{"id":"CVE-2026-80671","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-80671","summary":"perf sched: Fix register_pid() overflow, strcpy, and BUG_ON","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nperf sched: Fix register_pid() overflow, strcpy, and BUG_ON\n\nregister_pid() has several issues when processing untrusted perf.data:\n\n1. Integer overflow: (pid + 1) * sizeof(struct task_desc *) can wrap\n   to a small value on 32-bit systems when pid is large (e.g.\n   0x40000000), causing realloc to return a tiny buffer followed by\n   out-of-bounds writes in the initialization loop.\n\n2. Heap buffer overflow: strcpy(task->comm, comm) copies the\n   untrusted comm string into a fixed 20-byte COMM_LEN buffer with\n   no length check.\n\n3. BUG_ON on allocation failure: perf.data is untrusted input, so\n   allocation failures should be handled gracefully rather than\n   killing the process.\n\n4. Realloc of sched->tasks assigned directly back, leaking the old\n   pointer on failure; nr_tasks incremented before the realloc,\n   leaving corrupted state on failure.\n\nCap pid at PID_MAX_LIMIT (4194304, matching the kernel's maximum\non 64-bit), replace strcpy with strlcpy, guard against NULL comm,\nreplace BUG_ON with NULL returns using safe realloc patterns, and\nadd NULL checks in callers that dereference the result.","published":"2026-08-28T06:49:11.744Z","modified":"2026-08-30T03:48:22.920935767Z","cvss":{"score":9.3,"severity":"CRITICAL","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"Linux","name":"Kernel","fixedVersion":"6.18.40"}],"fix":null,"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/5949d339f5ec98752d56dcd4e36f619a59d513a5"},{"type":"WEB","url":"https://git.kernel.org/stable/c/5ea1dcc9418c4e06ce29ed5170596f497ba86872"},{"type":"WEB","url":"https://git.kernel.org/stable/c/652cea73b7b7b7c622a2be670e44e3c499c6d49f"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80671.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-80671"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-30T03:48:22.920935767Z"}}