CVE-2026-90002 (GCVE-0-2026-90002)
Vulnerability from cvelistv5 – Published: 2026-09-16 10:33 – Updated: 2026-09-16 14:41
VLAI
EPSS
VEX
Title
ftrace: Take trace_array reference before accessing its ftrace_ops
Summary
In the Linux kernel, the following vulnerability has been resolved:
ftrace: Take trace_array reference before accessing its ftrace_ops
The trace instance files set_ftrace_filter and set_ftrace_notrace was
updated to work with specific trace instances (trace_arrays). The issue is
that when these files are opened, there is a small race window where it
will use the ftrace_ops from the inode->private pointer to get a reference
to the trace_array and then take its reference. The problem is that the
ftrace_ops itself could be freed. If the rmdir on the instance happens at
the same time the set_ftrace_filter file is opened, the rmdir could have
also freed the ftrace_ops and referencing it will cause a use-after-free
bug and crash the kernel.
Instead, pass in the trace_array as the file private data (NULL for the
top level instance), and then pass both the trace_array and the ftrace_ops
to the ftrace_regex_open() function. If the trace_array is NULL, then it
just uses the ftrace_ops without the need to take its reference (like
normal). If the ftrace_ops is NULL, that is only the case for the top
level instance and the global_ops can be used.
This allows the trace_array to have its reference incremented before
touching the ftrace_ops that could also be freed when the instance is.
Severity
7.8 (High)
Assigner
References
Impacted products
2 products
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Linux | Linux |
Affected:
591dffdade9f07692a7dd3ed16830ec24e901ece , < 83fd7eca5ab0d3ac3f23bff889175d847e21af06
(git)
Affected: 591dffdade9f07692a7dd3ed16830ec24e901ece , < cee8f286794df916553d8d445eac5c323ec5b0f8 (git) Affected: 591dffdade9f07692a7dd3ed16830ec24e901ece , < 9100191e5acb2e5ea2313f436667bb5fce129f47 (git) |
guessed | |
| Linux | Linux |
Affected:
3.15
Unaffected: 0 , < 3.15 (semver) Unaffected: 6.18.52 , ≤ 6.18.* (semver) Unaffected: 7.2.5 , ≤ 7.2.* (semver) Unaffected: 7.3-rc2 , ≤ * (original_commit_for_fix) |
guessed |
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"include/linux/ftrace.h",
"kernel/trace/ftrace.c",
"kernel/trace/trace.h",
"kernel/trace/trace_functions.c",
"kernel/trace/trace_stack.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "83fd7eca5ab0d3ac3f23bff889175d847e21af06",
"status": "affected",
"version": "591dffdade9f07692a7dd3ed16830ec24e901ece",
"versionType": "git"
},
{
"lessThan": "cee8f286794df916553d8d445eac5c323ec5b0f8",
"status": "affected",
"version": "591dffdade9f07692a7dd3ed16830ec24e901ece",
"versionType": "git"
},
{
"lessThan": "9100191e5acb2e5ea2313f436667bb5fce129f47",
"status": "affected",
"version": "591dffdade9f07692a7dd3ed16830ec24e901ece",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"include/linux/ftrace.h",
"kernel/trace/ftrace.c",
"kernel/trace/trace.h",
"kernel/trace/trace_functions.c",
"kernel/trace/trace_stack.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "3.15"
},
{
"lessThan": "3.15",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.52",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.2.*",
"status": "unaffected",
"version": "7.2.5",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.3-rc2",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.18.52",
"versionStartIncluding": "3.15",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.2.5",
"versionStartIncluding": "3.15",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.3-rc2",
"versionStartIncluding": "3.15",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nftrace: Take trace_array reference before accessing its ftrace_ops\n\nThe trace instance files set_ftrace_filter and set_ftrace_notrace was\nupdated to work with specific trace instances (trace_arrays). The issue is\nthat when these files are opened, there is a small race window where it\nwill use the ftrace_ops from the inode-\u003eprivate pointer to get a reference\nto the trace_array and then take its reference. The problem is that the\nftrace_ops itself could be freed. If the rmdir on the instance happens at\nthe same time the set_ftrace_filter file is opened, the rmdir could have\nalso freed the ftrace_ops and referencing it will cause a use-after-free\nbug and crash the kernel.\n\nInstead, pass in the trace_array as the file private data (NULL for the\ntop level instance), and then pass both the trace_array and the ftrace_ops\nto the ftrace_regex_open() function. If the trace_array is NULL, then it\njust uses the ftrace_ops without the need to take its reference (like\nnormal). If the ftrace_ops is NULL, that is only the case for the top\nlevel instance and the global_ops can be used.\n\nThis allows the trace_array to have its reference incremented before\ntouching the ftrace_ops that could also be freed when the instance is."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 7.8,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"scenarios": [
{
"lang": "en",
