{"cve":"CVE-2026-99163","nvd":{"published":"2026-10-28T11:17:36.613","modified":"2026-10-28T11:17:36.613","status":"Received","description":"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().","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/1f36e4ddd05d540f363dbaa4c23042549f15b3ef","https://git.kernel.org/stable/c/a244c241593b5b38a08f0df2cb43c26574efbdcb","https://git.kernel.org/stable/c/deb336ae7c7b341591a6862cf6fcfeca97c77dfd"],"products":[],"source":"nvd","synced_at":"2026-10-28T11:37:51.394563875+00:00"},"epss":null,"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}