DF-0180

Fragile zeroing contract for fill_kinfo_lwp aggregation (+=)

Summary

fill_kinfo_lwp does NOT bzero output (unlike fill_kinfo_proc:126 and fill_kinfo_proc_kthread:286). Uses += on tick/pctcpu/slptime fields(:257-262) and ruadd(:267). Correctness depends on caller pre-zeroing. Current kernel caller correct (kern_proc.c:1601,1613). Latent regression risk.

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Severity: Info
Status: new
Bucket: Kernel memory leaks / uninitialized disclosure
Confidence: likely
Pass: 1 · GLM 5.2 first pass
CVSS 3.1: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:N
CWE: CWE-908
File: sys/kern/kern_kinfo.c
Lines: 219-267
Area: kern
Discovered: 2026-06-30
Updated: 2026-06-30

Team triage

untriaged

priority: — · owner: —

PoC verification

reproduced

Status: reproduced
Reproduced: yes
Impact: none
Confidence: likely
Tested: 2026-07-23 18:17:06
Attempts: —
Runtime: —
Code hash: —
Guest: DragonFly dfbsd 6.5-DEVELOPMENT #0
Build cmd: —
Run cmd: —

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Fix verification

fixed

Fix status: fixed
Baseline reproduced: yes
Patched reproduced: no
Confidence: likely
Tested: 2026-07-23 18:17:06
Runtime: —
Kernel: combined build rc=0
fix.diff: findings/poc/DF-0180/fix.diff
Runner: df-bsd-pocrunner

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PoC verification

Evidence pack

findings/poc/DF-0180 · 1 files

File	Type	Description	Size
manifest.json	file		386 B	view raw

Fix verification

fixed

baseline reproduced→ patch + rebuild →patched clean

fix.diff applied + combined nativekernel build rc=0 (-Werror)

fix.diff applied + combined nativekernel build rc=0 (-Werror)

combined build rc=0

Confirmed kernel references

—

Detail

Exploit chain

none (Info severity)

Evidence (decisive lines)

Source-confirmed at sys/kern/kern_kinfo.c:219: fragile zeroing contract for fill_kinfo_lwp aggregation

Verified recommended fix

Source-confirmed at sys/kern/kern_kinfo.c:219: fragile zeroing contract for fill_kinfo_lwp aggregation

Verdict

Source-confirmed at sys/kern/kern_kinfo.c:219: fragile zeroing contract for fill_kinfo_lwp aggregation