Answer in brief
CVE-2026-98044 records a Unknown severity vulnerability in bpf: Reject legacy packet loads from callbacks. 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 | >=ce01a4e5cfac7adbe0be565f90cd32ecbb2f8337 <3484a99303912db62428494a9061212049027e57 || >=ee861486e377edc55361c08dcbceab3f6b6577bd <bc489c0c9b8c86bd7fac42cfd1bb152f042fca56 || >=ee861486e377edc55361c08dcbceab3f6b6577bd <e7d28823c662128caae63f14e16bd394916c139b || 928d354ae3557e8f755a227e67be88034eb3cd7f || 8a800497d9f6c2ec9c2c1ba7b71d0ac2ea7f7bbe || de1055e7f9e67af32b1f3376066272b04e5223c0 || 37ad2bb11e9de92cb7b94548705eeedd87f7d392 || 8674e2db06cff6b50f2216eed9a761d15425bb34 || d846d83bdacbd8f14fc45c63b8c1d22608452e1c || >=6.18.42 <6.18.53 || >=5.10.265 <5.11 || >=5.15.216 <5.16 || >=6.1.183 <6.2 || >=6.6.148 <6.7 || >=6.12.101 <6.13 || >=7.0.10 <7.1 | 3484a99303912db62428494a9061212049027e57, bc489c0c9b8c86bd7fac42cfd1bb152f042fca56, e7d28823c662128caae63f14e16bd394916c139b, 6.18.53, 5.11, 5.16, 6.2, 6.7, 6.13, 7.1 |
| Linux/Linuxgeneric | 7.1 | Not reported |
Published upstream
Sep 25, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 25, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 25, 2026
In the Linux kernel, the following vulnerability has been resolved: bpf: Reject legacy packet loads from callbacks check_ld_abs() models a failed BPF_LD_ABS or BPF_LD_IND in a subprogram as an implicit return with R0 set to zero. It calls prepare_func_exit() to explore this synthesized path. When the load is reached directly from a synchronous callback, prepare_func_exit() enforces the callback return contract and marks R0 precise. R0 is not derived from a real instruction on this path, so precision backtracking reaches the callback call with R0 still requested and triggers the "callback unexpected regs" verifier bug. A privileged program loader can therefore cause a verifier warning and an -EFAULT BPF_PROG_LOAD. These legacy packet-load instructions are deprecated. Reject them from callbacks rather than complicating their implicit-return model. Check all active frames before constructing the implicit return so nested static subprograms cannot hide the callback context. Global functions are verified independently with a fresh frame zero, so an active-frame check cannot identify a global function called from a callback. Also check the complete subprogram call graph during stack-depth validation and reject a function containing a legacy load when any caller is a callback. This covers global and static descendants without making has_ld_abs transitive, preserving its per-function BTF return-type check. Ordinary uses outside callbacks remain supported.
Quoted source text, attributed separately from HOL analysis.