CVE-2026-80916 (GCVE-0-2026-80916)
Vulnerability from cvelistv5
Published
2026-09-09 16:13
Modified
2026-10-19 08:45
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
kcov: fix data corruption and race conditions on PREEMPT_RT
syzbot is reporting KCOV state corruption on PREEMPT_RT kernels, for the
temporary storage used for saving/restoring remote KCOV state is currently
allocated as the per-CPU area.
On PREEMPT_RT kernels, softirq handlers run as preemptible task threads
(e.g., ksoftirqd). If a softirq context preempts a task running a remote
KCOV session, it safely saves the task's state into the per-CPU area.
However, if that softirq thread is subsequently preempted by a higher-
priority softirq thread on the same CPU, the second softirq will overwrite
the same per-CPU area, permanently destroying the original task's KCOV
state.
Fix this data corruption by moving the temporary storage from the per-CPU
area to the per-thread area. Since each softirq thread now owns its own
task context, nested softirq preemption no longer causes data overwrites.
Note that while the temporary storage is now on a per-thread basis, the
per-CPU kcov_percpu_data.lock must be retained, for we need to ensure that
kcov_remote_start() and kcov_remote_stop() operate atomically without
racing against asynchronous interrupts that manipulate the current task's
KCOV state.
It is likely that GFP_KERNEL allocation by vmalloc_node() in kcov_init()
has already called panic() before returning NULL, for there will be no
OOM-killable userspace processes when __init function of built-in module
runs. But this patch also fixes crashing the kernel when vmalloc_node()
in kcov_init() returned NULL, for kcov_init() left per-CPU irq_area == NULL
but kcov_remote_start() depends on per-CPU irq_area != NULL, resulting in
(1) doing vmalloc() in kcov_remote_start() despite !in_task() context
(2) out-of-array-bounds access if (1) succeeded but
kcov->remote_size < CONFIG_KCOV_IRQ_AREA_SIZE
(3) always leak memory allocated by (1), eventually killing all
OOM-killable userspace processes
problems.
References
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Linux | Linux |
Version: 5ff3b30ab57da82d8db4f14662a2858cabfbc2c0 Version: 5ff3b30ab57da82d8db4f14662a2858cabfbc2c0 Version: 5ff3b30ab57da82d8db4f14662a2858cabfbc2c0 Version: 5ff3b30ab57da82d8db4f14662a2858cabfbc2c0 Version: 5ff3b30ab57da82d8db4f14662a2858cabfbc2c0 Version: 5ff3b30ab57da82d8db4f14662a2858cabfbc2c0 Version: 5ff3b30ab57da82d8db4f14662a2858cabfbc2c0 Version: 5ff3b30ab57da82d8db4f14662a2858cabfbc2c0 Version: 5ff3b30ab57da82d8db4f14662a2858cabfbc2c0 |
||
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"include/linux/sched.h",
"kernel/kcov.c",
"lib/Kconfig.debug"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "ef7048d8a614c5f5a9b20513a5428101a744514e",
"status": "affected",
"version": "5ff3b30ab57da82d8db4f14662a2858cabfbc2c0",
"versionType": "git"
},
{
"lessThan": "8ed3ddf23d39bf5338406bd9f8863d44748cf6ce",
"status": "affected",
"version": "5ff3b30ab57da82d8db4f14662a2858cabfbc2c0",
"versionType": "git"
},
{
"lessThan": "5dc59fc959b2b5742985d7ef24bccd1868217dc2",
"status": "affected",
"version": "5ff3b30ab57da82d8db4f14662a2858cabfbc2c0",
"versionType": "git"
},
{
"lessThan": "a2fb8222cde23b0001812ed3acb7c0ea36dd94e2",
"status": "affected",
"version": "5ff3b30ab57da82d8db4f14662a2858cabfbc2c0",
"versionType": "git"
},
{
"lessThan": "18799e858b407bf355383c9dd6c06477aa437134",
"status": "affected",
"version": "5ff3b30ab57da82d8db4f14662a2858cabfbc2c0",
"versionType": "git"
},
{
"lessThan": "e11f5b48c82703242a3be7a7ae4b4940b4cb4610",
"status": "affected",
"version": "5ff3b30ab57da82d8db4f14662a2858cabfbc2c0",
"versionType": "git"
},
{
"lessThan": "22670d1552fe155822b2abf91f920925f7d067b4",
"status": "affected",
"version": "5ff3b30ab57da82d8db4f14662a2858cabfbc2c0",
"versionType": "git"
},
{
"lessThan": "f8c9a3ec36b4ee3d4701b9be08f40e7bfbf89761",
"status": "affected",
"version": "5ff3b30ab57da82d8db4f14662a2858cabfbc2c0",
"versionType": "git"
},
{
"lessThan": "2eed77fdcb0cc48e8eccb2bcd4b7f2c6d650e84c",
"status": "affected",
"version": "5ff3b30ab57da82d8db4f14662a2858cabfbc2c0",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"include/linux/sched.h",
"kernel/kcov.c",
"lib/Kconfig.debug"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "5.8"
},
{
