Description
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().
Published: 2026-10-18
Score: 2.5 Low
EPSS: < 1% Very Low
KEV: No
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Remediation

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History

Tue, 20 Oct 2026 20:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-362
CWE-401

Tue, 20 Oct 2026 12:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-911
References
Metrics threat_severity

None

cvssV3_1

{'score': 2.5, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L'}

threat_severity

Low


Sun, 18 Oct 2026 18:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-362
CWE-401

Sun, 18 Oct 2026 15:30:00 +0000

Type Values Removed Values Added
Description 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().
Title perf/core: Fix a refcount leak in attach_perf_ctx_data()
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Subscriptions

Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-10-19T09:21:35.261Z

Reserved: 2026-09-25T10:25:14.356Z

Link: CVE-2026-98552

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-18T16:17:07.267

Modified: 2026-10-19T10:19:11.487

Link: CVE-2026-98552

cve-icon Redhat

Severity : Low

Publid Date: 2026-10-18T00:00:00Z

Links: CVE-2026-98552 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-10-20T20:15:07Z

Weaknesses
  • CWE-911

    Improper Update of Reference Count