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CVE Record

CVE-2025-22059: udp: Fix multiple wraparounds of sk->sk_rmem_alloc.

In the Linux kernel, the following vulnerability has been resolved: udp: Fix multiple wraparounds of sk->sk_rmem_alloc. __udp_enqueue_schedule_skb() has the following condition: if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf) goto drop; sk->sk_rcvbuf is initialised by net.core.rmem_default and later can be configured by SO_RCVBUF, which is limited by net.core.rmem_max, or SO_RCVBUFFORCE. If we set INT_MAX to sk->sk_rcvbuf, the condition is always false as sk->sk_rmem_alloc is also signed int. Then, the size of the incoming skb is added to sk->sk_rmem_alloc unconditionally. This results in integer overflow (possibly multiple times) on sk->sk_rmem_alloc and allows a single socket to have skb up to net.core.udp_mem[1]. For example, if we set a large value to udp_mem[1] and INT_MAX to sk->sk_rcvbuf and flood packets to the socket, we can see multiple overflows: # cat /proc/net/sockstat | grep UDP: UDP: inuse 3 mem 7956736 <-- (7956736 << 12) bytes > INT_MAX * 15 ^- PAGE_SHIFT # ss -uam State Recv-Q ... UNCONN -1757018048 ... <-- flipping the sign repeatedly skmem:(r2537949248,rb2147483646,t0,tb212992,f1984,w0,o0,bl0,d0) Previously, we had a boundary check for INT_MAX, which was removed by commit 6a1f12dd85a8 ("udp: relax atomic operation on sk->sk_rmem_alloc"). A complete fix would be to revert it and cap the right operand by INT_MAX: rmem = atomic_add_return(size, &sk->sk_rmem_alloc); if (rmem > min(size + (unsigned int)sk->sk_rcvbuf, INT_MAX)) goto uncharge_drop; but we do not want to add the expensive atomic_add_return() back just for the corner case. Casting rmem to unsigned int prevents multiple wraparounds, but we still allow a single wraparound. # cat /proc/net/sockstat | grep UDP: UDP: inuse 3 mem 524288 <-- (INT_MAX + 1) >> 12 # ss -uam State Recv-Q ... UNCONN -2147482816 ... <-- INT_MAX + 831 bytes skmem:(r2147484480,rb2147483646,t0,tb212992,f3264,w0,o0,bl0,d14468947) So, let's define rmem and rcvbuf as unsigned int and check skb->truesize only when rcvbuf is large enough to lower the overflow possibility. Note that we still have a small chance to see overflow if multiple skbs to the same socket are processed on different core at the same time and each size does not exceed the limit but the total size does. Note also that we must ignore skb->truesize for a small buffer as explained in commit 363dc73acacb ("udp: be less conservative with sock rmem accounting").

HighCVSS 7.5Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

A Linux UDP receive-memory accounting flaw can let one socket consume excessive kernel memory, potentially exhausting resources and disrupting service. The issue is remotely reachable according to the supplied CVSS assessment, but the source description indicates that unusually large receive-buffer and UDP memory settings materially influence practical exposure.

Executive priority

Treat as a high-priority availability risk for internet-facing or operationally critical Linux UDP services. Accelerate patching where large receive buffers or generous UDP memory limits are used. Other systems should follow normal high-severity remediation timelines after version and configuration validation.

Technical view

Signed integer wraparound in sk_rmem_alloc can bypass the UDP receive-buffer limit after incoming packet memory is charged. Repeated wraparounds may permit queued socket buffers up to the configured udp_mem threshold. The correction changes accounting comparisons to unsigned values and adds an overflow-aware size check, although the source notes a small concurrency-related overflow possibility remains.

Likely exposure

Prioritize Linux systems running affected kernels that expose UDP services and permit exceptionally large socket receive buffers or UDP memory limits. The bundle identifies affected releases including 6.10, 6.12.23, 6.13.11, 6.14.2, and 6.15, but does not provide sufficiently clear version-range semantics for definitive fleet matching.

Exploitation context

CVSS 3.1 rates this 7.5: network-accessible, low complexity, no privileges or user interaction, with high availability impact. The bundle does not report confidentiality or integrity impact. It is not listed as KEV, and the provided sources do not establish active exploitation or a public weaponized exploit.

Researcher notes

The vulnerable behavior follows removal of an earlier INT_MAX boundary check in commit 6a1f12dd85a8. The supplied record contains duplicate commit identifiers and ambiguous affected-version entries, including “0”; therefore, downstream vendor package advisories should determine exact exposure. The upstream discussion explicitly acknowledges a residual, low-probability concurrent accounting overflow.

Mitigation direction

  • Update to a vendor-supported kernel containing the applicable linked stable fix.
  • Confirm exact affected and corrected package versions through your Linux distribution's security guidance.
  • Restrict unnecessary externally reachable UDP services until remediation is complete.
  • Review unusually large receive-buffer and udp_mem settings, preserving documented operational requirements.
  • Monitor UDP socket memory consumption and host memory pressure for abnormal growth.

Validation and detection

  • Inventory kernel versions across systems exposing UDP services.
  • Map distribution kernel packages to the linked upstream stable fixes.
  • Review receive-buffer, udp_mem, and privileged SO_RCVBUFFORCE usage for elevated exposure.
  • Check UDP socket statistics for abnormal memory growth or negative receive-queue accounting.
  • After updating, confirm the running kernel package includes the vendor's correction.
Prepared
Confidence
medium
Sources
6

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

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ATT&CK lookup starting points

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cwe · low confidence lookup

CWE-190: Exact CWE lookup

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cve · low confidence lookup

CVE-2025-22059 mapping review

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Vulnerability profileCVE Program record
Severity
High
CVSS
7.5 (3.1)
Known Exploited
No
Published

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

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

2CVSS vectors
3Timeline events
1ADP providers
5Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: partial

CVSS vector scores

2 official scores

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
7.5CVSS 3.1HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H3.93.6Linux
5.5CVSS 3.1MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H1.83.6CISA-ADP

Vulnerability scoring details

Base CVSS 3.1 score

7.5High
CVSS 3.1 vector shape for CVE-2025-22059Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

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

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
cvssV3_1other:ssvc

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux6a1f12dd85a8b24f871dfcf467378660af9c064d, 6a1f12dd85a8b24f871dfcf467378660af9c064d, 6a1f12dd85a8b24f871dfcf467378660af9c064d, 6a1f12dd85a8b24f871dfcf467378660af9c064dunaffected
LinuxLinux6.10, 0, 6.12.23, 6.13.11, 6.14.2, 6.15affected
Weakness

CWE details

CWE-190

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CWE-190 · source CWE mapping

Integer Overflow or Wraparound

Integer Overflow or Wraparound represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

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