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CVE Record

CVE-2023-53327: iommufd/selftest: Catch overflow of uptr and length

In the Linux kernel, the following vulnerability has been resolved: iommufd/selftest: Catch overflow of uptr and length syzkaller hits a WARN_ON when trying to have a uptr close to UINTPTR_MAX: WARNING: CPU: 1 PID: 393 at drivers/iommu/iommufd/selftest.c:403 iommufd_test+0xb19/0x16f0 Modules linked in: CPU: 1 PID: 393 Comm: repro Not tainted 6.2.0-c9c3395d5e3d #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 RIP: 0010:iommufd_test+0xb19/0x16f0 Code: 94 c4 31 ff 44 89 e6 e8 a5 54 17 ff 45 84 e4 0f 85 bb 0b 00 00 41 be fb ff ff ff e8 31 53 17 ff e9 a0 f7 ff ff e8 27 53 17 ff <0f> 0b 41 be 8 RSP: 0018:ffffc90000eabdc0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff8214c487 RDX: 0000000000000000 RSI: ffff88800f5c8000 RDI: 0000000000000002 RBP: ffffc90000eabe48 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000001 R11: 0000000000000000 R12: 00000000cd2b0000 R13: 00000000cd2af000 R14: 0000000000000000 R15: ffffc90000eabe68 FS: 00007f94d76d5740(0000) GS:ffff88807dd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000043 CR3: 0000000006880006 CR4: 0000000000770ee0 PKRU: 55555554 Call Trace: <TASK> ? write_comp_data+0x2f/0x90 iommufd_fops_ioctl+0x1ef/0x310 __x64_sys_ioctl+0x10e/0x160 ? __pfx_iommufd_fops_ioctl+0x10/0x10 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x72/0xdc Check that the user memory range doesn't overflow.

MediumCVSS 5.5Not 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 issue in iommufd selftest handling where a local user can supply a user pointer and length that overflow. The reported impact is availability only, not data theft or tampering. It matters most on systems where untrusted users or workloads can run local code.

Executive priority

Treat as a moderate availability risk. It is not described as remote code execution or data exposure, but local denial-of-service risk can be material on shared Linux infrastructure. Patch through normal kernel maintenance, faster for multi-user or workload-hosting systems.

Technical view

The flaw is an integer range-overflow check failure in drivers/iommu/iommufd/selftest.c. Syzkaller triggered a WARN_ON via ioctl with a user pointer near UINTPTR_MAX. CVSS 3.1 is 5.5: local attack vector, low complexity, low privileges, no user interaction, high availability impact.

Likely exposure

Exposure is limited to Linux systems running affected kernel versions with local users or workloads able to reach the relevant iommufd selftest ioctl path. The provided affected-version data is incomplete and should be verified against distro kernel advisories and the referenced stable commits.

Exploitation context

The bundle does not show active exploitation, and KEV is false. The known trigger came from syzkaller fuzzing. Based on CVSS, exploitation requires local low-privileged access and is expected to affect availability rather than confidentiality or integrity.

Researcher notes

Evidence points to a missing overflow guard for user memory range validation in iommufd selftest ioctl handling. The public bundle does not include exploit details, distro-specific impact, or complete version-range semantics. Use the stable commit references and vendor advisories for precise branch mapping.

Mitigation direction

  • Update to a kernel or vendor distro package containing the referenced stable fixes.
  • Check Linux distribution advisories for exact fixed package versions.
  • Prioritize shared, multi-tenant, CI, developer, and virtualization hosts.
  • Apply normal local-access hardening for systems running untrusted code.
  • Avoid direct wrangler or deployment conclusions; this is kernel-level, not application-level.

Validation and detection

  • Inventory Linux kernel versions across affected fleets.
  • Compare running kernels with vendor advisories and referenced stable commits.
  • Confirm whether untrusted local users or workloads exist on those systems.
  • Review kernel logs for iommufd-related WARN_ON availability events.
  • Track remediation through package manager or image baseline evidence.
Prepared
Confidence
medium
Sources
5

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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CVE-2023-53327 mapping review

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Vulnerability profileCVE Program record
Severity
Medium
CVSS
5.5 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:L/AC:L/PR:L/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.

1CVSS vectors
3Timeline events
1ADP providers
4Source 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
5.5CVSS 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

5.5Medium
CVSS 3.1 vector shape for CVE-2023-53327Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:L/AC:L/PR:L/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
LinuxLinuxf4b20bb34c83dceade5470288f48f94ce3598ada, f4b20bb34c83dceade5470288f48f94ce3598ada, f4b20bb34c83dceade5470288f48f94ce3598adaunaffected
LinuxLinux6.2, 0, 6.2.15, 6.3.2, 6.4affected
Weakness

CWE details

No CWE listed

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