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CVE Record

CVE-2023-53474: x86/MCE/AMD: Use an u64 for bank_map

In the Linux kernel, the following vulnerability has been resolved: x86/MCE/AMD: Use an u64 for bank_map Thee maximum number of MCA banks is 64 (MAX_NR_BANKS), see a0bc32b3cacf ("x86/mce: Increase maximum number of banks to 64"). However, the bank_map which contains a bitfield of which banks to initialize is of type unsigned int and that overflows when those bit numbers are >= 32, leading to UBSAN complaining correctly: UBSAN: shift-out-of-bounds in arch/x86/kernel/cpu/mce/amd.c:1365:38 shift exponent 32 is too large for 32-bit type 'int' Change the bank_map to a u64 and use the proper BIT_ULL() macro when modifying bits in there. [ bp: Rewrite commit message. ]

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

CVE-2023-53474 is a Linux kernel bug in AMD x86 machine-check handling. A 32-bit bitfield was used where up to 64 hardware error banks may exist, causing an out-of-bounds shift detected by UBSAN. Public sources do not provide a CVSS score, confirmed exploitation, or business-impact severity.

Executive priority

Handle through normal kernel patch management unless your vendor assigns higher severity. There is no cited evidence of exploitation, but kernel correctness issues can affect system reliability and should not remain indefinitely unresolved on AMD x86 fleets.

Technical view

The vulnerable code is in arch/x86/kernel/cpu/mce/amd.c. bank_map was an unsigned int, but MAX_NR_BANKS can be 64. Setting bits 32 or higher can overflow the type. The kernel fix changes bank_map to u64 and uses BIT_ULL(). Multiple stable branch commits are referenced.

Likely exposure

Most relevant exposure is Linux systems using affected kernel versions on x86 AMD platforms where the AMD MCE path is used. The CVE record lists Linux kernel versions including 5.10, 5.15.111, 6.1.28, 6.2.15, 6.3.2, and 6.4 as affected data points.

Exploitation context

No active exploitation is reported in the provided sources, and the CVE is not marked KEV. The public description shows a correctness and undefined-behavior issue surfaced by UBSAN, not a documented remote attack path. Impact details beyond the kernel warning are not provided.

Researcher notes

The core issue is type width mismatch in AMD MCE bank_map handling. Sources do not define CVSS, CWE, exploitability, or user-trigger conditions. Analysis should focus on affected kernel branch mapping, AMD hardware relevance, and whether distro kernels include the u64/BIT_ULL fix.

Mitigation direction

  • Update affected Linux kernels to versions containing the referenced stable fixes.
  • Check your Linux distribution advisory for packaged kernel status and backports.
  • Prioritize AMD x86 hosts if rapid triage is required.
  • If no vendor package exists, follow kernel vendor guidance before custom patching.

Validation and detection

  • Inventory running kernel versions across Linux systems.
  • Identify AMD x86 systems using the affected kernel lines.
  • Confirm whether the relevant stable commit is present or backported.
  • Review kernel logs for matching UBSAN shift-out-of-bounds messages.
  • Track distribution security advisories for this CVE.
Prepared
Confidence
medium
Sources
8

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-2023-53474 mapping review

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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
0ADP providers
7Source links

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.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinuxa0bc32b3cacf194dc479b342f006203fd1e1941a, a0bc32b3cacf194dc479b342f006203fd1e1941a, a0bc32b3cacf194dc479b342f006203fd1e1941a, a0bc32b3cacf194dc479b342f006203fd1e1941a, a0bc32b3cacf194dc479b342f006203fd1e1941a, a0bc32b3cacf194dc479b342f006203fd1e1941aunaffected
LinuxLinux5.10, 0, 5.10.180, 5.15.111, 6.1.28, 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.