"value": "AV:L - The UAF is reached only by a local open() of an instance set_ftrace_filter/set_ftrace_notrace racing rmdir of that tracing instance under /sys/kernel/tracing/instances; there is no network or adjacent-protocol path into ftrace_filter_open().\nAC:L - The attacker drives both sides: mkdir an instance, open its filter file on one thread, and rmdir it on another. instance_rmdir drops inode locks and kfree()s ftrace_ops before unlinking the files, so the race is retryable with no condition outside attacker control.\nPR:L - ftrace_regex_open()/instance mkdir/rmdir check only LOCKDOWN_TRACEFS (off by default) and DAC, with no capable() call. Android/Perfetto, ChromeOS, and distro tracing-group gid= mounts routinely grant unprivileged users write on /sys/kernel/tracing/instances.\nUI:N - The attacker performs mkdir, concurrent open of set_ftrace_filter/set_ftrace_notrace, and rmdir entirely from their own threads; no victim mount, click, or other-user action is required.\nS:U - The use-after-free is of a kmalloc\u0027d struct ftrace_ops in the host kernel heap; any privilege escalation stays within the kernel\u0027s own security authority and does not cross a VM, IOMMU, or sandbox boundary.\nC:H - This is a use-after-free of heap-allocated ftrace_ops: open() reads ops-\u003eprivate, ops-\u003eflags, and ops-\u003efunc_hash from the freed object, so after slab reclaim/spray those fields become attacker-controlled and yield an arbitrary kernel read.\nI:H - ftrace_ops_init() writes flags, func_hash, and a mutex into the freed object and later mutex_lock()s ops-\u003efunc_hash-\u003eregex_lock; with spray this is an arbitrary-write primitive, and ftrace_ops also carries hijackable function pointers (func, ops_func).\nA:H - Dereferencing the freed ftrace_ops (ops-\u003eprivate, flags, func_hash) on the open-versus-rmdir race reliably oopses or panics the kernel, as described in the fix, and can be re-triggered by repeating instance create/open/rmdir."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-09-16T14:41:18.991Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/83fd7eca5ab0d3ac3f23bff889175d847e21af06"
},
{
"url": "https://git.kernel.org/stable/c/cee8f286794df916553d8d445eac5c323ec5b0f8"
},
{
"url": "https://git.kernel.org/stable/c/9100191e5acb2e5ea2313f436667bb5fce129f47"
}
],
"title": "ftrace: Take trace_array reference before accessing its ftrace_ops",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-90002",
"datePublished": "2026-09-16T10:33:12.734Z",
"dateReserved": "2026-09-11T19:38:34.780Z",
"dateUpdated": "2026-09-16T14:41:18.991Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"nvd": "{\"cve\":{\"id\":\"CVE-2026-90002\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-09-16T11:17:12.697\",\"lastModified\":\"2026-09-16T15:18:24.020\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nftrace: Take trace_array reference before accessing its ftrace_ops\\n\\nThe trace instance files set_ftrace_filter and set_ftrace_notrace was\\nupdated to work with specific trace instances (trace_arrays). The issue is\\nthat when these files are opened, there is a small race window where it\\nwill use the ftrace_ops from the inode-\u003eprivate pointer to get a reference\\nto the trace_array and then take its reference. The problem is that the\\nftrace_ops itself could be freed. If the rmdir on the instance happens at\\nthe same time the set_ftrace_filter file is opened, the rmdir could have\\nalso freed the ftrace_ops and referencing it will cause a use-after-free\\nbug and crash the kernel.\\n\\nInstead, pass in the trace_array as the file private data (NULL for the\\ntop level instance), and then pass both the trace_array and the ftrace_ops\\nto the ftrace_regex_open() function. If the trace_array is NULL, then it\\njust uses the ftrace_ops without the need to take its reference (like\\nnormal). If the ftrace_ops is NULL, that is only the case for the top\\nlevel instance and the global_ops can be used.\\n\\nThis allows the trace_array to have its reference incremented before\\ntouching the ftrace_ops that could also be freed when the instance is.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"include/linux/ftrace.h\",\"kernel/trace/ftrace.c\",\"kernel/trace/trace.h\",\"kernel/trace/trace_functions.c\",\"kernel/trace/trace_stack.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"591dffdade9f07692a7dd3ed16830ec24e901ece\",\"lessThan\":\"83fd7eca5ab0d3ac3f23bff889175d847e21af06\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"591dffdade9f07692a7dd3ed16830ec24e901ece\",\"lessThan\":\"cee8f286794df916553d8d445eac5c323ec5b0f8\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"591dffdade9f07692a7dd3ed16830ec24e901ece\",\"lessThan\":\"9100191e5acb2e5ea2313f436667bb5fce129f47\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"include/linux/ftrace.h\",\"kernel/trace/ftrace.c\",\"kernel/trace/trace.h\",\"kernel/trace/trace_functions.c\",\"kernel/trace/trace_stack.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"3.15\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"3.15\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.52\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.2.5\",\"lessThanOrEqual\":\"7.2.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.3-rc2\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H\",\"baseScore\":7.8,\"baseSeverity\":\"HIGH\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":1.8,\"impactScore\":5.9}]},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/83fd7eca5ab0d3ac3f23bff889175d847e21af06\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/9100191e5acb2e5ea2313f436667bb5fce129f47\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/cee8f286794df916553d8d445eac5c323ec5b0f8\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}"
}
}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
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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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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.
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