CVE-2026-99163
Received Received - Intake

BaseFortify

Publication date: 2026-10-28

Last updated on: 2026-10-28

Assigner: kernel.org

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().

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Meta Information

Published
2026-10-28
Last Modified
2026-10-28
Generated
2026-10-28
AI Q&A
2026-10-28
EPSS Evaluated
N/A
NVD
CVE-2026-99163
EUVD
EUVD-2026-111915

Affected Vendors & Products

Showing 10 associated CPEs
Vendor Product Version / Range
Linux Linux 00cf3d672a9dd409418647e9f98784c339c3ff63
Linux Linux 00cf3d672a9dd409418647e9f98784c339c3ff63
Linux Linux 00cf3d672a9dd409418647e9f98784c339c3ff63
Linux Linux b9453380c1c542fd095a4dbe9251eeba4022bbce
Linux Linux 5f52389bdd9eafb63b3a2f804e02aeb17b6a5f55
Linux Linux f3baa42afeea0d5f04ad31525e861199d02210cc
Linux Linux 5.10.237
Linux Linux 5.15.124
Linux Linux 6.1.43
Linux Linux 6.3

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Exploitability

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CWE ID Description
CWE-UNKNOWN

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Executive Summary

This vulnerability in the Linux kernel involves incorrect validation of synthetic stacktrace fields in tracing histograms. When a synthetic event field is marked as a stacktrace but the histogram field is not a proper stacktrace array, the system incorrectly allows non-stacktrace fields to pass validation. This happens because the type checking falls through to a generic comparison that does not account for stacktrace-specific requirements.

Impact Analysis

This vulnerability could allow an attacker to manipulate kernel tracing mechanisms by providing invalid stacktrace fields. This might lead to memory corruption or crashes in the kernel, potentially causing denial-of-service conditions or privilege escalation if exploited.

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