bug(parser): kics-scan ignore-line/ignore-block misapplied in YAML files with resolved references

[theo-sardin]

Expected Behavior

In a YAML file that references other files (e.g. a docker-compose include:), # kics-scan ignore-line should suppress the finding on the line beneath it, and lines without an ignore comment should apply warnings as usual.

For the reproduction below: foo's port finding is suppressed, while bar's port finding is reported.

Actual Behavior

The ignore positions seem to be shifted by the resolved (inlined) content, so:

• foo is reported at line 8 — despite the ignore-line comment right above its ports:
• bar is silently suppressed, although it has no ignore comment (the shifted ignore lands on it)

Container Traffic Not Bound To Host Interface, Severity: MEDIUM, Results: 1
    [1]: docker-compose.yaml:8

Steps to Reproduce the Problem

1. Create docker-compose.yaml:

include:
  - included.yaml
services:
  foo:
    image: alpine
    # kics-scan ignore-line
    ports:
      - "1111:1111"
  bar:
    image: alpine
    ports:
      - "2222:2222"

2. Create included.yaml next to it:

services:
  rabbit:
    image: rabbitmq:3
    environment:
      K0: "0"
      K1: "1"
      K2: "2"

3. Run kics scan -p docker-compose.yaml (narrowing to the ports query shows it clearly: --include-queries 451d79dc-0588-476a-ad03-3c7f0320abb3)

Specifications

• Version: reproduced on current master and v2.1.20
• Platform: any YAML platform with resolved file references

Root cause

Parser.Parse first resolves the referenced files (the resolver inlines included.yaml, shifting all lines below the include: block), then collects the ignore comment positions from the resolved content. Then we store the shifted positions in FileMetadata.LinesIgnore (pkg/kics/sink.go). Findings, however, are reported on original file coordinates, so checkComment(vulnerability.Line, file.LinesIgnore) (pkg/engine/inspector.go) compares two different coordinate systems. In the repro, the comment at original lines 6-7 is stored as [12, 13].

Two other places already handle this by recomputing ignore lines from the original data: the secrets engine (model.GetIgnoreLines in pkg/engine/secrets/inspector.go, added in #5735) and the Helm sink (getOriginalIgnoreLines in pkg/kics/resolver_sink.go). The regular sink doesn't have such fix.

Issues I think are related:

• Ansible include causes kics to ignore it's ignore patterns #5685 (closed) — "Ansible include causes kics to ignore its ignore patterns": most likely the same root cause.
• fix(resolver): consider comments in YAML resolver #5735 — fixed Ansible include causes kics to ignore it's ignore patterns #5685, but only for the secrets engine (introduced the model.GetIgnoreLines recompute in pkg/engine/secrets/inspector.go). I think it's most likely an oversight to not have done the more "catch all" fix initially.
• query<Kubernetes>: kics-scan ignore-block not working for YAML files #7054 (open) — kics-scan ignore-block not working in a templated Kubernetes YAML; likely the same family of problem ?

I have a fix ready, PR coming.