HighCVE-2024-26870

    Linux Kernel: security vulnerability (CVE-2024-26870)

    Published Last modified Sources: Siemens ProductCERT, SUSE, Debian, Red Hat, BSI, EUVD, CVE.org

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    What is affected, what to do

    In the Linux kernel, the following vulnerability has been resolved: NFSv4.2: fix nfs4_listxattr kernel BUG at mm/usercopy.c:102 A call to listxattr() with a buffer size = 0 returns the actual size of the buffer needed for a subsequent call. When size > 0, nfs4_listxattr() does not return an error because either generic_listxattr() or nfs4_listxattr_nfs4_label() consumes exactly all the bytes then size is 0 when calling nfs4_listxattr_nfs4_user() which then triggers the following kernel BUG: [ 99.403778] kernel BUG at mm/usercopy.c:102! [ 99.404063] Internal error: Oops - BUG: 00000000f2000800 [#1] SMP [ 99.408463] CPU: 0 PID: 3310 Comm: python3 Not tainted 6.6.0-61.fc40.aarch64 #1 [ 99.415827] Call trace: [ 99.415985] usercopy_abort+0x70/0xa0 [ 99.416227] __check_heap_object+0x134/0x158 [ 99.416505] check_heap_object+0x150/0x188 [ 99.416696] __check_object_size.part.0+0x78/0x168 [ 99.416886] __check_object_size+0x28/0x40 [ 99.417078] listxattr+0x8c/0x120 [ 99.417252] path_listxattr+0x78/0xe0 [ 99.417476] __arm64_sys_listxattr+0x28/0x40 [ 99.417723] invoke_syscall+0x78/0x100 [ 99.417929] el0_svc_common.constprop.0+0x48/0xf0 [ 99.418186] do_el0_svc+0x24/0x38 [ 99.418376] el0_svc+0x3c/0x110 [ 99.418554] el0t_64_sync_handler+0x120/0x130 [ 99.418788] el0t_64_sync+0x194/0x198 [ 99.418994] Code: aa0003e3 d000a3e0 91310000 97f49bdb (d4210000) Issue is reproduced when generic_listxattr() returns 'system.nfs4_acl', thus calling lisxattr() with size = 16 will trigger the bug.

    Update Linux Kernel to version 5.10.214, Linux Kernel to version 5.15.153, Linux Kernel to version 6.1.83.

    Affected
    • Linux Kernel lt 5.9..5.10.214
    • Linux Kernel lt 5.11..5.15.153
    • Linux Kernel lt 5.16..6.1.83
    • Linux Kernel lt 6.2..6.6.23
    • Linux Kernel lt 6.7..6.7.11
    • Linux Kernel lt 6.8..6.8.2
    Fixed in
    • Linux Kernel 5.10.214
    • Linux Kernel 5.15.153
    • Linux Kernel 6.1.83
    • Linux Kernel 6.6.23
    • Linux Kernel 6.7.11
    • Linux Kernel 6.8.2
    • Linux Kernel 6.9

    Not sure whether and how you are affected? Ask a question about this vulnerability

    Metrics

    7.8

    XIEM Effective CVSS

    Highest available CVSS rating from NVD and vendor data.

    Source: Vendor (CNA), CVSS v3

    7.8

    CVSS v3

    Severity High on the scale from 0 to 10.

    Source: Siemens ProductCERT, SUSE, Debian, Red Hat, BSI, EUVD, CVE.org

    0.3 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 21.1

    Show all metrics
    Severity
    High
    Priority (0–325)

    The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?

    Read in glossary
    47.42 Methodology
    Exploit maturity

    An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.

    Read in glossary
    no public PoC known
    XIEM Effective CVSS

    XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.

    Read in glossary
    7.8 Methodology
    CVSS v3

    CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.

    Read in glossary
    7.8
    EPSS score

    The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“.

    Read in glossary
    0.3 %
    Low — model estimates < 1% exploitation likelihood.
    EPSS percentile

    The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking.

    Read in glossary
    21.1
    Elevated — this CVE ranks above at least 10% of all CVEs scored today.
    KEV status

    The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.

    Read in glossary
    —
    Published
    CISA assessment (SSVC)
    Exploitation: none known · not automatable · Technical impact: partial
    Source: CISA Vulnrichment, as of 28 May 2024

    Detection rules

    No NEOSEC detection rule is available for this vulnerability yet.

    Classification under NIS2 and CRA

    Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.

    NIS2

    NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.

    Read in glossary
    High technical severity: assess and remediate the vulnerability in vulnerability handling under Art. 21(2)(e) NIS2 and document the decision.
    CRA

    The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.

