CVE-2025-40248

Summary

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().

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxd021c344051af91f42c5ba9fdedc176740cbd238 < 3f71753935d648082a8279a97d30efe6b85be680affected
LinuxLinuxd021c344051af91f42c5ba9fdedc176740cbd238 < da664101fb4a0de5cb70d2bae6a650df954df2afaffected
LinuxLinuxd021c344051af91f42c5ba9fdedc176740cbd238 < 67432915145848658149683101104e32f9fd6559affected
LinuxLinuxd021c344051af91f42c5ba9fdedc176740cbd238 < eeca93f06df89be5a36305b7b9dae1ed65550dfcaffected
LinuxLinuxd021c344051af91f42c5ba9fdedc176740cbd238 < 5998da5a8208ae9ad7838ba322bccb2bdcd95e81affected
LinuxLinuxd021c344051af91f42c5ba9fdedc176740cbd238 < f1c170cae285e4b8f61be043bb17addc3d0a14b5affected
LinuxLinuxd021c344051af91f42c5ba9fdedc176740cbd238 < ab6b19f690d89ae4709fba73a3c4a7911f495b7aaffected
LinuxLinuxd021c344051af91f42c5ba9fdedc176740cbd238 < 002541ef650b742a198e4be363881439bb9d86b4affected
LinuxLinux3.9affected
LinuxLinux0 < 3.9unaffected
LinuxLinux5.4.302 <= 5.4.*unaffected
LinuxLinux5.10.247 <= 5.10.*unaffected
LinuxLinux5.15.197 <= 5.15.*unaffected
LinuxLinux6.1.159 <= 6.1.*unaffected
LinuxLinux6.6.118 <= 6.6.*unaffected
LinuxLinux6.12.60 <= 6.12.*unaffected
LinuxLinux6.17.10 <= 6.17.*unaffected
LinuxLinux6.18 <= *unaffected

Weaknesses

ADP Enrichment

Additional References

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

References