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CVE Record

CVE-2024-26901: do_sys_name_to_handle(): use kzalloc() to fix kernel-infoleak

In the Linux kernel, the following vulnerability has been resolved: do_sys_name_to_handle(): use kzalloc() to fix kernel-infoleak syzbot identified a kernel information leak vulnerability in do_sys_name_to_handle() and issued the following report [1]. [1] "BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:114 [inline] BUG: KMSAN: kernel-infoleak in _copy_to_user+0xbc/0x100 lib/usercopy.c:40 instrument_copy_to_user include/linux/instrumented.h:114 [inline] _copy_to_user+0xbc/0x100 lib/usercopy.c:40 copy_to_user include/linux/uaccess.h:191 [inline] do_sys_name_to_handle fs/fhandle.c:73 [inline] __do_sys_name_to_handle_at fs/fhandle.c:112 [inline] __se_sys_name_to_handle_at+0x949/0xb10 fs/fhandle.c:94 __x64_sys_name_to_handle_at+0xe4/0x140 fs/fhandle.c:94 ... Uninit was created at: slab_post_alloc_hook+0x129/0xa70 mm/slab.h:768 slab_alloc_node mm/slub.c:3478 [inline] __kmem_cache_alloc_node+0x5c9/0x970 mm/slub.c:3517 __do_kmalloc_node mm/slab_common.c:1006 [inline] __kmalloc+0x121/0x3c0 mm/slab_common.c:1020 kmalloc include/linux/slab.h:604 [inline] do_sys_name_to_handle fs/fhandle.c:39 [inline] __do_sys_name_to_handle_at fs/fhandle.c:112 [inline] __se_sys_name_to_handle_at+0x441/0xb10 fs/fhandle.c:94 __x64_sys_name_to_handle_at+0xe4/0x140 fs/fhandle.c:94 ... Bytes 18-19 of 20 are uninitialized Memory access of size 20 starts at ffff888128a46380 Data copied to user address 0000000020000240" Per Chuck Lever's suggestion, use kzalloc() instead of kmalloc() to solve the problem.

MediumCVSS 5.3Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

This is a Linux kernel bug where a kernel routine could return a small amount of uninitialized kernel memory to a caller. The upstream fix changes allocation to zero-initialize the buffer. The source bundle shows medium severity and no KEV listing, so this is patch-management priority rather than an emergency.

Executive priority

Treat as a normal but real kernel maintenance item. Prioritize shared Linux hosts, multi-tenant systems, and vendor appliances where kernel exposure is harder to see. No source in the bundle supports emergency response for active exploitation.

Technical view

do_sys_name_to_handle()/name_to_handle_at used kmalloc(), leaving bytes in a file handle structure uninitialized before copy_to_user. KMSAN/syzbot reported bytes 18-19 of a 20-byte copy as uninitialized. The resolved fix uses kzalloc() so the allocation is zeroed before user copy.

Likely exposure

Exposure is Linux systems running affected kernel code or downstream vendor kernels that include it. The bundle lists Linux kernel versions/branches from 2.6.39 through 6.x stable lines, plus Debian LTS package advisories. Backported distro kernels require vendor-specific confirmation rather than raw upstream version matching.

Exploitation context

The bundle does not cite active exploitation, and KEV is false. Public evidence describes automated discovery by syzbot/KMSAN, not attacker use. The CVSS score provided is 5.3 medium; researchers should note the title says information leak while the vector records no confidentiality impact.

Researcher notes

The evidence is strongest for the root cause and upstream remediation: uninitialized allocation in fs/fhandle.c fixed by replacing kmalloc() with kzalloc(). The affected-version data in the bundle is not enough to map every downstream distribution kernel precisely, so package advisory validation is necessary.

Mitigation direction

  • Apply a Linux kernel update that includes the upstream kzalloc() fix for CVE-2024-26901.
  • Use distribution advisories, such as Debian LTS, to identify fixed package versions.
  • Reboot systems after kernel updates so the patched kernel is actually running.
  • For vendor appliances, follow the vendor advisory instead of assuming upstream version equivalence.

Validation and detection

  • Inventory Linux kernel package versions across servers, containers hosts, and appliances.
  • Check whether each vendor package advisory marks CVE-2024-26901 as fixed.
  • Confirm the running kernel after reboot, not only the installed package.
  • For source-built kernels, verify the referenced stable commit is present.
Prepared
Confidence
high
Sources
12

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.

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CVE-2024-26901 mapping review

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Vulnerability profileCVE Program record
Severity
Medium
CVSS
5.3 (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:L

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.

1CVSS vectors
3Timeline events
3ADP providers
14Source links

SSVC decision data

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

CVSS vector scores

1 official score

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
5.3CVSS 3.1MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L3.91.4CISA-ADP

Vulnerability scoring details

Base CVSS 3.1 score

5.3Medium
CVSS 3.1 vector shape for CVE-2024-26901Attack 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:L

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
CVECVE Program Container
siemens-SADPADP container

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux990d6c2d7aee921e3bce22b2d6a750fd552262be, 990d6c2d7aee921e3bce22b2d6a750fd552262be, 990d6c2d7aee921e3bce22b2d6a750fd552262be, 990d6c2d7aee921e3bce22b2d6a750fd552262be, 990d6c2d7aee921e3bce22b2d6a750fd552262be, 990d6c2d7aee921e3bce22b2d6a750fd552262be, 990d6c2d7aee921e3bce22b2d6a750fd552262be, 990d6c2d7aee921e3bce22b2d6a750fd552262be, 990d6c2d7aee921e3bce22b2d6a750fd552262beunaffected
LinuxLinux2.6.39, 0, 4.19.311, 5.4.273, 5.10.214, 5.15.153, 6.1.83, 6.6.23, 6.7.11, 6.8.2, 6.9affected
Weakness

CWE details

No CWE listed

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