GHSA-98VX-8R93-84HF
Vulnerability from github – Published: 2026-08-28 09:31 – Updated: 2026-08-29 09:30In 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:
-
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.
-
Heap buffer overflow: strcpy(task->comm, comm) copies the untrusted comm string into a fixed 20-byte COMM_LEN buffer with no length check.
-
BUG_ON on allocation failure: perf.data is untrusted input, so allocation failures should be handled gracefully rather than killing the process.
-
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": [],
"aliases": [
"CVE-2026-80671"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-08-28T08:16:52Z",
"severity": "CRITICAL"
},
"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-\u003ecomm, 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-\u003etasks 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\u0027s 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.",
"id": "GHSA-98vx-8r93-84hf",
"modified": "2026-08-29T09:30:27Z",
"published": "2026-08-28T09:31:48Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-80671"
},
{
"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"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
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- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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