    Read in glossary
    From 11.12.2027, Annex I Part II CRA requires manufacturers of affected products with digital elements to handle vulnerabilities without delay and provide security updates.
    ISO/IEC 27001

    ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.

    Read in glossary
    Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.

    Description

    In the Linux kernel, the following vulnerability has been resolved: NFSv4.2: fix nfs4_listxattr kernel BUG at mm/usercopy.c:102 A call to listxattr() with a buffer size = 0 returns the actual size of the buffer needed for a subsequent call. When size > 0, nfs4_listxattr() does not return an error because either generic_listxattr() or nfs4_listxattr_nfs4_label() consumes exactly all the bytes then size is 0 when calling nfs4_listxattr_nfs4_user() which then triggers the following kernel BUG: [ 99.403778] kernel BUG at mm/usercopy.c:102! [ 99.404063] Internal error: Oops - BUG: 00000000f2000800 [#1] SMP [ 99.408463] CPU: 0 PID: 3310 Comm: python3 Not tainted 6.6.0-61.fc40.aarch64 #1 [ 99.415827] Call trace: [ 99.415985] usercopy_abort+0x70/0xa0 [ 99.416227] __check_heap_object+0x134/0x158 [ 99.416505] check_heap_object+0x150/0x188 [ 99.416696] __check_object_size.part.0+0x78/0x168 [ 99.416886] __check_object_size+0x28/0x40 [ 99.417078] listxattr+0x8c/0x120 [ 99.417252] path_listxattr+0x78/0xe0 [ 99.417476] __arm64_sys_listxattr+0x28/0x40 [ 99.417723] invoke_syscall+0x78/0x100 [ 99.417929] el0_svc_common.constprop.0+0x48/0xf0 [ 99.418186] do_el0_svc+0x24/0x38 [ 99.418376] el0_svc+0x3c/0x110 [ 99.418554] el0t_64_sync_handler+0x120/0x130 [ 99.418788] el0t_64_sync+0x194/0x198 [ 99.418994] Code: aa0003e3 d000a3e0 91310000 97f49bdb (d4210000) Issue is reproduced when generic_listxattr() returns 'system.nfs4_acl', thus calling lisxattr() with size = 16 will trigger the bug. Add check on nfs4_listxattr() to return ERANGE error when it is called with size > 0 and the return value is greater than size.

    Source: siemens_advisory, suse_csaf, Debian Security Advisories, redhat_csaf, BSI CSAF, BSI WID Portal, ENISA EUVD, cvelistv5, NVD (NIST)

    Affected products

    The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.

    Affected products
    Affected versionsFixed in
    LinuxLinux
    • 6.8 – < 6.8.2
    • 5.11 – < 5.15.153
    • 5.16 – < 6.1.83
    • —
    • 6.2 – < 6.6.23
    • 6.7 – < 6.7.11
    • 5.9 – < 5.10.214
    • 6.8.2
    • 5.15.153
    • 6.1.83
    • 6.9
    • 6.6.23
    • 6.7.11
    • 5.10.214

    Vendors and products

    Affected operating systems

    Affected operating systems
    Linuxdebiandebian_linux10.0
    Linuxdebianlinuxbullseye
    Linuxlinuxlinux_kernel—

    References & sources

    Changes to this CVE

    Who changed this CVE and when: NVD (analysis, affected products, CVSS), the CVE publisher (CNA) and additional providers such as CISA (ADP).

