GHSA-8P9W-3QJG-CV4W
Vulnerability from github – Published: 2026-07-19 18:31 – Updated: 2026-07-19 18:31In the Linux kernel, the following vulnerability has been resolved:
tracing: Avoid NULL return from hist_field_name() on truncation
hist_field_name() returns "" everywhere except the fully-qualified VAR_REF/EXPR case, where snprintf() truncation returns NULL early and bypasses the bottom NULL->"" guard. Callers don't expect NULL: strcat(expr, hist_field_name(field, 0)) at trace_events_hist.c:1758 and the strcmp() in the sort-key match loop at :4804 both deref it.
system and event_name are bounded by MAX_EVENT_NAME_LEN, but the field name on a VAR_REF is kstrdup'd from a histogram variable name parsed out of the trigger string and has no length cap, so a long enough var name in a fully qualified reference can reach the truncation path.
Keep the length check but leave field_name as "" on overflow.
{
"affected": [],
"aliases": [
"CVE-2026-64028"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-07-19T16:17:42Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\ntracing: Avoid NULL return from hist_field_name() on truncation\n\nhist_field_name() returns \"\" everywhere except the fully-qualified\nVAR_REF/EXPR case, where snprintf() truncation returns NULL early\nand bypasses the bottom NULL-\u003e\"\" guard. Callers don\u0027t expect NULL:\nstrcat(expr, hist_field_name(field, 0)) at trace_events_hist.c:1758\nand the strcmp() in the sort-key match loop at :4804 both deref it.\n\nsystem and event_name are bounded by MAX_EVENT_NAME_LEN, but the\nfield name on a VAR_REF is kstrdup\u0027d from a histogram variable\nname parsed out of the trigger string and has no length cap, so\na long enough var name in a fully qualified reference can reach\nthe truncation path.\n\nKeep the length check but leave field_name as \"\" on overflow.",
"id": "GHSA-8p9w-3qjg-cv4w",
"modified": "2026-07-19T18:31:50Z",
"published": "2026-07-19T18:31:50Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64028"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/0402a1d3ddec565132867337ed44514a09d84728"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/37377b39ff86dacbc533275c1155210d4fd5dc91"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/576ec047d20b368b43c4d5db98c4f2e0f3c101ec"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/915c1254fe0788abddc31095b360e9dc98907a34"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/be4e99038c1603fa6b329d8ee3e364825e17c353"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/d6c8b3ebdcdb12b59ad4212acb137cc56cae453d"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/e3f5d42cdc2f167719564693675f1eead81378ea"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/e91687643c440ca3997d67646e6f80b92edc6703"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
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