"lessThan": "5.8",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.269",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.220",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.185",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.154",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.106",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.47",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.11",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.2.*",
"status": "unaffected",
"version": "7.2.1",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.10.269",
"versionStartIncluding": "5.8",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.15.220",
"versionStartIncluding": "5.8",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.1.185",
"versionStartIncluding": "5.8",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.6.154",
"versionStartIncluding": "5.8",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.12.106",
"versionStartIncluding": "5.8",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.18.47",
"versionStartIncluding": "5.8",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.1.11",
"versionStartIncluding": "5.8",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.2.1",
"versionStartIncluding": "5.8",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.3",
"versionStartIncluding": "5.8",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nkcov: fix data corruption and race conditions on PREEMPT_RT\n\nsyzbot is reporting KCOV state corruption on PREEMPT_RT kernels, for the\ntemporary storage used for saving/restoring remote KCOV state is currently\nallocated as the per-CPU area.\n\nOn PREEMPT_RT kernels, softirq handlers run as preemptible task threads\n(e.g., ksoftirqd). If a softirq context preempts a task running a remote\nKCOV session, it safely saves the task\u0027s state into the per-CPU area.\nHowever, if that softirq thread is subsequently preempted by a higher-\npriority softirq thread on the same CPU, the second softirq will overwrite\nthe same per-CPU area, permanently destroying the original task\u0027s KCOV\nstate.\n\nFix this data corruption by moving the temporary storage from the per-CPU\narea to the per-thread area. Since each softirq thread now owns its own\ntask context, nested softirq preemption no longer causes data overwrites.\n\nNote that while the temporary storage is now on a per-thread basis, the\nper-CPU kcov_percpu_data.lock must be retained, for we need to ensure that\nkcov_remote_start() and kcov_remote_stop() operate atomically without\nracing against asynchronous interrupts that manipulate the current task\u0027s\nKCOV state.\n\nIt is likely that GFP_KERNEL allocation by vmalloc_node() in kcov_init()\nhas already called panic() before returning NULL, for there will be no\nOOM-killable userspace processes when __init function of built-in module\nruns. But this patch also fixes crashing the kernel when vmalloc_node()\nin kcov_init() returned NULL, for kcov_init() left per-CPU irq_area == NULL\nbut kcov_remote_start() depends on per-CPU irq_area != NULL, resulting in\n\n (1) doing vmalloc() in kcov_remote_start() despite !in_task() context\n\n (2) out-of-array-bounds access if (1) succeeded but\n kcov-\u003eremote_size \u003c CONFIG_KCOV_IRQ_AREA_SIZE\n\n (3) always leak memory allocated by (1), eventually killing all\n OOM-killable userspace processes\n\nproblems."
}
],
"providerMetadata": {
"dateUpdated": "2026-10-19T08:45:00.547Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/ef7048d8a614c5f5a9b20513a5428101a744514e"
},
{
"url": "https://git.kernel.org/stable/c/8ed3ddf23d39bf5338406bd9f8863d44748cf6ce"
},
{
"url": "https://git.kernel.org/stable/c/5dc59fc959b2b5742985d7ef24bccd1868217dc2"
},
{
"url": "https://git.kernel.org/stable/c/a2fb8222cde23b0001812ed3acb7c0ea36dd94e2"
},
{
"url": "https://git.kernel.org/stable/c/18799e858b407bf355383c9dd6c06477aa437134"
},
{
"url": "https://git.kernel.org/stable/c/e11f5b48c82703242a3be7a7ae4b4940b4cb4610"
},
{
"url": "https://git.kernel.org/stable/c/22670d1552fe155822b2abf91f920925f7d067b4"
},
{
"url": "https://git.kernel.org/stable/c/f8c9a3ec36b4ee3d4701b9be08f40e7bfbf89761"
},
{
"url": "https://git.kernel.org/stable/c/2eed77fdcb0cc48e8eccb2bcd4b7f2c6d650e84c"
}
],
"title": "kcov: fix data corruption and race conditions on PREEMPT_RT",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-80916",
"datePublished": "2026-09-09T16:13:14.587Z",
"dateReserved": "2026-08-26T14:34:25.801Z",
"dateUpdated": "2026-10-19T08:45:00.547Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
Loading…
Loading…
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.
Loading…
Loading…