{"cve":"CVE-2025-40248","nvd":{"published":"2025-12-04T16:16:18.240","modified":"2026-10-19T19:10:00.130","status":"Deferred","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nvsock: Ignore signal/timeout on connect() if already established\n\nDuring connect(), acting on a signal/timeout by disconnecting an already\nestablished socket leads to several issues:\n\n1. connect() invoking vsock_transport_cancel_pkt() ->\n   virtio_transport_purge_skbs() may race with sendmsg() invoking\n   virtio_transport_get_credit(). This results in a permanently elevated\n   `vvs->bytes_unsent`. Which, in turn, confuses the SOCK_LINGER handling.\n\n2. connect() resetting a connected socket's state may race with socket\n   being placed in a sockmap. A disconnected socket remaining in a sockmap\n   breaks sockmap's assumptions. And gives rise to WARNs.\n\n3. connect() transitioning SS_CONNECTED -> SS_UNCONNECTED allows for a\n   transport change/drop after TCP_ESTABLISHED. Which poses a problem for\n   any simultaneous sendmsg() or connect() and may result in a\n   use-after-free/null-ptr-deref.\n\nDo not disconnect socket on signal/timeout. Keep the logic for unconnected\nsockets: they don't linger, can't be placed in a sockmap, are rejected by\nsendmsg().\n\n[1]: https://lore.kernel.org/netdev/e07fd95c-9a38-4eea-9638-133e38c2ec9b@rbox.co/\n[2]: https://lore.kernel.org/netdev/20250317-vsock-trans-signal-race-v4-0-fc8837f3f1d4@rbox.co/\n[3]: https://lore.kernel.org/netdev/60f1b7db-3099-4f6a-875e-af9f6ef194f6@rbox.co/","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8},"cwes":[],"references":["https://git.kernel.org/stable/c/002541ef650b742a198e4be363881439bb9d86b4","https://git.kernel.org/stable/c/3f71753935d648082a8279a97d30efe6b85be680","https://git.kernel.org/stable/c/5998da5a8208ae9ad7838ba322bccb2bdcd95e81","https://git.kernel.org/stable/c/67432915145848658149683101104e32f9fd6559","https://git.kernel.org/stable/c/ab6b19f690d89ae4709fba73a3c4a7911f495b7a"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:16:40.427100871+00:00"},"epss":{"cve":"CVE-2025-40248","score":0.00157,"percentile":0.04802,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}