CyberSecBulletin
CVE-2025-68770NVD status: Deferred

Linux: Improper Locking

Published Updated By the CyberSecBulletin desk

CVE-2025-68770 is a high-severity improper locking vulnerability in Linux, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 4b83902a1e67ff327ab5c6c65021a03e72c081d6, f17e0c1208485b24d61271bc1ddc8f2087e71561, 0373d5c387f24de749cc22e694a14b3a7c7eb515 as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.39% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Linux to 4b83902a1e67ff327ab5c6c65021a03e72c081d6 or f17e0c1208485b24d61271bc1ddc8f2087e71561 or 0373d5c387f24de749cc22e694a14b3a7c7eb515, whichever matches your release line, or a later version.
  2. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux7f0a168b0441ef7fd6b46563efb2706c58ac2a4c up to, but not including, 4b83902a1e67ff327ab5c6c65021a03e72c081d6; 7f0a168b0441ef7fd6b46563efb2706c58ac2a4c up to, but not including, f17e0c1208485b24d61271bc1ddc8f2087e71561; 7f0a168b0441ef7fd6b46563efb2706c58ac2a4c up to, but not including, 0373d5c387f24de749cc22e694a14b3a7c7eb515; 6.84b83902a1e67ff327ab5c6c65021a03e72c081d6, f17e0c1208485b24d61271bc1ddc8f2087e71561, 0373d5c387f24de749cc22e694a14b3a7c7eb515

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
NoneNo data is disclosed.
Integrity
NoneNothing can be modified.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by CNA.

Official description

In the Linux kernel, the following vulnerability has been resolved: bnxt_en: Fix XDP_TX path For XDP_TX action in bnxt_rx_xdp(), clearing of the event flags is not correct. __bnxt_poll_work() -> bnxt_rx_pkt() -> bnxt_rx_xdp() may be looping within NAPI and some event flags may be set in earlier iterations. In particular, if BNXT_TX_EVENT is set earlier indicating some XDP_TX packets are ready and pending, it will be cleared if it is XDP_TX action again. Normally, we will set BNXT_TX_EVENT again when we successfully call __bnxt_xmit_xdp(). But if the TX ring has no more room, the flag will not be set. This will cause the TX producer to be ahead but the driver will not hit the TX doorbell. For multi-buf XDP_TX, there is no need to clear the event flags and set BNXT_AGG_EVENT. The BNXT_AGG_EVENT flag should have been set earlier in bnxt_rx_pkt(). The visible symptom of this is that the RX ring associated with the TX XDP ring will eventually become empty and all packets will be dropped. Because this condition will cause the driver to not refill the RX ring seeing that the TX ring has forever pending XDP_TX packets. The fix is to only clear BNXT_RX_EVENT when we have successfully called __bnxt_xmit_xdp().

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Locking

The product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors.

How developers prevent this class of flaw

  • Use industry standard APIs to implement locking mechanism.

More Improper Locking vulnerabilities (CWE-667)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Improper Locking vulnerabilities

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