Copyright © 2012 Red Hat, Inc. All rights reserved. Moderate 2026-08-28T00:00:00 kernel: perf sched: Fix register_pid() overflow, strcpy, and BUG_ON 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H CWE-787

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.

A flaw was found in the Linux kernel's `perf sched` subsystem. Multiple vulnerabilities exist within the `register_pid()` function when processing untrusted performance data. These include an integer overflow that can lead to out-of-bounds memory writes and a heap buffer overflow due to improper string handling. Additionally, allocation failures are not handled gracefully, which can result in a denial of service (DoS) by terminating the process. An attacker could potentially exploit these issues to cause memory corruption, leading to arbitrary code execution or system instability.

Red Hat Enterprise Linux 10 Not affected kernel Red Hat Enterprise Linux 6 Not affected kernel Red Hat Enterprise Linux 7 Not affected kernel Red Hat Enterprise Linux 7 Not affected kernel-rt Red Hat Enterprise Linux 8 Not affected kernel Red Hat Enterprise Linux 8 Not affected kernel-rt Red Hat Enterprise Linux 9 Not affected kernel Red Hat Enterprise Linux 9 Not affected kernel-rt https://www.cve.org/CVERecord?id=CVE-2026-80671 https://nvd.nist.gov/vuln/detail/CVE-2026-80671 https://lore.kernel.org/linux-cve-announce/2026082848-CVE-2026-80671-e54e@gregkh/T