CVE-2026-99235
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: tracing: Save the event file instead of the compatible histogram create_field_var_hist() creates a histogram on the matched event to supply a field variable, and records it on the target so it can be torn down later: hist_data = find_compatible_hist(target_hist_data, file); ... /* Save the compatible histogram information */ var_hist->hist_data = hist_data; hist_data is not the histogram it creates. It is one that was already there, whose keys the new one copies. The saved pointer has a single user, unregister_field_var_hists(), which runs when the target is removed: file = hist_data->field_var_hists[i]->hist_data->event_file; find_compatible_hist() matches on keys alone, so it can pick one with no variables of its own. check_var_refs() then returns false and the user can remove it while the target still points at it: BUG: KASAN: slab-use-after-free in event_hist_trigger_free+0x2b2/0x320 Read of size 8 at addr ffff8880093b90e0 by task init/1 Freed by task 1: kfree+0x154/0x420 event_hist_trigger_free+0x1d5/0x320 event_hist_trigger_parse+0x35f3/0x69e0 trigger_process_regex+0x1a6/0x250 Save the event file instead. It is all the dereference ever wanted, and it does not go away when the user removes a trigger.
Severity
HIGH
CVSS score
7.8
(v3.1)
Vulnerability status
Received
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-11-02 16:17:48.790000
Last modified
2026-11-02 16:17:48.790000
View original CVE JSON
{
"id": "CVE-2026-99235",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-11-02T16:17:48.790",
"lastModified": "2026-11-02T16:17:48.790",
"vulnStatus": "Received",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntracing: Save the event file instead of the compatible histogram\n\ncreate_field_var_hist() creates a histogram on the matched event to\nsupply a field variable, and records it on the target so it can be torn\ndown later:\n\n\thist_data = find_compatible_hist(target_hist_data, file);\n\t...\n\t/* Save the compatible histogram information */\n\tvar_hist->hist_data = hist_data;\n\nhist_data is not the histogram it creates. It is one that was already\nthere, whose keys the new one copies. The saved pointer has a single\nuser, unregister_field_var_hists(), which runs when the target is\nremoved:\n\n\tfile = hist_data->field_var_hists[i]->hist_data->event_file;\n\nfind_compatible_hist() matches on keys alone, so it can pick one with no\nvariables of its own. check_var_refs() then returns false and the user\ncan remove it while the target still points at it:\n\n BUG: KASAN: slab-use-after-free in event_hist_trigger_free+0x2b2/0x320\n Read of size 8 at addr ffff8880093b90e0 by task init/1\n\n Freed by task 1:\n kfree+0x154/0x420\n event_hist_trigger_free+0x1d5/0x320\n event_hist_trigger_parse+0x35f3/0x69e0\n trigger_process_regex+0x1a6/0x250\n\nSave the event file instead. It is all the dereference ever wanted, and\nit does not go away when the user removes a trigger."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"kernel/trace/trace_events_hist.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "02205a6752f223779a1b0e9e8ffacbea6e717851",
"lessThan": "a6165126b1a1b26342b55be6eb6ee23af8756aba",
"versionType": "git",
"status": "affected"
},
{
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"lessThan": "173914501b97236d7ea7dc2af7f30feddd4e1436",
"versionType": "git",
"status": "affected"
},
{
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"versionType": "git",
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"versionType": "git",
"status": "affected"
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"versionType": "git",
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{
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"lessThan": "9631dbccd3c649b567a5aafffea6b00634183997",
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{
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}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"kernel/trace/trace_events_hist.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "4.17",
"status": "affected"
},
{
"version": "0",
"lessThan": "4.17",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.10.273",
"lessThanOrEqual": "5.10.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.15.224",
"lessThanOrEqual": "5.15.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.1.191",
"lessThanOrEqual": "6.1.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.6.161",
"lessThanOrEqual": "6.6.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.12.115",
"lessThanOrEqual": "6.12.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18.60",
"lessThanOrEqual": "6.18.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.2.14",
"lessThanOrEqual": "7.2.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.3.1",
"lessThanOrEqual": "7.3.*",
"versionType": "semver",
"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/173914501b97236d7ea7dc2af7f30feddd4e1436",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/3609ada3c12cecfb0ae5ee82ef4f86c5f18a2dea",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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{
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"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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{
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"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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{
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"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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{
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"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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{
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{
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}
]
}