Re: [PATCH] selftests/bpf: fix signedness bug in redir_partial()
From: Fushuai Wang
Date: Thu Jun 12 2025 - 03:59:39 EST
>> When xsend() returns -1 (error), the check 'n < sizeof(buf)' incorrectly
>> treats it as success due to unsigned promotion. Explicitly check for -1
>> first.
>>
>> Fixes: a4b7193d8efd ("selftests/bpf: Add sockmap test for redirecting partial skb data")
>> Signed-off-by: wangfushuai <wangfushuai@xxxxxxxxx>
>
> Looks good, but please spell out your name as First Last
> in both From and Signed-off
>
> Also use [PATCH bpf-next] in subject
>
> pw-bot: cr
Will fix and send v2 shortly. Thanks for the review!
--
Regards,
Wang
>> ---
>> tools/testing/selftests/bpf/prog_tests/sockmap_listen.c | 2 ++
>> 1 file changed, 2 insertions(+)
>>
>> diff --git a/tools/testing/selftests/bpf/prog_tests/sockmap_listen.c b/tools/testing/selftests/bpf/prog_tests/sockmap_listen.c
>> index 1d98eee7a2c3..f1bdccc7e4e7 100644
>> --- a/tools/testing/selftests/bpf/prog_tests/sockmap_listen.c
>> +++ b/tools/testing/selftests/bpf/prog_tests/sockmap_listen.c
>> @@ -924,6 +924,8 @@ static void redir_partial(int family, int sotype, int sock_map, int parser_map)
>> goto close;
>>
>> n = xsend(c1, buf, sizeof(buf), 0);
>> + if (n == -1)
>> + goto close;
>> if (n < sizeof(buf))
>> FAIL("incomplete write");
>>
>> --
>> 2.36.1