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

perf sched: Fix register_pid() overflow, strcpy, and BUG_ON

register_pid() has several issues when processing untrusted perf.data:

1. Integer overflow: (pid + 1) * sizeof(struct task_desc *) can wrap
to a small value on 32-bit systems when pid is large (e.g.
0x40000000), causing realloc to return a tiny buffer followed by
out-of-bounds writes in the initialization loop.

2. Heap buffer overflow: strcpy(task->comm, comm) copies the
untrusted comm string into a fixed 20-byte COMM_LEN buffer with
no length check.

3. BUG_ON on allocation failure: perf.data is untrusted input, so
allocation failures should be handled gracefully rather than
killing the process.

4. Realloc of sched->tasks assigned directly back, leaking the old
pointer on failure; nr_tasks incremented before the realloc,
leaving corrupted state on failure.

Cap pid at PID_MAX_LIMIT (4194304, matching the kernel's maximum
on 64-bit), replace strcpy with strlcpy, guard against NULL comm,
replace BUG_ON with NULL returns using safe realloc patterns, and
add NULL checks in callers that dereference the result.
Advisories
Source ID Title
Debian DLA Debian DLA DLA-4817-1 linux-6.12 security update
Debian DSA Debian DSA DSA-6528-1 linux security update
Ubuntu USN Ubuntu USN USN-8887-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8888-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-8889-1 Linux kernel (OEM) vulnerabilities
Ubuntu USN Ubuntu USN USN-8887-2 Linux kernel (AWS) vulnerabilities
Ubuntu USN Ubuntu USN USN-8888-2 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-8887-3 Linux kernel vulnerabilities
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Mon, 14 Sep 2026 12:30:00 +0000


Mon, 31 Aug 2026 15:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-119
CWE-252
CWE-680
CWE-772

Mon, 31 Aug 2026 12:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-787
References
Metrics threat_severity

None

threat_severity

Moderate


Sat, 29 Aug 2026 06:45:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 9.3, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H'}


Fri, 28 Aug 2026 16:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-119
CWE-252
CWE-680
CWE-772

Fri, 28 Aug 2026 13:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-119
CWE-680

Fri, 28 Aug 2026 10:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-119
CWE-680

Fri, 28 Aug 2026 07:30:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: perf sched: Fix register_pid() overflow, strcpy, and BUG_ON register_pid() has several issues when processing untrusted perf.data: 1. Integer overflow: (pid + 1) * sizeof(struct task_desc *) can wrap to a small value on 32-bit systems when pid is large (e.g. 0x40000000), causing realloc to return a tiny buffer followed by out-of-bounds writes in the initialization loop. 2. Heap buffer overflow: strcpy(task->comm, comm) copies the untrusted comm string into a fixed 20-byte COMM_LEN buffer with no length check. 3. BUG_ON on allocation failure: perf.data is untrusted input, so allocation failures should be handled gracefully rather than killing the process. 4. Realloc of sched->tasks assigned directly back, leaking the old pointer on failure; nr_tasks incremented before the realloc, leaving corrupted state on failure. Cap pid at PID_MAX_LIMIT (4194304, matching the kernel's maximum on 64-bit), replace strcpy with strlcpy, guard against NULL comm, replace BUG_ON with NULL returns using safe realloc patterns, and add NULL checks in callers that dereference the result.
Title perf sched: Fix register_pid() overflow, strcpy, and BUG_ON
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Projects

Sign in to view the affected projects.

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-09-14T11:58:49.345Z

Reserved: 2026-08-26T14:34:25.782Z

Link: CVE-2026-80671

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-28T08:16:52.410

Modified: 2026-09-14T13:18:48.167

Link: CVE-2026-80671

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-08-28T00:00:00Z

Links: CVE-2026-80671 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-08-31T17:00:03Z

Weaknesses