VulnerabilityPublished 19 Nov 2024Updated 3 Nov 2025

CVE-2024-50304: Linux kernel · ipv4: ip_tunnel: Fix suspicious RCU usage warning in ip_tunnel_find()

Source GCVE Database

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Not known to be exploited · CVSS 5.5 Medium.

Data as of 30 Oct 2026, 00:42 UTC

CVSS 3.1 base score

5.5Medium

How severe the flaw is on the 0–10 CVSS scale.

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Attack Vector: Local
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Local: The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either: the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or remotely (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., tricking a legitimate user into opening a malicious document).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 19 Nov 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

ghsa-259q-92w6-wrgj

What to do

AI-suggested

A fix is available that adds a lockdep expression to validate mutex holding during RCU list traversal in ip_tunnel_find(). Users should update to a Linux kernel version that includes this fix. Since this is a synchronization warning fix, no additional mitigation steps are necessary beyond applying the official patch when available.

Description

CVE-2024-50304 addresses a suspicious Read-Copy-Update (RCU) usage warning in the ip_tunnel_find() function of the Linux kernel's IPv4 tunnel implementation. The issue arises because the per-network namespace IP tunnel hash table is protected by the RTNL mutex, and ip_tunnel_find() is only called when this mutex is held. The fix involves adding a lockdep expression to validate that the mutex is held during RCU list traversal, thereby silencing the warning and ensuring proper synchronization.

Impact

The vulnerability does not impact confidentiality or integrity but can cause a kernel warning related to improper RCU usage, which may affect system stability or debugging clarity. The CVSS score is 5.5 (medium severity) with no confidentiality or integrity impact but with a high impact on availability (kernel stability). There are no known exploits in the wild.

Summary

This vulnerability concerns the Linux kernel's IPv4 tunneling code where ip_tunnel_find() traverses an RCU-protected list without proper reader-side locking validation, triggering a suspicious RCU usage warning. The IP tunnel hash table is protected by the RTNL mutex, which is held during calls to ip_tunnel_find(). The fix adds a lockdep assertion to hlist_for_each_entry_rcu() within ip_tunnel_find() to confirm the RTNL mutex is held, preventing the warning and ensuring correct locking semantics. This change addresses a kernel debugging warning rather than a direct security flaw exploitable for confidentiality or integrity breaches.

References

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