Summary

LATENT — file does not compile (DF-0721). ng_sppp_units_len is unsigned char :103 max 255. Growth formula newlen=2*len+1 :122 produces >255 after 8 extensions. Back-assignment ng_sppp_units_len=newlen :134 truncates to 255. Search loop :116-117 terminates at 255 re-enters extension bcopy only copies 255 bytes bzero wipes mark at byte 255 (unit 2040) re-issues same unit number producing duplicate if_xname. ng_units_in_use :104 also unsigned char wraps at 256 interfaces. Fix: promote both to int (sibling ng_iface.c already uses int).

PoC verification

Evidence pack

findings/poc/DF-0722 · 5 files

File	Type	Description	Size
fix.diff	suggested-fix	Widen ng_sppp_units_len / cap growth.	433 B	view raw
VERDICT.md	verdict	source-confirmation + fix	1.0 KB	↓ raw
../_batch_low/fix_build.log	build-log	combined 80-fix kernel build (rc=0, -Werror)	5.6 MB	↓ download
../_batch_low/combined_all.patch	suggested-fix	all 80 fixes batched	20.0 KB	view raw
../_batch_low/env.txt	environment	guest uname + kern.version	247 B	view raw

VERDICT.md verdict source-confirmation + fix

↓ download raw

DF-0722 — Low-severity source-confirmation

Verdict: INCONCLUSIVE

Impact: dos Confidence: likely

Kernel ref: netgraph7/ng_sppp.c:122

Mechanism / why

LATENT: file does not compile (DF-0721); ng_sppp_units_len is unsigned char (max 255); newlen=2*len+1 overflows after 8 expansions. Source-confirmed in a non-compiling module.

Recommended fix

Widen ng_sppp_units_len / cap growth.

Phase 8 (combined build)

All 80 Low-severity fixes were batched into one patch (../_batch_low/combined_all.patch) and applied to the in-guest /usr/src. A single make -j6 nativekernel KERNCONF=X86_64_GENERIC completed rc=0 with 0 errors under -Werror (../_batch_low/fix_build.log). The GENERIC-compiled fixes (net/radix, netinet, netinet6, wlan, wlan_ccmp, wlan_wep, altq, if_mib) are build-validated; module-only/netgraph/ipfw3/netsmb/vlan/sl/disc fixes apply cleanly to source (those subsystems are optional, not compiled into GENERIC).

A standalone git apply-able fix.diff is in this folder.

Confirmed kernel references

Detail

Exploit chain

none (latent; source-confirmed)

Evidence (decisive lines)

DF-0722 [INCONCLUSIVE] - netgraph7/ng_sppp.c:122

PoC changes

fix.diff present in findings/poc/DF-0722/; batched into ../_batch_low/combined_all.patch

Verified recommended fix