Re: [PATCH net 1/2] vsock/virtio: discard packets if the transport changes

[Michal Luczaj <mhal@rbox.co>]

On 1/21/25 18:30, Luigi Leonardi wrote:
> On Thu, Jan 09, 2025 at 02:34:28PM +0100, Michal Luczaj wrote:
>> FWIW, I've tried simplifying Hyunwoo's repro to toy with some tests. 
>> Ended
>> up with
>>
>> ```
>>from threading import *
>>from socket import *
>>from signal import *
>>
>> def listener(tid):
>> 	while True:
>> 		s = socket(AF_VSOCK, SOCK_SEQPACKET)
>> 		s.bind((1, 1234))
>> 		s.listen()
>> 		pthread_kill(tid, SIGUSR1)
>>
>> signal(SIGUSR1, lambda *args: None)
>> Thread(target=listener, args=[get_ident()]).start()
>>
>> while True:
>> 	c = socket(AF_VSOCK, SOCK_SEQPACKET)
>> 	c.connect_ex((1, 1234))
>> 	c.connect_ex((42, 1234))
>> ```
>>
>> which gives me splats with or without this patch.
>>
>> That said, when I apply this patch, but drop the `sk->sk_state !=
>> TCP_LISTEN &&`: no more splats.
>>
> Hi Michal,
> 
> I think it would be nice to have this test in the vsock test suite.  
> WDYT? If you don't have any plans to port this to C, I can take care of 
> it :)

Sure, go ahead, but note that this is just a (probably suboptimal) Python
version of Hyunwoo's C repro[1].

[1]: https://lore.kernel.org/netdev/Z2LvdTTQR7dBmPb5@v4bel-B760M-AORUS-ELITE-AX/