mirror of https://github.com/torvalds/linux.git
During connect(), acting on a signal/timeout by disconnecting an already
established socket leads to several issues:
1. connect() invoking vsock_transport_cancel_pkt() ->
virtio_transport_purge_skbs() may race with sendmsg() invoking
virtio_transport_get_credit(). This results in a permanently elevated
`vvs->bytes_unsent`. Which, in turn, confuses the SOCK_LINGER handling.
2. connect() resetting a connected socket's state may race with socket
being placed in a sockmap. A disconnected socket remaining in a sockmap
breaks sockmap's assumptions. And gives rise to WARNs.
3. connect() transitioning SS_CONNECTED -> SS_UNCONNECTED allows for a
transport change/drop after TCP_ESTABLISHED. Which poses a problem for
any simultaneous sendmsg() or connect() and may result in a
use-after-free/null-ptr-deref.
Do not disconnect socket on signal/timeout. Keep the logic for unconnected
sockets: they don't linger, can't be placed in a sockmap, are rejected by
sendmsg().
[1]: https://lore.kernel.org/netdev/e07fd95c-9a38-4eea-9638-133e38c2ec9b@rbox.co/
[2]: https://lore.kernel.org/netdev/20250317-vsock-trans-signal-race-v4-0-fc8837f3f1d4@rbox.co/
[3]: https://lore.kernel.org/netdev/60f1b7db-3099-4f6a-875e-af9f6ef194f6@rbox.co/
Fixes:
|
||
|---|---|---|
| .. | ||
| Kconfig | ||
| Makefile | ||
| af_vsock.c | ||
| af_vsock_tap.c | ||
| diag.c | ||
| hyperv_transport.c | ||
| virtio_transport.c | ||
| virtio_transport_common.c | ||
| vmci_transport.c | ||
| vmci_transport.h | ||
| vmci_transport_notify.c | ||
| vmci_transport_notify.h | ||
| vmci_transport_notify_qstate.c | ||
| vsock_addr.c | ||
| vsock_bpf.c | ||
| vsock_loopback.c | ||