CVE-2026-80671 (GCVE-0-2026-80671)
Vulnerability from cvelistv5
Published
2026-08-28 06:49
Modified
2026-08-29 06:21
Severity ?
VLAI Severity ?
EPSS score ?
Summary
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.
References
Impacted products
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"tools/perf/builtin-sched.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "652cea73b7b7b7c622a2be670e44e3c499c6d49f",
"status": "affected",
"version": "ec156764d424dd67283c2cd5e9f6f1b8388364ac",
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},
{
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"versionType": "git"
},
{
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"status": "affected",
"version": "ec156764d424dd67283c2cd5e9f6f1b8388364ac",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"tools/perf/builtin-sched.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "2.6.32"
},
{
"lessThan": "2.6.32",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.40",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.5",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.18.40",
"versionStartIncluding": "2.6.32",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.1.5",
"versionStartIncluding": "2.6.32",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.2",
"versionStartIncluding": "2.6.32",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "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."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 9.3,
"baseSeverity": "CRITICAL",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H",
"version": "3.1"
},
"scenarios": [
{
"lang": "en",
"value": "AV:L - The flaw is in userspace perf\u0027s builtin-sched.c reached only when a local user runs perf sched replay or perf sched latency against a crafted perf.data file via perf_session__process_events; it is not triggered by remote network packets, kernel syscalls, or in-kernel sched code.\nAC:L - The attacker fully controls untrusted perf.data sched_switch/sched_wakeup fields (prev_pid, next_pid, prev_comm, next_comm); large PIDs and overlong comm strings deterministically hit the integer-overflow realloc path or strcpy heap overflow without races or victim-specific memory layout.\nPR:N - In the malicious-trace threat model an external party needs no account or privileges on the victim host\u2014they only supply a crafted perf.data file for a developer, support engineer, or CI job to analyze with perf sched replay/latency.\nUI:N - Once a trace is submitted to triage or CI, perf sched replay/latency parses perf.data non-interactively through perf_sched__read_events without further per-event operator actions beyond automated invocation of the perf command on the supplied file.\nS:C - Malicious sched metadata embedded in an externally supplied perf.data crosses from the untrusted reporter/artifact domain into the analyst or CI host security authority when perf parses that file, matching the kernel CNA untrusted-artifact model used for crafted filesystem images.\nC:H - Integer-overflow-driven out-of-bounds writes into the pid_to_task table and strcpy heap overflow past task_desc.comm[20] corrupt adjacent heap objects and can disclose process memory beyond a few bounded bytes.\nI:H - Attacker-controlled overflows corrupt task_desc function pointers and heap metadata (including the atoms pointer), providing controllable userspace memory corruption suitable for arbitrary write and code execution in the perf process.\nA:H - Pre-fix BUG_ON paths abort the perf process on allocation failure, and the heap out-of-bounds writes reliably crash or hang perf during register_pid() while parsing malicious perf.data."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-29T06:21:57.947Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/652cea73b7b7b7c622a2be670e44e3c499c6d49f"
},
{
"url": "https://git.kernel.org/stable/c/5ea1dcc9418c4e06ce29ed5170596f497ba86872"
},
{
"url": "https://git.kernel.org/stable/c/5949d339f5ec98752d56dcd4e36f619a59d513a5"
}
],
"title": "perf sched: Fix register_pid() overflow, strcpy, and BUG_ON",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-80671",
"datePublished": "2026-08-28T06:49:11.744Z",
"dateReserved": "2026-08-26T14:34:25.782Z",
"dateUpdated": "2026-08-29T06:21:57.947Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
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