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CVE-2025-38233 (GCVE-0-2025-38233)

Vulnerability from cvelistv5 – Published: 2025-07-04 13:37 – Updated: 2026-08-05 12:00
VLAI
Title
powerpc64/ftrace: fix clobbered r15 during livepatching
Summary
In the Linux kernel, the following vulnerability has been resolved: powerpc64/ftrace: fix clobbered r15 during livepatching While r15 is clobbered always with PPC_FTRACE_OUT_OF_LINE, it is not restored in livepatch sequence leading to not so obvious fails like below: BUG: Unable to handle kernel data access on write at 0xc0000000000f9078 Faulting instruction address: 0xc0000000018ff958 Oops: Kernel access of bad area, sig: 11 [#1] ... NIP: c0000000018ff958 LR: c0000000018ff930 CTR: c0000000009c0790 REGS: c00000005f2e7790 TRAP: 0300 Tainted: G K (6.14.0+) MSR: 8000000000009033 <SF,EE,ME,IR,DR,RI,LE> CR: 2822880b XER: 20040000 CFAR: c0000000008addc0 DAR: c0000000000f9078 DSISR: 0a000000 IRQMASK: 1 GPR00: c0000000018f2584 c00000005f2e7a30 c00000000280a900 c000000017ffa488 GPR04: 0000000000000008 0000000000000000 c0000000018f24fc 000000000000000d GPR08: fffffffffffe0000 000000000000000d 0000000000000000 0000000000008000 GPR12: c0000000009c0790 c000000017ffa480 c00000005f2e7c78 c0000000000f9070 GPR16: c00000005f2e7c90 0000000000000000 0000000000000000 0000000000000000 GPR20: 0000000000000000 c00000005f3efa80 c00000005f2e7c60 c00000005f2e7c88 GPR24: c00000005f2e7c60 0000000000000001 c0000000000f9078 0000000000000000 GPR28: 00007fff97960000 c000000017ffa480 0000000000000000 c0000000000f9078 ... Call Trace: check_heap_object+0x34/0x390 (unreliable) __mutex_unlock_slowpath.isra.0+0xe4/0x230 seq_read_iter+0x430/0xa90 proc_reg_read_iter+0xa4/0x200 vfs_read+0x41c/0x510 ksys_read+0xa4/0x190 system_call_exception+0x1d0/0x440 system_call_vectored_common+0x15c/0x2ec Fix it by restoring r15 always.
Severity
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: eec37961a56aa4f3fe1c33ffd48eec7d1bb0c009 , < a9212bf5ca640232254b31330e86272fe4073bc9 (git)
Affected: eec37961a56aa4f3fe1c33ffd48eec7d1bb0c009 , < cb5b691f8273432297611863ac142e17119279e0 (git)
guessed Create a notification for this product.
Linux Linux Affected: 6.13
Unaffected: 0 , < 6.13 (semver)
Unaffected: 6.15.4 , ≤ 6.15.* (semver)
Unaffected: 6.16 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
Show details on NVD website
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              "value": "AV:L - The corrupted register is consumed by ordinary kernel code paths entered through local syscalls \u2014 the reported oops comes from a plain read(2) on a procfs file (`ksys_read \u2192 vfs_read \u2192 seq_read_iter`). No network protocol handler is inherently involved; reaching the defect requires executing kernel code on the machine.\nAC:L - With a livepatch active, the missing `REST_GPR(15, r1)` executes on 100% of calls to any patched function \u2014 no race, no memory-layout dependency, no timing window. The enabling configuration (ppc64le with `PPC_FTRACE_OUT_OF_LINE` + `LIVEPATCH`) is the default shipping state on enterprise ppc64le distros that offer live patching.\nPR:L - Triggering needs nothing more than invoking a syscall that reaches a livepatched function; the reproducer is an unprivileged `read()` on /proc. The livepatch itself is loaded by the administrator as routine maintenance, not as an attacker step, so the attacker only needs an ordinary local account.\nUI:N - Once a livepatch is applied \u2014 the normal steady state of a live-patched server \u2014 no victim action of any kind is required; the attacker simply calls into a patched function.\nS:U - The clobbered non-volatile register corrupts the kernel\u0027s own execution state within the same security authority; no hypervisor, IOMMU, or sandbox boundary is crossed.\nC:H - The caller chain resumes with r15 silently replaced by a kernel `.text` stub address, so any function using r15 as a pointer, index, or length operates on corrupted state \u2014 on read/usercopy paths (`seq_read_iter`, `check_heap_object` in the reported trace) this can steer kernel memory into a user buffer, and the injected value itself is a live kernel text address that defeats KASLR if it reaches userspace.\nI:H - This is genuine kernel memory corruption with write effect \u2014 the reported failure is a faulting *store* to an address derived from the clobbered register, from inside `__mutex_unlock_slowpath` operating on a corrupt mutex pointer. Corrupting a callee-saved register in arbitrary kernel functions yields uncontrolled writes and corrupted locking/data structures that can be leveraged for control-flow-relevant damage.\nA:H - The demonstrated result is an immediate kernel oops (\"Unable to handle kernel data access on write\", sig 11), and because the corruption recurs on every call to a patched function it is trivially repeatable until the system panics or hangs on corrupted lock state."
