FKIE_CVE-2023-54267

Vulnerability from fkie_nvd - Published: 2025-12-30 13:16 - Updated: 2025-12-30 13:16
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: powerpc/pseries: Rework lppaca_shared_proc() to avoid DEBUG_PREEMPT lppaca_shared_proc() takes a pointer to the lppaca which is typically accessed through get_lppaca(). With DEBUG_PREEMPT enabled, this leads to checking if preemption is enabled, for example: BUG: using smp_processor_id() in preemptible [00000000] code: grep/10693 caller is lparcfg_data+0x408/0x19a0 CPU: 4 PID: 10693 Comm: grep Not tainted 6.5.0-rc3 #2 Call Trace: dump_stack_lvl+0x154/0x200 (unreliable) check_preemption_disabled+0x214/0x220 lparcfg_data+0x408/0x19a0 ... This isn't actually a problem however, as it does not matter which lppaca is accessed, the shared proc state will be the same. vcpudispatch_stats_procfs_init() already works around this by disabling preemption, but the lparcfg code does not, erroring any time /proc/powerpc/lparcfg is accessed with DEBUG_PREEMPT enabled. Instead of disabling preemption on the caller side, rework lppaca_shared_proc() to not take a pointer and instead directly access the lppaca, bypassing any potential preemption checks. [mpe: Rework to avoid needing a definition in paca.h and lppaca.h]
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/2935443dc9c28499223d8c881474259e4b998f2a
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/3c5e8e666794d7dde6d14ea846c6c04f2bb34900
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/4c8568cf4c45b415854195c8832b557cdefba57a
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/953c54dfdc5d3eb7243ed902b50acb5ea1db4355
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/eac030b22ea12cdfcbb2e941c21c03964403c63f
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/f45ee5c074013a0fbfce77a5af5efddb01f5d4f4
Impacted products
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{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\npowerpc/pseries: Rework lppaca_shared_proc() to avoid DEBUG_PREEMPT\n\nlppaca_shared_proc() takes a pointer to the lppaca which is typically\naccessed through get_lppaca().  With DEBUG_PREEMPT enabled, this leads\nto checking if preemption is enabled, for example:\n\n  BUG: using smp_processor_id() in preemptible [00000000] code: grep/10693\n  caller is lparcfg_data+0x408/0x19a0\n  CPU: 4 PID: 10693 Comm: grep Not tainted 6.5.0-rc3 #2\n  Call Trace:\n    dump_stack_lvl+0x154/0x200 (unreliable)\n    check_preemption_disabled+0x214/0x220\n    lparcfg_data+0x408/0x19a0\n    ...\n\nThis isn\u0027t actually a problem however, as it does not matter which\nlppaca is accessed, the shared proc state will be the same.\nvcpudispatch_stats_procfs_init() already works around this by disabling\npreemption, but the lparcfg code does not, erroring any time\n/proc/powerpc/lparcfg is accessed with DEBUG_PREEMPT enabled.\n\nInstead of disabling preemption on the caller side, rework\nlppaca_shared_proc() to not take a pointer and instead directly access\nthe lppaca, bypassing any potential preemption checks.\n\n[mpe: Rework to avoid needing a definition in paca.h and lppaca.h]"
    }
  ],
  "id": "CVE-2023-54267",
  "lastModified": "2025-12-30T13:16:15.517",
  "metrics": {},
  "published": "2025-12-30T13:16:15.517",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/2935443dc9c28499223d8c881474259e4b998f2a"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/3c5e8e666794d7dde6d14ea846c6c04f2bb34900"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/4c8568cf4c45b415854195c8832b557cdefba57a"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/953c54dfdc5d3eb7243ed902b50acb5ea1db4355"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/eac030b22ea12cdfcbb2e941c21c03964403c63f"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/f45ee5c074013a0fbfce77a5af5efddb01f5d4f4"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}


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