CVE-2026-99163
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: tracing/histograms: Reject non-stacktrace fields for synthetic stacktrace fields In check_synth_field(), when a synthetic event field is a stacktrace (field->is_stack) and the histogram field is not a "long[" stacktrace array, validation falls through to the generic size and signedness comparison. Because parse_synth_field() sets a stacktrace field's type to "__data_loc unsigned long[]", its size is sizeof(u64) and synth_field_signed() marks it as signed. Consequently, any 8-byte signed scalar histogram field passes the fallback check, and its scalar value is subsequently dereferenced as a kernel stacktrace pointer in get_field_size() and trace_stack(). Furthermore, checking strstr(hist_field->type, "long[") is insufficient because tracepoint fields defined with __bitmask() or __rel_bitmask() also have type "__data_loc unsigned long[]" or "__rel_loc unsigned long[]", whilst create_hist_field() treats them as 4-byte scalar values without HIST_FIELD_FL_STACKTRACE. Propagate HIST_FIELD_FL_STACKTRACE to variable references and field variables (whilst excluding variable aliases from per-element stacktrace capture), and reject any mismatch between HIST_FIELD_FL_STACKTRACE and field->is_stack in check_synth_field().
View original CVE JSON
{
"id": "CVE-2026-99163",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-10-28T11:17:36.613",
"lastModified": "2026-10-28T11:17:36.613",
"vulnStatus": "Received",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntracing/histograms: Reject non-stacktrace fields for synthetic stacktrace fields\n\nIn check_synth_field(), when a synthetic event field is a stacktrace\n(field->is_stack) and the histogram field is not a \"long[\" stacktrace\narray, validation falls through to the generic size and signedness\ncomparison.\n\nBecause parse_synth_field() sets a stacktrace field's type to\n\"__data_loc unsigned long[]\", its size is sizeof(u64) and\nsynth_field_signed() marks it as signed. Consequently, any 8-byte\nsigned scalar histogram field passes the fallback check, and its scalar\nvalue is subsequently dereferenced as a kernel stacktrace pointer in\nget_field_size() and trace_stack().\n\nFurthermore, checking strstr(hist_field->type, \"long[\") is insufficient\nbecause tracepoint fields defined with __bitmask() or __rel_bitmask()\nalso have type \"__data_loc unsigned long[]\" or \"__rel_loc unsigned\nlong[]\", whilst create_hist_field() treats them as 4-byte scalar values\nwithout HIST_FIELD_FL_STACKTRACE.\n\nPropagate HIST_FIELD_FL_STACKTRACE to variable references and field\nvariables (whilst excluding variable aliases from per-element\nstacktrace capture), and reject any mismatch between\nHIST_FIELD_FL_STACKTRACE and field->is_stack in check_synth_field()."
}
],
"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": "00cf3d672a9dd409418647e9f98784c339c3ff63",
"lessThan": "1f36e4ddd05d540f363dbaa4c23042549f15b3ef",
"versionType": "git",
"status": "affected"
},
{
"version": "00cf3d672a9dd409418647e9f98784c339c3ff63",
"lessThan": "deb336ae7c7b341591a6862cf6fcfeca97c77dfd",
"versionType": "git",
"status": "affected"
},
{
"version": "00cf3d672a9dd409418647e9f98784c339c3ff63",
"lessThan": "a244c241593b5b38a08f0df2cb43c26574efbdcb",
"versionType": "git",
"status": "affected"
},
{
"version": "b9453380c1c542fd095a4dbe9251eeba4022bbce",
"versionType": "git",
"status": "affected"
},
{
"version": "5f52389bdd9eafb63b3a2f804e02aeb17b6a5f55",
"versionType": "git",
"status": "affected"
},
{
"version": "f3baa42afeea0d5f04ad31525e861199d02210cc",
"versionType": "git",
"status": "affected"
},
{
"version": "5.10.237",
"lessThan": "5.11",
"versionType": "semver",
"status": "affected"
},
{
"version": "5.15.124",
"lessThan": "5.16",
"versionType": "semver",
"status": "affected"
},
{
"version": "6.1.43",
"lessThan": "6.2",
"versionType": "semver",
"status": "affected"
}
]
},
{
"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": "6.3",
"status": "affected"
},
{
"version": "0",
"lessThan": "6.3",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18.59",
"lessThanOrEqual": "6.18.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.2.13",
"lessThanOrEqual": "7.2.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.3",
"lessThanOrEqual": "*",
"versionType": "original_commit_for_fix",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {},
"references": [
{
"url": "https://git.kernel.org/stable/c/1f36e4ddd05d540f363dbaa4c23042549f15b3ef",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/a244c241593b5b38a08f0df2cb43c26574efbdcb",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/deb336ae7c7b341591a6862cf6fcfeca97c77dfd",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
]
}