LiveActive security incident?Get immediate response
CVE Record

CVE-2024-35852: mlxsw: spectrum_acl_tcam: Fix memory leak when canceling rehash work

In the Linux kernel, the following vulnerability has been resolved: mlxsw: spectrum_acl_tcam: Fix memory leak when canceling rehash work The rehash delayed work is rescheduled with a delay if the number of credits at end of the work is not negative as supposedly it means that the migration ended. Otherwise, it is rescheduled immediately. After "mlxsw: spectrum_acl_tcam: Fix possible use-after-free during rehash" the above is no longer accurate as a non-negative number of credits is no longer indicative of the migration being done. It can also happen if the work encountered an error in which case the migration will resume the next time the work is scheduled. The significance of the above is that it is possible for the work to be pending and associated with hints that were allocated when the migration started. This leads to the hints being leaked [1] when the work is canceled while pending as part of ACL region dismantle. Fix by freeing the hints if hints are associated with a work that was canceled while pending. Blame the original commit since the reliance on not having a pending work associated with hints is fragile. [1] unreferenced object 0xffff88810e7c3000 (size 256): comm "kworker/0:16", pid 176, jiffies 4295460353 hex dump (first 32 bytes): 00 30 95 11 81 88 ff ff 61 00 00 00 00 00 00 80 .0......a....... 00 00 61 00 40 00 00 00 00 00 00 00 04 00 00 00 ..a.@........... backtrace (crc 2544ddb9): [<00000000cf8cfab3>] kmalloc_trace+0x23f/0x2a0 [<000000004d9a1ad9>] objagg_hints_get+0x42/0x390 [<000000000b143cf3>] mlxsw_sp_acl_erp_rehash_hints_get+0xca/0x400 [<0000000059bdb60a>] mlxsw_sp_acl_tcam_vregion_rehash_work+0x868/0x1160 [<00000000e81fd734>] process_one_work+0x59c/0xf20 [<00000000ceee9e81>] worker_thread+0x799/0x12c0 [<00000000bda6fe39>] kthread+0x246/0x300 [<0000000070056d23>] ret_from_fork+0x34/0x70 [<00000000dea2b93e>] ret_from_fork_asm+0x1a/0x30

UnknownCVSS not scoredNot KEV-listedUpdated
Discuss exposureBack to CVEs
Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

CVE-2024-35852 is a Linux kernel memory leak in the mlxsw Spectrum ACL TCAM code. It can leak allocated rehash hint memory when pending rehash work is canceled during ACL region teardown. The public record does not provide a CVSS score or confirmed exploitation.

Executive priority

Treat as a targeted kernel maintenance issue, not an emergency based on current evidence. Patch affected networking infrastructure during the next appropriate maintenance window, faster where Spectrum switch ASIC systems run production ACL workloads.

Technical view

The flaw is in mlxsw spectrum_acl_tcam rehash work handling. After an earlier use-after-free fix, non-negative credits no longer reliably meant migration completion. Pending work could still retain allocated hints, and canceling that work during ACL region dismantle leaked those hints. Stable kernel commits free associated hints on cancellation.

Likely exposure

Exposure appears limited to Linux systems using the mlxsw Spectrum networking driver and ACL TCAM functionality. The source bundle lists affected Linux kernel versions and stable backport commits but does not identify broader products beyond Linux.

Exploitation context

No active exploitation is supported by the supplied sources. The CVE is not marked KEV, and the available description frames this as a memory leak found through kernel diagnostics rather than a publicly exploited issue.

Researcher notes

The key condition is cancellation of pending delayed rehash work with retained hints during ACL region dismantle. Evidence does not establish attacker reachability, privilege requirements, or impact beyond memory leakage, so validation should focus on affected driver use and backport presence.

Mitigation direction

  • Update to a vendor kernel containing the referenced stable fixes.
  • Check distribution advisories for the exact fixed kernel package.
  • Prioritize systems using Mellanox/NVIDIA Spectrum switching hardware and mlxsw.
  • Follow vendor guidance where kernel version mappings are unclear.

Validation and detection

  • Inventory kernels against the affected and fixed versions in the CVE record.
  • Confirm whether the mlxsw Spectrum driver is present and in use.
  • Check vendor package changelogs for CVE-2024-35852 or the stable commit IDs.
  • Review kernel diagnostics for memory leak indicators if debugging is enabled.
Prepared
Confidence
medium
Sources
10

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

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cve · low confidence lookup

CVE-2024-35852 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
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.

0CVSS vectors
3Timeline events
2ADP providers
9Source links

SSVC decision data

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

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
other:ssvc
CVECVE Program Container

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinuxc9c9af91f1d9a636aecc55302c792538e549a430, c9c9af91f1d9a636aecc55302c792538e549a430, c9c9af91f1d9a636aecc55302c792538e549a430, c9c9af91f1d9a636aecc55302c792538e549a430, c9c9af91f1d9a636aecc55302c792538e549a430, c9c9af91f1d9a636aecc55302c792538e549a430, c9c9af91f1d9a636aecc55302c792538e549a430unaffected
LinuxLinux5.1, 0, 5.4.275, 5.10.216, 5.15.158, 6.1.90, 6.6.30, 6.8.9, 6.9affected
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.