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    "dateReserved": "2025-04-16T04:51:23.996Z",
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            "value": "In the Linux kernel, the following vulnerability has been resolved:\n\npowerpc64/ftrace: fix clobbered r15 during livepatching\n\nWhile r15 is clobbered always with PPC_FTRACE_OUT_OF_LINE, it is\nnot restored in livepatch sequence leading to not so obvious fails\nlike below:\n\n  BUG: Unable to handle kernel data access on write at 0xc0000000000f9078\n  Faulting instruction address: 0xc0000000018ff958\n  Oops: Kernel access of bad area, sig: 11 [#1]\n  ...\n  NIP:  c0000000018ff958 LR: c0000000018ff930 CTR: c0000000009c0790\n  REGS: c00000005f2e7790 TRAP: 0300   Tainted: G              K      (6.14.0+)\n  MSR:  8000000000009033 \u003cSF,EE,ME,IR,DR,RI,LE\u003e  CR: 2822880b  XER: 20040000\n  CFAR: c0000000008addc0 DAR: c0000000000f9078 DSISR: 0a000000 IRQMASK: 1\n  GPR00: c0000000018f2584 c00000005f2e7a30 c00000000280a900 c000000017ffa488\n  GPR04: 0000000000000008 0000000000000000 c0000000018f24fc 000000000000000d\n  GPR08: fffffffffffe0000 000000000000000d 0000000000000000 0000000000008000\n  GPR12: c0000000009c0790 c000000017ffa480 c00000005f2e7c78 c0000000000f9070\n  GPR16: c00000005f2e7c90 0000000000000000 0000000000000000 0000000000000000\n  GPR20: 0000000000000000 c00000005f3efa80 c00000005f2e7c60 c00000005f2e7c88\n  GPR24: c00000005f2e7c60 0000000000000001 c0000000000f9078 0000000000000000\n  GPR28: 00007fff97960000 c000000017ffa480 0000000000000000 c0000000000f9078\n  ...\n  Call Trace:\n    check_heap_object+0x34/0x390 (unreliable)\n  __mutex_unlock_slowpath.isra.0+0xe4/0x230\n  seq_read_iter+0x430/0xa90\n  proc_reg_read_iter+0xa4/0x200\n  vfs_read+0x41c/0x510\n  ksys_read+0xa4/0x190\n  system_call_exception+0x1d0/0x440\n  system_call_vectored_common+0x15c/0x2ec\n\nFix it by restoring r15 always."
          },
          {
            "lang": "es",
            "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: powerpc64/ftrace: arregla el r15 da\u00f1ado durante el parche en vivo Si bien r15 siempre se da\u00f1a con PPC_FTRACE_OUT_OF_LINE, no se restaura en la secuencia de parche en vivo, lo que lleva a fallas no tan obvias como las siguientes: ERROR: No se puede manejar el acceso a los datos del kernel en escritura en 0xc0000000000f9078 Direcci\u00f3n de instrucci\u00f3n err\u00f3nea: 0xc0000000018ff958 Oops: Acceso al kernel de \u00e1rea defectuosa, sig: 11 [#1] ... NIP: c0000000018ff958 LR: c0000000018ff930 CTR: c0000000009c0790 REGS: c00000005f2e7790 TRAP: 0300 Tainted: GK (6.14.0+) MSR: 8000000000009033  CR: 2822880b XER: 20040000 CFAR: c0000000008addc0 DAR: c0000000000f9078 DSISR: 0a000000 IRQMASK: 1 GPR00: c0000000018f2584 c00000005f2e7a30 c00000000280a900 c000000017ffa488 GPR04: 00000000000000008 00000000000000000 c0000000018f24fc 000000000000000d GPR08: fffffffffffe0000 000000000000000d 0000000000000000 00000000000008000 GPR12: c0000000009c0790 c000000017ffa480 c00000005f2e7c78 c000000000f9070 GPR16: c00000005f2e7c90 000000000000000 000000000000000 000000000000000 GPR20: 000000000000000 c00000005f3efa80 c00000005f2e7c60 c00000005f2e7c88 GPR24: c00000005f2e7c60 0000000000000001 c00000000000f9078 0000000000000000 GPR28: 00007fff97960000 c000000017ffa480 0000000000000000 c0000000000f9078 ... Rastreo de llamadas: check_heap_object+0x34/0x390 (no confiable) __mutex_unlock_slowpath.isra.0+0xe4/0x230 seq_read_iter+0x430/0xa90 proc_reg_read_iter+0xa4/0x200 vfs_read+0x41c/0x510 ksys_read+0xa4/0x190 system_call_exception+0x1d0/0x440 system_call_vectored_common+0x15c/0x2ec Arr\u00e9glelo restaurando r15 siempre."
          }
        ],
        "id": "CVE-2025-38233",
        "lastModified": "2026-07-30T06:23:02.743",
        "metrics": {
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              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "LOCAL",
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                "baseScore": 7.8,
                "baseSeverity": "HIGH",
                "confidentialityImpact": "HIGH",
                "integrityImpact": "HIGH",
                "privilegesRequired": "LOW",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
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            "tags": [
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        "vulnStatus": "Modified",
        "weaknesses": [
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                "lang": "en",
                "value": "NVD-CWE-noinfo"
              }
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            "source": "nvd@nist.gov",
            "type": "Primary"
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    },
    "redhat_vex": {
      "aggregate_severity": "None",
      "current_release_date": "2026-06-30T10:21:31+00:00",
      "cve": "CVE-2025-38233",
      "id": "CVE-2025-38233",
      "initial_release_date": "2025-07-04T00:00:00+00:00",
      "product_status:known_not_affected": "274",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: powerpc64/ftrace: fix clobbered r15 during livepatching",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-38233.json",
      "version": "3"
    }
  }
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • 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.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • 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.


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