Vulnerability-Lookup

GHSA-8JRG-738Q-V5MW

Vulnerability from github – Published: 2025-09-22 21:30 – Updated: 2025-09-22 21:30

Details

In the Linux kernel, the following vulnerability has been resolved:

powerpc/64s: Don't use DSISR for SLB faults

Since commit 46ddcb3950a2 ("powerpc/mm: Show if a bad page fault on data is read or write.") we use page_fault_is_write(regs->dsisr) in __bad_page_fault() to determine if the fault is for a read or write, and change the message printed accordingly.

But SLB faults, aka Data Segment Interrupts, don't set DSISR (Data Storage Interrupt Status Register) to a useful value. All ISA versions from v2.03 through v3.1 specify that the Data Segment Interrupt sets DSISR "to an undefined value". As far as I can see there's no mention of SLB faults setting DSISR in any BookIV content either.

This manifests as accesses that should be a read being incorrectly reported as writes, for example, using the xmon "dump" command:

0:mon> d 0x5deadbeef0000000 5deadbeef0000000 [359526.415354][ C6] BUG: Unable to handle kernel data access on write at 0x5deadbeef0000000 [359526.415611][ C6] Faulting instruction address: 0xc00000000010a300 cpu 0x6: Vector: 380 (Data SLB Access) at [c00000000ffbf400] pc: c00000000010a300: mread+0x90/0x190

If we disassemble the PC, we see a load instruction:

0:mon> di c00000000010a300 c00000000010a300 89490000 lbz r10,0(r9)

We can also see in exceptions-64s.S that the data_access_slb block doesn't set IDSISR=1, which means it doesn't load DSISR into pt_regs. So the value we're using to determine if the fault is a read/write is some stale value in pt_regs from a previous page fault.

Rework the printing logic to separate the SLB fault case out, and only print read/write in the cases where we can determine it.

The result looks like eg:

0:mon> d 0x5deadbeef0000000 5deadbeef0000000 [ 721.779525][ C6] BUG: Unable to handle kernel data access at 0x5deadbeef0000000 [ 721.779697][ C6] Faulting instruction address: 0xc00000000014cbe0 cpu 0x6: Vector: 380 (Data SLB Access) at [c00000000ffbf390]

0:mon> d 0 0000000000000000 [ 742.793242][ C6] BUG: Kernel NULL pointer dereference at 0x00000000 [ 742.793316][ C6] Faulting instruction address: 0xc00000000014cbe0 cpu 0x6: Vector: 380 (Data SLB Access) at [c00000000ffbf390]

Severity

5.5 (Medium)


                  
                    CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

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{
  "affected": [],
  "aliases": [
    "CVE-2022-49214"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-476"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2025-02-26T07:00:58Z",
    "severity": "MODERATE"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\npowerpc/64s: Don\u0027t use DSISR for SLB faults\n\nSince commit 46ddcb3950a2 (\"powerpc/mm: Show if a bad page fault on data\nis read or write.\") we use page_fault_is_write(regs-\u003edsisr) in\n__bad_page_fault() to determine if the fault is for a read or write, and\nchange the message printed accordingly.\n\nBut SLB faults, aka Data Segment Interrupts, don\u0027t set DSISR (Data\nStorage Interrupt Status Register) to a useful value. All ISA versions\nfrom v2.03 through v3.1 specify that the Data Segment Interrupt sets\nDSISR \"to an undefined value\". As far as I can see there\u0027s no mention of\nSLB faults setting DSISR in any BookIV content either.\n\nThis manifests as accesses that should be a read being incorrectly\nreported as writes, for example, using the xmon \"dump\" command:\n\n  0:mon\u003e d 0x5deadbeef0000000\n  5deadbeef0000000\n  [359526.415354][    C6] BUG: Unable to handle kernel data access on write at 0x5deadbeef0000000\n  [359526.415611][    C6] Faulting instruction address: 0xc00000000010a300\n  cpu 0x6: Vector: 380 (Data SLB Access) at [c00000000ffbf400]\n      pc: c00000000010a300: mread+0x90/0x190\n\nIf we disassemble the PC, we see a load instruction:\n\n  0:mon\u003e di c00000000010a300\n  c00000000010a300 89490000      lbz     r10,0(r9)\n\nWe can also see in exceptions-64s.S that the data_access_slb block\ndoesn\u0027t set IDSISR=1, which means it doesn\u0027t load DSISR into pt_regs. So\nthe value we\u0027re using to determine if the fault is a read/write is some\nstale value in pt_regs from a previous page fault.\n\nRework the printing logic to separate the SLB fault case out, and only\nprint read/write in the cases where we can determine it.\n\nThe result looks like eg:\n\n  0:mon\u003e d 0x5deadbeef0000000\n  5deadbeef0000000\n  [  721.779525][    C6] BUG: Unable to handle kernel data access at 0x5deadbeef0000000\n  [  721.779697][    C6] Faulting instruction address: 0xc00000000014cbe0\n  cpu 0x6: Vector: 380 (Data SLB Access) at [c00000000ffbf390]\n\n  0:mon\u003e d 0\n  0000000000000000\n  [  742.793242][    C6] BUG: Kernel NULL pointer dereference at 0x00000000\n  [  742.793316][    C6] Faulting instruction address: 0xc00000000014cbe0\n  cpu 0x6: Vector: 380 (Data SLB Access) at [c00000000ffbf390]",
  "id": "GHSA-8jrg-738q-v5mw",
  "modified": "2025-09-22T21:30:15Z",
  "published": "2025-09-22T21:30:15Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2022-49214"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/093449bb182db885dae816d62874cccab7a4c42a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/4a852ff9b7bea9c640540e2c1bc70bd3ba455d61"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a3dae36d632b2cf6eb20314273e512a96cb43c9a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d4679ac8ea2e5078704aa1c026db36580cc1bf9a"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2022-49214 (GCVE-0-2022-49214)

