Re: [PATCH net 2/2] vsock/test: add MSG_PEEK after partial recv test

[Luigi Leonardi <leonardi@redhat.com>]

Hi Arseniy,

On Sun, Apr 05, 2026 at 10:14:26PM +0300, Arseniy Krasnov wrote:
>
>
>02.04.2026 11:18, Luigi Leonardi wrote:
>> Add a test that verifies MSG_PEEK works correctly after a partial
>> recv().
>>
>> This is to test a bug that was present in the `virtio_transport_stream_do_peek()`
>> when computing the number of bytes to copy: After a partial read, the
>> peek function didn't take into consideration the number of bytes that
>> were already read. So peeking the whole buffer would cause a out-of-bounds read,
>> that resulted in a -EFAULT.
>>
>> This test does exactly this: do a partial recv on a buffer, then try to
>> peek the whole buffer content.
>>
>> Signed-off-by: Luigi Leonardi <leonardi@redhat.com>
>> ---
>>  tools/testing/vsock/vsock_test.c | 64 ++++++++++++++++++++++++++++++++++++++++
>>  1 file changed, 64 insertions(+)
>>
>> diff --git a/tools/testing/vsock/vsock_test.c b/tools/testing/vsock/vsock_test.c
>> index 5bd20ccd9335caafe68e8b7a5d02a4deb3d2deec..308f9f8f30d22bec5aaa282356e400d8438fe321 100644
>> --- a/tools/testing/vsock/vsock_test.c
>> +++ b/tools/testing/vsock/vsock_test.c
>> @@ -346,6 +346,65 @@ static void test_stream_msg_peek_server(const struct test_opts *opts)
>>  	return test_msg_peek_server(opts, false);
>>  }
>>
>> +#define PEEK_AFTER_RECV_LEN 100
>
>Hi, may be we can just reuse MSG_PEEK_BUF_LEN which was already used in MSG_PEEK tests ?
>

yep, good idea!

Thanks!