    1. Record modifiedLinux

      Show 21 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Referenceadded
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      https://git.kernel.org/stable/c/06e828b3f1b206de08ef520fc46a40b22e1869cb
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      https://git.kernel.org/stable/c/23bfecb4d852751d5e403557dd500bb563313baf
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      https://git.kernel.org/stable/c/251a658bbfceafb4d58c76b77682c8bf7bcfad65
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      https://git.kernel.org/stable/c/4403438eaca6e91f02d272211c4d6b045092396b
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      https://git.kernel.org/stable/c/79cdcc765969d23f4e3d6ea115660c3333498768
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      https://git.kernel.org/stable/c/80365c9f96015bbf048fdd6c8705d3f8770132bf
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      https://git.kernel.org/stable/c/9d52865ff28245fc2134da9f99baff603a24407a
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      https://git.kernel.org/stable/c/06e828b3f1b206de08ef520fc46a40b22e1869cb
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      https://git.kernel.org/stable/c/23bfecb4d852751d5e403557dd500bb563313baf
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      https://git.kernel.org/stable/c/251a658bbfceafb4d58c76b77682c8bf7bcfad65
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      https://git.kernel.org/stable/c/4403438eaca6e91f02d272211c4d6b045092396b
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      https://git.kernel.org/stable/c/79cdcc765969d23f4e3d6ea115660c3333498768
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      https://git.kernel.org/stable/c/80365c9f96015bbf048fdd6c8705d3f8770132bf
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      https://git.kernel.org/stable/c/9d52865ff28245fc2134da9f99baff603a24407a
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      https://git.kernel.org/stable/c/06e828b3f1b206de08ef520fc46a40b22e1869cb Types: Patch
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      https://git.kernel.org/stable/c/23bfecb4d852751d5e403557dd500bb563313baf Types: Patch
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      https://git.kernel.org/stable/c/251a658bbfceafb4d58c76b77682c8bf7bcfad65 Types: Patch
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      Reference typeremoved
      https://git.kernel.org/stable/c/4403438eaca6e91f02d272211c4d6b045092396b Types: Patch
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      Reference typeremoved
      https://git.kernel.org/stable/c/79cdcc765969d23f4e3d6ea115660c3333498768 Types: Patch
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      Reference typeremoved
      https://git.kernel.org/stable/c/80365c9f96015bbf048fdd6c8705d3f8770132bf Types: Patch
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      Reference typeremoved
      https://git.kernel.org/stable/c/9d52865ff28245fc2134da9f99baff603a24407a Types: Patch
      —

      Source identifier: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    2. Record modifiedCVE Program

      Show 24 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Referenceadded
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      https://git.kernel.org/stable/c/06e828b3f1b206de08ef520fc46a40b22e1869cb
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      https://git.kernel.org/stable/c/23bfecb4d852751d5e403557dd500bb563313baf
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      https://git.kernel.org/stable/c/251a658bbfceafb4d58c76b77682c8bf7bcfad65
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      https://git.kernel.org/stable/c/4403438eaca6e91f02d272211c4d6b045092396b
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      https://git.kernel.org/stable/c/79cdcc765969d23f4e3d6ea115660c3333498768
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      https://git.kernel.org/stable/c/80365c9f96015bbf048fdd6c8705d3f8770132bf
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      https://git.kernel.org/stable/c/9d52865ff28245fc2134da9f99baff603a24407a
      Referenceadded
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      https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html
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      https://git.kernel.org/stable/c/06e828b3f1b206de08ef520fc46a40b22e1869cb
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      https://git.kernel.org/stable/c/23bfecb4d852751d5e403557dd500bb563313baf
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      https://git.kernel.org/stable/c/4403438eaca6e91f02d272211c4d6b045092396b
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      https://git.kernel.org/stable/c/79cdcc765969d23f4e3d6ea115660c3333498768
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      https://git.kernel.org/stable/c/80365c9f96015bbf048fdd6c8705d3f8770132bf
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      https://git.kernel.org/stable/c/9d52865ff28245fc2134da9f99baff603a24407a
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      https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html
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      Reference typeremoved
      https://git.kernel.org/stable/c/06e828b3f1b206de08ef520fc46a40b22e1869cb Types: Patch
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      https://git.kernel.org/stable/c/23bfecb4d852751d5e403557dd500bb563313baf Types: Patch
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      https://git.kernel.org/stable/c/251a658bbfceafb4d58c76b77682c8bf7bcfad65 Types: Patch
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      https://git.kernel.org/stable/c/4403438eaca6e91f02d272211c4d6b045092396b Types: Patch
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      https://git.kernel.org/stable/c/79cdcc765969d23f4e3d6ea115660c3333498768 Types: Patch
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      Reference typeremoved
      https://git.kernel.org/stable/c/80365c9f96015bbf048fdd6c8705d3f8770132bf Types: Patch
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      Reference typeremoved
      https://git.kernel.org/stable/c/9d52865ff28245fc2134da9f99baff603a24407a Types: Patch
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      Reference typeremoved
      https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html Types: Mailing List
      —

      Source identifier: af854a3a-2127-422b-91ae-364da2661108

    3. Record modifiedSiemens ADP

      Show 3 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Affected versions (publisher)added
      —
      Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2024/26xxx/CVE-2024-26870.json">CVE-2024-26870</a>
      Referenceadded
      —
      https://cert-portal.siemens.com/productcert/html/ssa-265688.html
      Referenceremoved
      https://cert-portal.siemens.com/productcert/html/ssa-265688.html
      —

      Source identifier: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e

    4. Record modifiedLinux

      CVSS V3.1: AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

      Show the original change
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      CVSSadded
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      AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

      Source identifier: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

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