On 1/21/25 18:30, Luigi Leonardi wrote:

On Thu, Jan 09, 2025 at 02:34:28PM +0100, Michal Luczaj wrote:

quoted

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/ (local)