CVE-2025-40248: Linux

High severity, CVSS 7.8. EPSS: 0.2% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: vsock: Ignore signal/timeout on connect() if already established 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/

Affected products

• Linux Linux: from 3.9, before 5.4.302 (fixed in 5.4.302); from 5.5, before 5.10.247 (fixed in 5.10.247); from 5.11, before 5.15.197 (fixed in 5.15.197); from 5.16, before 6.1.159 (fixed in 6.1.159); from 6.2, before 6.6.118 (fixed in 6.6.118); from 6.7, before 6.12.60 (fixed in 6.12.60); …
• Siemens Ruggedcom RST2428P: before V4.0 (fixed in V4.0)

Published 2025-12-04. Last modified 2026-07-30.