FKIE_CVE-2026-89580
Vulnerability from fkie_nvd - Published: 2026-09-11 20:19 - Updated: 2026-09-13 07:17
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved:
bpf: Disable preemption in __bpf_get_stack
get_perf_callchain() returns a per-CPU perf_callchain_entry buffer and
releases its recursion slot via put_callchain_entry() before returning,
so nothing keeps the entry reserved while __bpf_get_stack() consumes
it below.
A preemptible BPF program (e.g. a non-sleepable raw tracepoint program
on a PREEMPT kernel, which runs under migrate_disable() but not
preempt_disable()) can be scheduled out between obtaining the entry
and the copy. Another task scheduled on the same CPU then reuses the
same per-CPU buffer and overwrites trace->nr with a larger value.
copy_len is then computed from the inflated trace->nr and can exceed
the caller's buffer, causing an out-of-bounds write in the memcpy()
and in the build_id path.
The rcu_read_lock() taken here alone does not prevent this. It is
only taken on the may_fault path, and under CONFIG_PREEMPT_RCU it does
not disable preemption; it merely keeps perf's callchain buffer array
alive (freed via call_rcu()) and does nothing to stop another task
from reusing the entry.
Disable preemption around obtaining the callchain entry and copying
it into the caller's buffer, so the entry cannot be reused underneath
us and trace->nr stays bounded by max_depth. Build ID resolution may
fault and is therefore deferred until after preemption is re-enabled;
by then the instruction pointers have already been copied into buf,
so it operates only on that private copy. Note, preempt_disable() also
subsumes the buffer-lifetime guarantee the rcu_read_lock() provided,
since a preempt-disabled section is an RCU read-side critical section
for the callchain buffers' call_rcu() reclaim.
[ changed Fixes: commit ]
References
Impacted products
| Vendor | Product | Version |
|---|
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"kernel/bpf/stackmap.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "8c5ba022f2085ea42d011497a6e92e527d123b9b",
"status": "affected",
"version": "c195651e565ae7f41a68acb7d4aa7390ad215de1",
"versionType": "git"
},
{
"lessThan": "dbfecc8a6631c0d3626c14ba1f1a485a4498445a",
"status": "affected",
"version": "c195651e565ae7f41a68acb7d4aa7390ad215de1",
"versionType": "git"
},
{
"lessThan": "9a23747909fcae707990c8466c381a0e7acfaa4e",
"status": "affected",
"version": "c195651e565ae7f41a68acb7d4aa7390ad215de1",
"versionType": "git"
},
{
"lessThan": "b1a47b2708d4e95dbd23aee2ec83752190897b3f",
"status": "affected",
"version": "c195651e565ae7f41a68acb7d4aa7390ad215de1",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"kernel/bpf/stackmap.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "4.18"
},
{
"lessThan": "4.18",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.109",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.50",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.2.*",
"status": "unaffected",
"version": "7.2.4",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.3-rc1",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Disable preemption in __bpf_get_stack\n\nget_perf_callchain() returns a per-CPU perf_callchain_entry buffer and\nreleases its recursion slot via put_callchain_entry() before returning,\nso nothing keeps the entry reserved while __bpf_get_stack() consumes\nit below.\n\nA preemptible BPF program (e.g. a non-sleepable raw tracepoint program\non a PREEMPT kernel, which runs under migrate_disable() but not\npreempt_disable()) can be scheduled out between obtaining the entry\nand the copy. Another task scheduled on the same CPU then reuses the\nsame per-CPU buffer and overwrites trace-\u003enr with a larger value.\ncopy_len is then computed from the inflated trace-\u003enr and can exceed\nthe caller\u0027s buffer, causing an out-of-bounds write in the memcpy()\nand in the build_id path.\n\nThe rcu_read_lock() taken here alone does not prevent this. It is\nonly taken on the may_fault path, and under CONFIG_PREEMPT_RCU it does\nnot disable preemption; it merely keeps perf\u0027s callchain buffer array\nalive (freed via call_rcu()) and does nothing to stop another task\nfrom reusing the entry.\n\nDisable preemption around obtaining the callchain entry and copying\nit into the caller\u0027s buffer, so the entry cannot be reused underneath\nus and trace-\u003enr stays bounded by max_depth. Build ID resolution may\nfault and is therefore deferred until after preemption is re-enabled;\nby then the instruction pointers have already been copied into buf,\nso it operates only on that private copy. Note, preempt_disable() also\nsubsumes the buffer-lifetime guarantee the rcu_read_lock() provided,\nsince a preempt-disabled section is an RCU read-side critical section\nfor the callchain buffers\u0027 call_rcu() reclaim.\n\n\n[ changed Fixes: commit ]"
}
],
"id": "CVE-2026-89580",
"lastModified": "2026-09-13T07:17:23.720",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "LOCAL",
"availabilityImpact": "HIGH",
"baseScore": 7.8,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"exploitabilityScore": 1.8,
"impactScore": 5.9,
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary"
}
]
},
"published": "2026-09-11T20:19:42.270",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/8c5ba022f2085ea42d011497a6e92e527d123b9b"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/9a23747909fcae707990c8466c381a0e7acfaa4e"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/b1a47b2708d4e95dbd23aee2ec83752190897b3f"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/dbfecc8a6631c0d3626c14ba1f1a485a4498445a"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Received"
}
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Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
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vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
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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.
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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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