Vulnerability from cvelistv5 – Published: 2025-02-26 01:55 – Updated: 2026-05-11 18:55

Title

powerpc/64s: Don't use DSISR for SLB faults

Summary

In the Linux kernel, the following vulnerability has been resolved: powerpc/64s: Don't use DSISR for SLB faults Since commit 46ddcb3950a2 ("powerpc/mm: Show if a bad page fault on data is read or write.") we use page_fault_is_write(regs->dsisr) in __bad_page_fault() to determine if the fault is for a read or write, and change the message printed accordingly. But SLB faults, aka Data Segment Interrupts, don't set DSISR (Data Storage Interrupt Status Register) to a useful value. All ISA versions from v2.03 through v3.1 specify that the Data Segment Interrupt sets DSISR "to an undefined value". As far as I can see there's no mention of SLB faults setting DSISR in any BookIV content either. This manifests as accesses that should be a read being incorrectly reported as writes, for example, using the xmon "dump" command: 0:mon> d 0x5deadbeef0000000 5deadbeef0000000 [359526.415354][ C6] BUG: Unable to handle kernel data access on write at 0x5deadbeef0000000 [359526.415611][ C6] Faulting instruction address: 0xc00000000010a300 cpu 0x6: Vector: 380 (Data SLB Access) at [c00000000ffbf400] pc: c00000000010a300: mread+0x90/0x190 If we disassemble the PC, we see a load instruction: 0:mon> di c00000000010a300 c00000000010a300 89490000 lbz r10,0(r9) We can also see in exceptions-64s.S that the data_access_slb block doesn't set IDSISR=1, which means it doesn't load DSISR into pt_regs. So the value we're using to determine if the fault is a read/write is some stale value in pt_regs from a previous page fault. Rework the printing logic to separate the SLB fault case out, and only print read/write in the cases where we can determine it. The result looks like eg: 0:mon> d 0x5deadbeef0000000 5deadbeef0000000 [ 721.779525][ C6] BUG: Unable to handle kernel data access at 0x5deadbeef0000000 [ 721.779697][ C6] Faulting instruction address: 0xc00000000014cbe0 cpu 0x6: Vector: 380 (Data SLB Access) at [c00000000ffbf390] 0:mon> d 0 0000000000000000 [ 742.793242][ C6] BUG: Kernel NULL pointer dereference at 0x00000000 [ 742.793316][ C6] Faulting instruction address: 0xc00000000014cbe0 cpu 0x6: Vector: 380 (Data SLB Access) at [c00000000ffbf390]

Severity

No CVSS data available.

