On Wed, Jul 29, 2026 at 03:20:38PM +0200, Michal Luczaj wrote:
On 7/29/26 15:03, Stefano Garzarella wrote:
On Wed, Jul 29, 2026 at 05:46:29PM +0800, Nguyen Dinh Phi [SG] wrote:
On 28/7/26 16:21, Stefano Garzarella wrote:
On Fri, Jul 24, 2026 at 03:34:23PM +0800, Nguyen Dinh Phi [SG] wrote:
On 24/7/26 05:43, Michal Luczaj wrote:
On 7/23/26 12:26, Nguyen Dinh Phi [SG] wrote:
...
Yeah, we need to handle that part better, I think it's
a leftover when
we generalized AF_VSOCK to support more transport than vmci.
Speaking of leftovers, I have trouble understanding where
does vsock set
sk_err on listener sockets anyway. If it doesn't, why vsock_accept()
checks for it?
I can't also see where it can be set TBH. Should we remove it ?
I couldn't find it for listener side too.
Removing sk_err handling from vsock_accept() solves the problem, right?
thanks,
Michal
Yes, confirmed, removing sk_err checks from vsock_accept() does
solve the problem.
Okay, so maybe better on going on this direction. WDYT?
Stefano
I'm still a bit concerned about how connect() and poll() interact
here, even with the sk_err checks removed from vsock_accept().
For example:
vsock_accept() now lets us reuse a socket whose connect() failed (call
it r0) as syzbot reproducer does. After listen(), r0 becomes a
listener (sk_state == TCP_LISTEN) and works correctly -- it accepts
connections.
But poll() on r0 still marks POLLERR, even though there is no error on
that socket at that point.
As I understand it, sk_err holds an error that has not yet been
reported to userspace. In the blocking vsock_connect() case we have
already read that error and returned it to the caller, so it is no
longer pending
Shouldn't sk_err be consumed/cleared when vsock_connect() returns it
to userspace?
Yeah, makes sense to me, I'll ack the v2.
@Michal WDYT?
I'm worried this patch does not address the non-blocking connect() case.
Could vsock_connect_timeout() set `sk->sk_err = ETIMEDOUT` after connect()
returns?
This is a good point!
So we still need to remove `sk_err` check in vsock_accept(), or set
`sk->sk_err = 0` in vsock_listen() to have a complete fix, right?
Thanks,
Stefano
