CVE-2026-98552 (GCVE-0-2026-98552)

Vulnerability from cvelistv5 – Published: 2026-10-18 15:18 – Updated: 2026-10-19 09:21
VLAI
Title
perf/core: Fix a refcount leak in attach_perf_ctx_data()
Summary
In the Linux kernel, the following vulnerability has been resolved: perf/core: Fix a refcount leak in attach_perf_ctx_data() The attach_perf_ctx_data() can race on global and !global cases. The global case is protected by global_ctx_data_rwsem and shares a single reference count using perf_ctx_data.global field. But when it races with !global case, it may miss to set the global field and result in a reference count leak. CPU1 CPU2 ---------------------------------------------------------------- attach_task_ctx_data(.global=1) attach_task_ctx_data(.global=0) cd1 = alloc_perf_ctx_data(); cd2 = alloc_perf_ctx_data(); // { .global = 0, .refcount = 1 }; try_cmpxchg(); // success, // task->perf_ctx_data = cd2 try_cmpxhg(); // fail; old = cd2 refcount_inc_not_zero(&old->refcount); // success // old.refcount = 2 free_perf_ctx_data(cd1); Then later detach_global_ctx_data() will see the data but it's not marked as global, so it won't call detach_task_ctx_data().
Severity
No CVSS data available.
Assigner
Linux CNA under the mitre root
CNA scorecard D 53/100 over 7064 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 506e64e710ff9573fd2b86686528762b7901b5e4 , < 23250517cd475367653f1e99396967f54c6f1b7c (git)
Affected: 506e64e710ff9573fd2b86686528762b7901b5e4 , < 5286d4eb5cd7e10d7d93c3cc596e18bc8ad80f72 (git)
Affected: 506e64e710ff9573fd2b86686528762b7901b5e4 , < cca4980630b3c7a85f53cb43c6018184ce5d4e37 (git)
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Linux Linux Affected: 6.15
Unaffected: 0 , < 6.15 (semver)
Unaffected: 6.18.55 , ≤ 6.18.* (semver)
Unaffected: 7.2.9 , ≤ 7.2.* (semver)
Unaffected: 7.3 , ≤ * (original_commit_for_fix)
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{
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nperf/core: Fix a refcount leak in attach_perf_ctx_data()\n\nThe attach_perf_ctx_data() can race on global and !global cases.  The\nglobal case is protected by global_ctx_data_rwsem and shares a single\nreference count using perf_ctx_data.global field.\n\nBut when it races with !global case, it may miss to set the global field\nand result in a reference count leak.\n\n CPU1                                  CPU2\n ----------------------------------------------------------------\n attach_task_ctx_data(.global=1)       attach_task_ctx_data(.global=0)\n   cd1 = alloc_perf_ctx_data();          cd2 = alloc_perf_ctx_data();\n                                         //    { .global = 0, .refcount = 1 };\n\n                                         try_cmpxchg(); // success,\n                                         // task-\u003eperf_ctx_data = cd2\n   try_cmpxhg(); // fail; old = cd2\n   refcount_inc_not_zero(\u0026old-\u003erefcount); // success\n     // old.refcount = 2\n   free_perf_ctx_data(cd1);\n\nThen later detach_global_ctx_data() will see the data but it\u0027s not\nmarked as global, so it won\u0027t call detach_task_ctx_data()."
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    "datePublished": "2026-10-18T15:18:19.810Z",
    "dateReserved": "2026-09-25T10:25:14.356Z",
    "dateUpdated": "2026-10-19T09:21:35.261Z",
    "state": "PUBLISHED"
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        "descriptions": [
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            "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nperf/core: Fix a refcount leak in attach_perf_ctx_data()\n\nThe attach_perf_ctx_data() can race on global and !global cases.  The\nglobal case is protected by global_ctx_data_rwsem and shares a single\nreference count using perf_ctx_data.global field.\n\nBut when it races with !global case, it may miss to set the global field\nand result in a reference count leak.\n\n CPU1                                  CPU2\n ----------------------------------------------------------------\n attach_task_ctx_data(.global=1)       attach_task_ctx_data(.global=0)\n   cd1 = alloc_perf_ctx_data();          cd2 = alloc_perf_ctx_data();\n                                         //    { .global = 0, .refcount = 1 };\n\n                                         try_cmpxchg(); // success,\n                                         // task-\u003eperf_ctx_data = cd2\n   try_cmpxhg(); // fail; old = cd2\n   refcount_inc_not_zero(\u0026old-\u003erefcount); // success\n     // old.refcount = 2\n   free_perf_ctx_data(cd1);\n\nThen later detach_global_ctx_data() will see the data but it\u0027s not\nmarked as global, so it won\u0027t call detach_task_ctx_data()."
          }
        ],
        "id": "CVE-2026-98552",
        "lastModified": "2026-10-19T10:19:11.487",
        "metrics": {},
        "published": "2026-10-18T16:17:07.267",
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}



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