Assigner

Linux mitre root

References

4 references

URL	Tags
https://git.kernel.org/stable/c/4a852ff9b7bea9c64…
https://git.kernel.org/stable/c/a3dae36d632b2cf6e…
https://git.kernel.org/stable/c/093449bb182db885d…
https://git.kernel.org/stable/c/d4679ac8ea2e50787…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 46ddcb3950a28c0df4815e8dbb8d4b91d5d9f22d , < 4a852ff9b7bea9c640540e2c1bc70bd3ba455d61 (git) Affected: 46ddcb3950a28c0df4815e8dbb8d4b91d5d9f22d , < a3dae36d632b2cf6eb20314273e512a96cb43c9a (git) Affected: 46ddcb3950a28c0df4815e8dbb8d4b91d5d9f22d , < 093449bb182db885dae816d62874cccab7a4c42a (git) Affected: 46ddcb3950a28c0df4815e8dbb8d4b91d5d9f22d , < d4679ac8ea2e5078704aa1c026db36580cc1bf9a (git)
Linux	Linux	Affected: 5.5 Unaffected: 0 , < 5.5 (semver) Unaffected: 5.15.33 , ≤ 5.15.* (semver) Unaffected: 5.16.19 , ≤ 5.16.* (semver) Unaffected: 5.17.2 , ≤ 5.17.* (semver) Unaffected: 5.18 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "arch/powerpc/mm/fault.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "4a852ff9b7bea9c640540e2c1bc70bd3ba455d61",
              "status": "affected",
              "version": "46ddcb3950a28c0df4815e8dbb8d4b91d5d9f22d",
              "versionType": "git"
            },
            {
              "lessThan": "a3dae36d632b2cf6eb20314273e512a96cb43c9a",
              "status": "affected",
              "version": "46ddcb3950a28c0df4815e8dbb8d4b91d5d9f22d",
              "versionType": "git"
            },
            {
              "lessThan": "093449bb182db885dae816d62874cccab7a4c42a",
              "status": "affected",
              "version": "46ddcb3950a28c0df4815e8dbb8d4b91d5d9f22d",
              "versionType": "git"
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              "status": "affected",
              "version": "46ddcb3950a28c0df4815e8dbb8d4b91d5d9f22d",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "arch/powerpc/mm/fault.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.5"
            },
            {
              "lessThan": "5.5",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
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              "status": "unaffected",
              "version": "5.15.33",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.16.*",
              "status": "unaffected",
              "version": "5.16.19",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.17.*",
              "status": "unaffected",
              "version": "5.17.2",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "5.18",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.15.33",
                  "versionStartIncluding": "5.5",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                  "versionStartIncluding": "5.5",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                  "vulnerable": true
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              "negate": false,
              "operator": "OR"
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          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\npowerpc/64s: Don\u0027t use DSISR for SLB faults\n\nSince commit 46ddcb3950a2 (\"powerpc/mm: Show if a bad page fault on data\nis read or write.\") we use page_fault_is_write(regs-\u003edsisr) in\n__bad_page_fault() to determine if the fault is for a read or write, and\nchange the message printed accordingly.\n\nBut SLB faults, aka Data Segment Interrupts, don\u0027t set DSISR (Data\nStorage Interrupt Status Register) to a useful value. All ISA versions\nfrom v2.03 through v3.1 specify that the Data Segment Interrupt sets\nDSISR \"to an undefined value\". As far as I can see there\u0027s no mention of\nSLB faults setting DSISR in any BookIV content either.\n\nThis manifests as accesses that should be a read being incorrectly\nreported as writes, for example, using the xmon \"dump\" command:\n\n  0:mon\u003e d 0x5deadbeef0000000\n  5deadbeef0000000\n  [359526.415354][    C6] BUG: Unable to handle kernel data access on write at 0x5deadbeef0000000\n  [359526.415611][    C6] Faulting instruction address: 0xc00000000010a300\n  cpu 0x6: Vector: 380 (Data SLB Access) at [c00000000ffbf400]\n      pc: c00000000010a300: mread+0x90/0x190\n\nIf we disassemble the PC, we see a load instruction:\n\n  0:mon\u003e di c00000000010a300\n  c00000000010a300 89490000      lbz     r10,0(r9)\n\nWe can also see in exceptions-64s.S that the data_access_slb block\ndoesn\u0027t set IDSISR=1, which means it doesn\u0027t load DSISR into pt_regs. So\nthe value we\u0027re using to determine if the fault is a read/write is some\nstale value in pt_regs from a previous page fault.\n\nRework the printing logic to separate the SLB fault case out, and only\nprint read/write in the cases where we can determine it.\n\nThe result looks like eg:\n\n  0:mon\u003e d 0x5deadbeef0000000\n  5deadbeef0000000\n  [  721.779525][    C6] BUG: Unable to handle kernel data access at 0x5deadbeef0000000\n  [  721.779697][    C6] Faulting instruction address: 0xc00000000014cbe0\n  cpu 0x6: Vector: 380 (Data SLB Access) at [c00000000ffbf390]\n\n  0:mon\u003e d 0\n  0000000000000000\n  [  742.793242][    C6] BUG: Kernel NULL pointer dereference at 0x00000000\n  [  742.793316][    C6] Faulting instruction address: 0xc00000000014cbe0\n  cpu 0x6: Vector: 380 (Data SLB Access) at [c00000000ffbf390]"
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-11T18:55:21.234Z",
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        },
        {
          "url": "https://git.kernel.org/stable/c/d4679ac8ea2e5078704aa1c026db36580cc1bf9a"
        }
      ],
      "title": "powerpc/64s: Don\u0027t use DSISR for SLB faults",
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    "assignerShortName": "Linux",
    "cveId": "CVE-2022-49214",
    "datePublished": "2025-02-26T01:55:49.677Z",
    "dateReserved": "2025-02-26T01:49:39.292Z",
    "dateUpdated": "2026-05-11T18:55:21.234Z",
    "state": "PUBLISHED"
  },
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}

Sightings

Author	Source	Type	Date	Other

Nomenclature

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Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
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Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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GHSA-8JRG-738Q-V5MW

CVE-2022-49214 (GCVE-0-2022-49214)

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