Answer in brief
CVE-2026-89984 records a Unknown severity vulnerability in perf/x86/intel: Fix kernel address leakages in LBR stack. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=47125db27e47e9d44c878bf8925aa057824bb0d5 <f3705db4e6378cc1b91a38ce0fe2f879055e23ca || >=47125db27e47e9d44c878bf8925aa057824bb0d5 <b589147f54adc62e4172e4acf079ad5fb7b3687f || >=47125db27e47e9d44c878bf8925aa057824bb0d5 <be0628a101ac05b085aaa4f650d48bd3915e80fa || >=47125db27e47e9d44c878bf8925aa057824bb0d5 <ca19a175e89b7de604fab736436cbab74030b47a || >=47125db27e47e9d44c878bf8925aa057824bb0d5 <6ac26161db27f7fb9d9e89ae240dbe52795496cc || >=47125db27e47e9d44c878bf8925aa057824bb0d5 <3c492c8eba02698ca893a9a13388d2adf6dfb839 || >=47125db27e47e9d44c878bf8925aa057824bb0d5 <68c4b780b266a435261a1e029bede5ee3c2735cc || >=47125db27e47e9d44c878bf8925aa057824bb0d5 <e2b0575900ff72aa82748af96e7bd564ade5157a | f3705db4e6378cc1b91a38ce0fe2f879055e23ca, b589147f54adc62e4172e4acf079ad5fb7b3687f, be0628a101ac05b085aaa4f650d48bd3915e80fa, ca19a175e89b7de604fab736436cbab74030b47a, 6ac26161db27f7fb9d9e89ae240dbe52795496cc, 3c492c8eba02698ca893a9a13388d2adf6dfb839, 68c4b780b266a435261a1e029bede5ee3c2735cc, e2b0575900ff72aa82748af96e7bd564ade5157a |
| Linux/Linuxgeneric | 5.9 | Not reported |
Published upstream
Sep 16, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 19, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 16, 2026
In the Linux kernel, the following vulnerability has been resolved: perf/x86/intel: Fix kernel address leakages in LBR stack Before Arch LBR gained CPL filtering support, a user-only branch stack could still contain kernel addresses. As a result, kernel branch records may be exposed to user space even when PERF_SAMPLE_BRANCH_USER is requested. For example, on Intel Tiger Lake, the following command can still report SYSRET/ERET entries with kernel-space from addresses: $ ./perf record -e cycles:p -o - --branch-filter any,save_type,u -- \ ./perf bench syscall basic --loop 1000 | \ ./perf script -i - --fields brstack|tr ' ' '\n'| \ grep -E '0x[89a-f][0-9a-f]{15}' Total time: 0.000 [sec] 0.219000 usecs/op 4,566,210 ops/sec [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.551 MB - ] 0xffffffff93c001c8/0x7f12a2b1d647/P/-/-/16959/SYSRET/- 0xffffffff93c001c8/0x7f12a2b1d5c2/P/-/-/17535/SYSRET/- 0xffffffff93c01928/0x7f12a2861000/P/-/-/6719/ERET/- 0xffffffff93c01928/0x7f12a297a000/P/-/-/8575/ERET/- The problem is that intel_pmu_lbr_filter() does not fully validate the privilege level of sampled entries. It filters some mismatches based on the branch type and the to address, but it does not reject entries whose from address violates the requested branch privilege filter. Fix this by extending software filtering to validate both from and to addresses against br_sel. Any LBR entry contains kernel address does not match the requested user filter is dropped. This prevents kernel addresses from appearing in user-only branch stacks.
Quoted source text, attributed separately from HOL analysis.