #3

> There is a 'malloc' call, which can be unsuccessful.

                  two calls?


> This patch will add the malloc failure checking
…

Please use imperative wordings for improved change descriptions also in your patches.
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?h=v6.9#n94

Regards,
Markus

Patch

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;
+		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];