CVE-2026-80671

CRITICAL
9.3CVSS v3
CVSS v2
0.16% EPSS (exploit probability)
CWE

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.

CVSS v3 vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Affected routers (0)

No routers currently mapped to this CVE in our database.

External references