DF-0300

ng_decodeidname truncates u_long to ng_ID_t without range check

Summary

strtoul returns u_long(64-bit). ng_decodeidname(:919-925) only rejects ULONG_MAX and 0, casts to ng_ID_t(uint32_t). Value>0xFFFFFFFF silently truncated. Harmless: lookup miss only. Root-only.

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Severity: Info
Status: new
Bucket: Base system — network stack
Confidence: certain
Pass: 1 · GLM 5.2 first pass
CVSS 3.1: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U:C:N/I:N/A:N
CWE: CWE-197
File: sys/netgraph7/netgraph/ng_base.c
Lines: 919-925
Area: net
Discovered: 2026-06-30
Updated: 2026-06-30

Team triage

untriaged

priority: — · owner: —

PoC verification

reproduced

Status: reproduced
Reproduced: yes
Impact: none
Confidence: certain
Tested: 2026-07-23 18:17:09
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: certain
Tested: 2026-07-23 18:17:09
Runtime: —
Kernel: combined build rc=0
fix.diff: findings/poc/DF-0300/fix.diff
Runner: df-bsd-pocrunner

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PoC verification

Evidence pack

findings/poc/DF-0300 · 1 files

File	Type	Description	Size
fix.diff	suggested-fix	ng_decodeidname truncates u_long to ng_ID_t without range check	284 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)

↓ fix.diffcombined build rc=0

Confirmed kernel references

—

Detail

Exploit chain

none (Info severity)

Evidence (decisive lines)

Source-confirmed at sys/netgraph7/netgraph/ng_base.c:919: ng_decodeidname truncates u_long to ng_ID_t without range check

Verified recommended fix

Source-confirmed at sys/netgraph7/netgraph/ng_base.c:919: ng_decodeidname truncates u_long to ng_ID_t without range check

Verdict

Source-confirmed at sys/netgraph7/netgraph/ng_base.c:919: ng_decodeidname truncates u_long to ng_ID_t without range check