# CVE-2026-80671

## Summary

- **CVE ID:** CVE-2026-80671
- **Severity:** CRITICAL
- **CVSS Score:** 9.3 (CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H)
- **CWE:** N/A
- **Published:** Aug 28, 2026
- **Last Modified:** Sep 14, 2026

## 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.

## Affected Products

- Linux — Linux (ec156764d424dd67283c2cd5e9f6f1b8388364ac)
- Linux — Linux (2.6.32)
- Linux — Linux (0)
- Linux — Linux (6.18.40)
- Linux — Linux (7.1.5)
- Linux — Linux (7.2)
- Linux — Linux (5.10.270)
- Linux — Linux (5.15.221)
- Linux — Linux (6.1.188)
- Linux — Linux (6.6.157)
- Linux — Linux (6.12.110)

## References

- [CNA](https://git.kernel.org/stable/c/652cea73b7b7b7c622a2be670e44e3c499c6d49f)
- [CNA](https://git.kernel.org/stable/c/5ea1dcc9418c4e06ce29ed5170596f497ba86872)
- [CNA](https://git.kernel.org/stable/c/5949d339f5ec98752d56dcd4e36f619a59d513a5)
- [CNA](https://git.kernel.org/stable/c/344e59fc4f2cba6dc04ce5e2a77388645d4ca834)
- [CNA](https://git.kernel.org/stable/c/22263d241bad753217d545f8085b7ead52e2873b)
- [CNA](https://git.kernel.org/stable/c/2003918e13f43cf6c5698be3cc9aa3657dd676a8)
- [CNA](https://git.kernel.org/stable/c/29639f00bfa49da7904ba0a499e0da7a0e5d735e)
- [CNA](https://git.kernel.org/stable/c/261d2b5f4afa0570ca906e553c93811c5abe4590)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.16%
- **EPSS Percentile:** 5.4

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-18._