CVE-2026-80671

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

perf sched: Fix registerpid() overflow, strcpy, and BUGON

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.

1. Heap buffer overflow: strcpy(task->comm, comm) copies the

   untrusted comm string into a fixed 20-byte COMM_LEN buffer with

   no length check.

1. BUG_ON on allocation failure: perf.data is untrusted input, so

   allocation failures should be handled gracefully rather than

   killing the process.

1. 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 PIDMAXLIMIT (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.