High severity · published Dec 4, 2025
CVE-2025-40248
vsock: Ignore signal/timeout on connect() if already established
7.8
CVSS
0.2%
EPSS
No
On KEV
Description
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/
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 5% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
LI
Linux · Linux
d021c344051af91f42c5ba9fdedc176740cbd238 before 3f71753935d648082a8279a97d30efe6b85be680; d021c344051af91f42c5ba9fdedc176740cbd238 before da664101fb4a0de5cb70d2bae6a650df954df2af; d021c344051af91f42c5ba9fdedc176740cbd238 before 67432915145848658149683101104e32f9fd6559; d021c344051af91f42c5ba9fdedc176740cbd238 before eeca93f06df89be5a36305b7b9dae1ed65550dfc; d021c344051af91f42c5ba9fdedc176740cbd238 before 5998da5a8208ae9ad7838ba322bccb2bdcd95e81; d021c344051af91f42c5ba9fdedc176740cbd238 before f1c170cae285e4b8f61be043bb17addc3d0a14b5; +3 more · source: vendor
RR
RUGGEDCOM RST2428P · Siemens
before V4.0 · source: CISA